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There are several works that I will cite below, that are NOT in my
personal library. Below are the ones that I will refer to by abbreviation:
[X01:FPvol8] Fish Physiology, volume VIII: Bioenergetics and Growth.
W.S. Hoar, D. J. Randall, and J.R. Brett (eds.). Academic Press:1979.
[X01:FPvol5] Fish Physiology, volume V: Sensory Systems and
Organs. W.S. Hoar and D. J. Randal (eds). Academic:1971.
[X01:FPvol6] Fish Physiology, volume VI: Environmental Relations
and Behavior. W.S. Hoar and D. J. Randal (eds). Academic:1971.
[X01:FPvol4] Fish Physiology, volume IV: The Nervous System,
Circulation, and Respiration. W.S. Hoar and D. J. Randal (eds). Academic:1970.
[X01:TP] The Predators. Irene E. Cohen, Putnum:1978.
[X01:AP] Animal Parasites. Jean G. Baer, McGraw-Hill:1971.
[X01:BP] The Biology of Populations. Robert MacArthur and Joseph
Connell. John Wiley:1960.
[X01:PF] The Physiology of Fishes. David H. Evans (ed.). CRC
Press:1997.
[X01:HBB] Hormones, Brain, and Behavior (Biology of the Reptilia).
Carl Gans and David Crews (eds). UChicagoPress:1992.
[X01:BRvol8] Biology of the Reptilia, volume 8: Physiology B.
Carl Gans (ed). Academic Press:1978.
[X01:BF] The Biology of Fishes. Q. Bone, N.B. Marshall, and
J.H.S. Baxter. Chapman&Hall:1995.
[X01:BFCB] The Biology of Fishes. Carl E. Bond. SaundersCollege:1996
(2nd ed).
[X01:CBF] The Chemical Biology of Fishes, volume 2: Advances 1968-1977.
R. Malcolm Love. Academic Press:1980.
[X01:EBF] Environmental Biology of Fishes. Malcolm Jobling.
Chapman&Hall:1995]
[X01:PAI] Plant-Animal Interactions. Warren G. Abrahamson (ed).
McGraw-Hill:1989]
[X01:WBFAR] Why Big Fierce Animals are Rare--an Ecologist's Perspective.
Paul Colinvaux. Princeton:1978.
[X01:SLS] The Ecology of the Seas, D.H. Cushing and J.J. Walsh
(eds.), W.B. Saunders:1976.
[X01:SME] The Structure of Marine Ecosystems, John H. Steele,
Harvard:1974.
[X01:ME] Marine Ecology. Otto Kinne (ed.). Wiley-Interscience:1978.
[X01:MON] The Machinery of Nature. Paul R. Ehrich. Simon and
Schuster:1988.
[X01:CDDAW] Carrion and Dung: the decomposition of animal wastes
(The Institute of Biology's Studies in Biology no. 156). Roderick J. Putnam.
Edward Arnold:1983.
[X01:IK] Innocent Killers. Hugo and Jane van Lawick-Goodall.
Houghton-Mifflin:1971.
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Question Two: How extensive is 'painful predation'? (In other words, DO all things live only at the expense of agonizing death by those lower on the food chain?)
Here we will have to cover a good bit of ecological and biological data...
The three keywords that I will organize this mass of data around are: "All", "Death", and "Agonizing".
First "Agonizing": All things live at the expense of agonizing death by those lower on the food chain.
What we have to do here is try to make some reasonable judgments as
to what types of organisms actually can even 'experience' agony. Do the
bacteria that my white blood cells engulf feel anything that could be remotely
called 'agony'? Does the potted plant that I cut a flower from last week
for my girlfriend still carry an emotional scar from the agony? Do
the single-celled phytoplankton known as diatoms of the sea (without nervous
system) feel torture as they are eaten by the slightly larger zooplankton?
Before we get into the data, we have to set out a couple of methodological points:
One, simple avoidance response to noxious stimuli on the part of an organism is not an adequate criterion for 'agony'. Single-celled organisms without a trace of nervous system (one rather obvious requirement for 'feeling' anything) manifest this behavior, but to predicate 'conscious agony' would be a stretch only a pan-psychist (or really consistent process philosopher) could make! The fact that a worm wiggles when stepped on will not be adequate evidence--by itself--for 'agony'.Okay, these are reasonable starting points, so let's look into the natural world to make some initial cut at separating the non-pain-feelers from the pain-feelers.ALL living things manifest was is called irritability [EBE, s.v. "Nerves and Nervous Systems: INTRACELLULAR SYSTEMS"]
"All living cells have the property of irritability, or responsiveness to environmental stimuli, which can affect the cell in different ways, producing, for example, electrical, chemical, or mechanical changes. These changes are expressed as a response, which may be the release of secretory products by gland cells, the contraction of muscle cells, the bending of a plant-stem cell, and the beating of whiplike "hairs," or cilia, by ciliated cells.But just "initiating a response" is too broad a term--sunlight 'initiates a response' in plant of cutting on the food-making engines, but this is not in the same category as the howling of a mammal whose leg is caught in a fur trap. The process of response initiation (e.g., nerve conduction or immediate chemical release) has to be considered."The responsiveness of a single cell can be illustrated by the behavior of the relatively simple amoeba. Unlike some other protozoans, an amoeba lacks highly developed structures that function in the reception of stimuli and in the production or conduction of a response. The amoeba behaves as though it had a nervous system, however, because the general responsiveness of its cytoplasm serves the functions of a nervous system. An excitation produced by a stimulus is conducted to other parts of the cell and evokes a response by the animal. An amoeba will move to a region of a certain level of light. It will be attracted by chemicals given off by foods and exhibit a feeding response. It will also withdraw from a region with noxious chemicals and show an avoidance reaction upon contacting other objects."
Two, we are going to need some loci for the agony sensation to converge on, for there to be "something" to experience "agony".
Let me illustrate what I mean by this from personal experience. In the early 1970's, I had a small growth removed from a joint in one of my fingers. The operation was done in an outpatient setting, with me being fully awake. They wrapped a rubber tube/band around my bicep, essentially cutting off most 'communication' between my brain and my hand. They then fed a powerful anesthetic into that section of my arm. They then did the 'slice and dice' on my hand, with deep incisions and peeling skin back and all that. But I didn't feel a thing--whatever sensations would have been 'agony' never reached 'me'. For all practical purposes, my nervous system was functioning as a 'segmented' nervous system. Did my arm 'feel agony', as violence was being perpetrated on it? Not by any current definitions of pain.
This, of course, is how anesthesia sorta works--it keeps the 'bad news' from reaching some higher-order, self-aware nerve integration point. There was certainly cell damage and "screaming" nerve transmissions, but my arm didn't try to defend itself because its motions are controlled by an agency "beyond the rubber tube line."
What this will imply for our study is that only organisms with non-segmented nervous systems and with some central integration site will be candidates for having something "there" to experience agony.
Three, from the above situation we can also infer that cell damage or destruction (and possibly even death itself) is not an adequate criterion for experiencing agony. If the nerves and the skin and the muscles and the vascular system of my hand were being sliced open by the scalpel, and yet I felt no agony at all because no 'signals' were reaching my center of consciousness, then the fact of damage alone cannot serve to differentiate between agony and non-agony. If whoever kills me first anesthetizes me, then my death cannot be perceived as 'agonized'.
.................................................................................................................
We have five Kingdoms to examine:
1. Monera (Prokaryotes). Mostly single-celled bacteria.
Thousands of species. No central nucleus. No nervous system at all, but
manifests basic irritability (general avoidance motion) to noxious stimulus.
No reason at all to believe that this little cell experiences 'agony' at
dissolution.
2. Protista (Eukaryotes). Mostly uni-cellular with-nucleus
species (but some colonial forms also). "Some of these organisms are animal-like
(protozoans), others resemble plants (algal protists), and still others
demonstrate the characteristics of fungi." (NS:SOB:377).
Protozoans
(thousands of species) have no recognizable nervous system, but can respond
to various stimuli with chemical changes (e.g., motion can be started by
an external stimulus changing texture of the cytoplasm [NS:BPS:330], not
remotely akin to nerve impulse conduction and response.)
Algal Protists
(over 25k species) are plant-like, with some multi-cellular organisms.
Especially important are the diatoms and dinoflagellates, which produce
3/4th of all organic material in the world! [NS:PSB:196].Fungi-like
protists are basically slime molds. Many of these species reproduce
by fission--the elongation and division of the cell nucleus (if somehow
the 'adult' nucleus was 'sensitive' to pain, what a painful process elongation
and division would be every reproductive cycle of 20 minutes or so!!!).
Again, nothing here to suggest an 'agony-capable' conscious center.
3. Fungi (multi-cellular or multi-nuclear, except yeasts)
They absorb food rather than ingest it (they secrete digestive fluids outside
their bodies and absorb the resulting solution), and are limited in mobility.
Includes yeasts, molds, and mushrooms. Over 100,000 species. No structures
to support an 'experience of agony'.
4. Plantae (plants). These are divided into bryophytes (non-vascular) and tracheophytes (vascular). The non-vascular plants are mosses, liverworts, and hornworts. They lack structures to 'stand up' so they hug the ground. They are photosynthetic, though, and comprise around 18,000 species. The vascular plants are the ones we are most familiar with, with around 260,000 species.
There are three areas of plant irritability that would be closest to 'sensation' or nervous system function: tropisms, triggers in rapid touch-response plants (e.g. Venus Flytrap), and induced responses to herbivory.
"Tropisms are named from the eliciting stimuli and described as 'positive' if growth is toward the eliciting stimulus and 'negative' if growth is directed away from the stimulus...Responses to gravitation (geotropism), water (hydrotropism), light (phototropism), pressure, touch (thigmotropism), etc. are crucial to the survival of a plant.
"The tropisms, as well as a number of other phenomena occurring within
the plant, are probably mediated by plant hormones. A
hormone is
a substance produced in one part of a living organism that has profound
metabolic effects of function and behavior and generally involve relatively
slow responses as compared with the faster neural responses, which are
found only in animals." [NS:SOB:197]
and
"Most animals perceive external stimuli via specialized sense organs
and respond with the aid of an elaborate nervous system. Plants have
neither sense organs nor nervous systems, but react to stimuli by means
of tropisms. A tropism can be defined as a growth movement
effected by an actively growing plant in response to a stimulus coming
from a given direction. This results in the differential growth or elongation
of the plant toward or away from the stimulus." [NS:BPS:282].
(2) The closest we get to a neuronal firing or nerve impulse among plants
might be in the Venus Flytrap and mimosa plant. These show very rapid responses
to touch, but do not use muscle tissue and efferent nerves, of course.
The signal mechanisms are probably electrical traveling down sieve tubes
and altering permeability of plasma membranes, flushing fluids from cells
which creates the movement. These are elaborate mechanical systems, with
loose analogs in some lower vertebrate forms. This is still way too far
from sympathetic nervous systems to be considered even 'pain possible'.
(3) Induced responses to herbivory [NS:IRH] is a relatively new area
of research, which studies what physiological changes occur in a plant
as it is being eaten and/or after it has been eaten (actually, it also
includes a wider range of threats that just herbivory). This fascinating
subject attempts to find signal mechanisms for damaged parts (e.g., leaves)
to send throughout the plant to "induce a response." The basic mechanism
for this involves chemicals in plant cells which are broken loose by chewing.
These chemicals combine with other chemicals in the surrounding plant cells,
creating compounds (e.g., systemin) that are transmitted through the plant,
triggering various responses (like hormones) such as the production of
proteinase inhibitors [NS:IRH:80f], and of increased rates of photosynthesis
[NS:IRH:51]. All of the signaling mechanisms being investigated are chemical
(the responses of plants are too slow for electrical signals to be the
mechanism [NS:IRH:35]), so this response is similar to tropisms, in their
"non-cognitive" status [NS:IRH:12]
5. Animalia (animals). Here we need to get a little finer
detail, because we will begin running into real nervous systems soon. For
simple breakdown purposes:
A. Invertebrates (90% of all animal species are in this): Ranges in organizational complexity from the simple sponges (more colonial in organization than unitary) to 'mid-range' Annelids (worms) to the most complex organism in this class the Insect. In this broad group we begin to see nervous systems, although of simpler and segmented types. The Insects are the dominant group here numerically, comprising over a million species (experts believe that the actual number of species may be 2-4 times that amount). They represent 84% of all living animal species.
Although the squid and octopus are quite well-developed from a nervous system point of view (the octopus is a frequent experimental animal in learning studies), their brains are actually fused ganglia, enabling high levels of coordinated activity/response [NS:AWB:282]. They have many specialized neural developments (on a functional level matching some lower animals) and might be considered to be on a par with the insects in nervous system sophistication. (Some actually put them up higher, with the fishes.) However, the integration of internal sensory data (a requirement for 'suffering') is lacking: "Among other invertebrates, the cephalopod Octopus clearly exhibits proprioceptive abilities, though specific receptors have not yet been identified. These animals, however, seem unable to integrate proprioceptive data in the central nervous system with other sensory information in learning. Thus an octopus readily can be taught to discriminate between two small cylindrical objects (both provided with longitudinal ribs) if the ribs on one of them are somewhat coarser than those on the other. But the animal cannot learn to distinguish between cylinders of the same size if the ribs are equally coarse and if they are longitudinal on one and transverse in the other; nor can it learn to discriminate between small objects of different form or different weight. This indicates that an octopus cannot learn any discrimination that depends on sensory information about the position of the arms and suckers making contact." [EBE:s.v. "Sensory Reception:Invertebrates].
Similarly, the nervous systems of the stinging-cells animals are too specialized to be considered a "conscious" CNS [NS:AWB:111ff]. So, from a generalized brain-complexity standpoint, Insects are still the high-water mark so far in our discussion.
The annelids (e.g., worms) have an elaborate nervous system, but it is massively segmental (like me and my anesthetized arm), and the brain functions as an integration center for a couple of the sensory lines. The stimulus-response system is widely distributed between the brain, the first ventral ganglion, and the segmental ganglia. The brain doesn't seem to have the importance for the worm that we 'need' for agony:
The spider also seems to be without the ability to experience
pain:
"During the act of copulation the male (tn: Australian redback spider, relative to black widow) does a somersault in which he places his abdomen directly over the female's mouthparts. If she decides to eat him, she does so while he is in this position. Significantly, copulation lasts about twice as long if the female is engaged in devouring her mate than if he escapes with his life." [NS:RAL:161]The insects, although the "highest" form in this invertebrate class, are still without adequate nervous systems to experience agony:
Second, we have concrete indications that they do NOT feel internal pain:
This is not altogether unreasonable at all. We know that even humans have tissue that is insensitive to certain types of pain:
Also, the number of nerves in the abdomen of the typical insect is quite
small--most are concentrated on the exterior of the insect.
So, what can we say about the experience of agony here, when an insect suffers tissue damage? Do we have reason to believe that the insect's nervous system 'feels pain'? The above data argues quite strongly that we don't. In spite of the complex behaviors possible, and in spite of the advanced sensing abilities of these species for food detection, the data is still overwhelming that they are either not aware of internal tissue damage, or are not 'agonized' enough by it to initiate action (e.g., stop eating their own abdomen!)
........................................................................................................................................................................
Now, before I get into the more difficult groups (e.g. fishes), let me take stock of where we are:
1. With the possible exceptions of the advanced cephalopods (squid and octopus), all the species we have talked about so far have no 'equipment' with which to experience agony.2. We actually have data that the highest form of life discussed so far does NOT experience pain during massive tissue damage.
3. The above conclusions apply to ALL the plant species (280,000), to virtually ALL the invertebrate species (1,100,000), and to ALL the lower species (140,000).
4. We have yet to discuss the vertebrates, which comprise around 45,000 species (half of which are fishes).
5. So, 1.5M species of life on earth cannot experience agony". This represents 97% of all living species (and, I might add, several orders of magnitude greater number of individuals ( and biomass--a matter we will discuss later).
...................................................................................................................................................
Okay, back to the detail...
B. Vertebrates. We have 45,000 species here to look at with approximate
breakdowns of fishes (20k), amphibians (4.5k), reptiles (6k), birds (8.7k),
and mammals (4k).
At the "high" end, we can be reasonably assured that higher mammals
can experience intense spikes of pain. They certainly have the central
nervous system components, capacity for emotion (CS:WEW, although this
is decidedly a one-sided look), and have various levels of self-awareness
[CS:AM:248ff, but note the criticisms of this approach in NS:AAA:335-339].
[A good example would be animals that limp when a leg is injured. In normal
circumstances (e.g., when they are not trying to trick a predator by acting
injured, as female birds and moose regularly do), this would indicate that
pain was a real experience.]
At the "low" end (i.e., fishes), the data seems to indicate that
fish can experience physiological stress, but the subjective 'pain' experience
of this is quite doubtful. (We also have some specialization/segmental
issues here as well). We will review the data closely, but in addition
to our grave doubts about their experience of agony, it also appears that
the time delay between negative stimulus and the consequent internal 'stress'
symptoms is so great as to make 'sudden death' virtually painless.
[One interesting piece of information here comes from a pet/vet store, specializing in goldfish. They have a web page (http://koivet.com/euthanasia.htm) describing euthanasia for koi goldfish. Look at what they consider to be 'merciful' and 'least painful' ways of terminating the koi:
Let me try to organize this material under the following heads:
1. The gap between the low-end and the high-end of the vertebrates is substantial--fish are quite different than mammals:
"...adult rats subjected to extreme decortification as infants showed no improvement in habit reversal: They became, in effect, like fish in this respect." [X01:FPvol6:225]
"A striking difference between the spinal cord of adult fishes and those of terrestrial vertebrates is the absence of large numbers of proprioceptive [tn: "sensory receptor that responds to physical or chemical stimuli originating from within the organism. In vertebrates, proprioceptors supply the cerebellum with information about the position and movements of body parts."] fibres from muscle spindles. These seem not to be found in fishes." [X01:BF:270] (Notice here, that the main things we need, other than a brain, to be able to know we are hurting inside is a good, detailed set of proprioceptive nerve/fibers. Without these, the brain doesn't get any quick signals.)
"The regenerative capacity of the spinal cord of fish was unparalleled
among the vertebrates. This capacity extended from the simple regrowth
of axons across the lesion to reconstitution of the parenchyma into the
former neural cytoarchitectonics and complete restitution of new nerve
cells and glia." [X01:FPvol4:74f]
"Transection of the entire motor root of the trigeminal nerve resulted in complete paralysis of the jaw. However, within 16 days, mandibular movement had returned to normal." [X01:FPvol4:76]
Cerebellum removal in whole or part (of fishes) sometimes increased response to painful and non-painful stimuli (advanced fishes) and sometimes suppresses it (dogfish). In each case, the functional loss is regained (mostly) in less than a day. [X01:FPvol4:51f]
"Evoked responses induced by acoustic stimulation (clicks) were recorded only from the medulla oblongata and never from other parts of the brain." [X01:FPvol4:56]
"It appears that the caudal neurosecretory system [tn: in the rear of the fish] is a neural center within the spinal cord whose discharge to its endorgan (urophysis) results in the release of substances that regulate the osmotic balance in fish." [X01:FPvol4:72] but "suggests that the center regulating the electrical activity of the caudal neurosecretory system is within the brain proper."[X01:FPvol4:74]
But the vascular system might be under sympathetic (tn: prepares the body for stress) control. [X01:FPvol4:124]
"the CNS is perhaps the most daunting of any other system in the fish, for not only does it contain astonishingly large number of specialised cells in great variety, but the complications of their connections and interactions are great." [X01:BF:264]
"In sharks, destruction of the brain does not immediately cause paralysis, as it does in lampreys and teleosts. Instead, such 'spinal' sharks continue a stereotyped slow swimming pattern for many hours." [X01:BF:268]
If L-DOPA is added to a vat of lamprey spinal cords, they start trying to swim! [X01:BF:268]
"To some extent, the brain can be regarded as an enlarged anterior portion of the spinal cord with hypertrophied centres associated with the development of input from the special sense organs." [X01:BF:271]
So many hard-wired, reflex functions: Mauthner systems (startle response), mesencephalic V (jaw close)...[X01:BF:283-286]
"Autonomic fibres reach almost all parts of the body, and regulate visceral functions to maintain homeostasis." [X01:BF:290]
"The following observations illustrate some of the difficulties in
making judgments of the inner experiences of creatures other than man.
After the spinal cord of a fish has been cut, the front part of the animal
may respond to gentle touch with lively movements, whereas the trunk, the
part behind the incision, remains motionless. A light touch to the back
part elicits slight movements of the body or fins behind the cut, but the
head does not respond. A more intense ("painful") stimulus, however (for
instance, pinching of the tail fin), makes the trunk perform "agonized"
contortions, whereas the front part again remains calm. To attribute pain
sensation to the "painfully" writhing (but neurally isolated) rear end
of a fish would fly in the face of evidence that persons with similarly
severed spinal cords report absolutely no feeling (pain, pressure,
or whatever) below the point at which their cords were cut. [EBE: s.v.
"Sensory Reception: Mechanoreception"] Notice the obvious non-parallel
with humans: in the case of humans with spinal injury, the bottom half
of the body does not 'writhe' under any such circumstances--there is no
'intelligence' in our spinal cords as is in fish.
In the higher fishes, the nerves are parasympathetic and "it is well established that there are no distinct sympathetic nerves innervating the heart directly." [X01:FPvol4:117]
Many functions of internal organ function (i.e., gastric, hepatic, pancreatic secretion) are not under nervous control at all. [X01:FPvol4:119]
"Wilber and Sudak found that there were no compensatory cardiovascular responses to hemorrhage in Mustelus and Squalus." [X01:FPvol4:125]
"The innervation within the longitudinal muscle layer is sparse." [X01:PF:296]
"The hormones themselves (pituitary-adrenocortical) take an appreciable time to increase. Stressed Carassius auratus do not show a rise in serum cortisol [tn: anti-inflammatory chemical] until 10 to 22 minutes after capture. Singley and Chavin showed that when Carassius auratus are acclimated to their environment, no method of capture will affect the serum cortisol levels provided that the time from capture to death is less than 3 minutes. Similarly, neither immobilisation in ice, anesthesia in MS 222 (tricaine methane sulphonate) nor electrical immobilisation affect the level." [X01:CBF:235]
One research study showed a delay period of 40 minutes before a rise in serum cortisol [X01:CBF:236]
"A striking difference between the spinal cord of adult fishes and those of terrestrial vertebrates is the absence of large numbers of proprioceptive [tn: "sensory receptor that responds to physical or chemical stimuli originating from within the organism. In vertebrates, proprioreceptors supply the cerebellum with information about the position and movements of body parts."] fibres from muscle spindles. These seem not to be found in fishes." [X01:BF:270]
One research scientist at AquaNic (http://aquanic.org/) put it this
way: "Pain is transmitted by specific neural pathways and receptors for
pain may be activated by mechanical, thermal, or chemical stimuli. Fish
possess these types of receptors in their skin. In humans, pain is sent
to higher brain centers (prefrontal cortex) where it is perceived and the
perception is associated with a powerful emotional experience.
Fish,
however, do not possess these well developed higher brain centers and thus
they probably perceive a painful stimulus and react to it almost as a reflex.
After the initial perception, they would not be bothered by the stimulus,
similar to what occurs in humans who have had surgery to central brain
regions to treat chronic pain."
5. Fishes are generally r-selected, which means that most fish
die in their infancy (mostly egg and larval stages). Those that survive
this period, generally live relatively long lives. The nervous system of
these high-mortality infant fish is even less developed than that of adult
fish.
The spinal cord of fishes undergoes development during the larval stage. [X01:FPvol4:68ff]
"Although embryonic and larval fish have very large numbers of neurons in the transient Rohon-Beard system, these all disappear at metamorphosis, and are replaced by the sensory neurons of the dorsal root ganglia. [X01:BF:270]
"Locomotor powers of larvae are not great, and prey is detected at one body length or less during early feeding." [X01:BFCB:479]
"Maturation of sensory organ systems aids in detection of predators." [X01:BFCB:480]
2. Young fish experience even less sensation than adult fish.
3. Internal non-reflex responses to stress are quite slow.
The next group up is that of the Amphibian. Although
their CNS "is more like ours" and certainly able to do very, very complex
behaviors, we still have strong evidence that their visceral (tn: internal)
sensory mechanisms are not very pain-sensitive:
And evidence that we still have highly distributed systems at work:
This data seems to indicate that we are still down there with the fish...
........................................................................................................................................................................................
The next group contains the Reptiles. These are cold-blooded
(like the fish and amphibians), but along with the Amphibians, they manifest
a similar situation:
Although brain size arguments can be controversial, in the case of the Reptile the scale difference (in the main associative part for consciousness/sentient experience) is too great for us to expect much consciousness:
The next group contains the Birds. These are warm-blooded
(like mammals).
These are more difficult (theoretically) for me than the others. As warm-blooded, they have to pay more attention to their internal states, their CNS is more developed, and their significantly increased parental care (relative to "simpler" forms) almost encourages 'anthropomorphism'...The strongest evidence I can find for some higher thinking (or experience) comes from the long-term (but apparently still unique) work of Irene Pepperberg and her parrot Alex [see the discussion in CS:AM:171ff].
So, I am going to half-include them in the "spectrum of consciousness" (but with serious reservations).
...................................................................................................................................................................................
Finally, we get to Mammals. It is here that the greatest
controversy occurs. Animal behaviorists/ethologists and naturalists (and
many pet owners!) argue for rather high levels of consciousness and emotion,
whereas those that study comparative neuroanatomy generally shy away from
this.
So, naturalists and zoologists write books like When Elephants Weep--The
Emotional Lives of Animals [CS:WEW], Animal Minds [CS:HI:AM], and
Good
Natured--The Origins of Right and Wrong in Humans in Other Animals
[ PH:GN], describing behavior that is more easily "explained" by anthropopathic
approaches.
And, on the other hand, neuroscientists still point to the major difficulties of assigning consciousness to non-primates (and sometimes primates, as well). Representative evidence and statements are:
and
"We know that there is a great deal of similarity in brain organization across the various vertebrate species. ALL vertebrates have a hind-brain, midbrain, and forebrain, and within each of the three divisions, one can find all of the basic structures and major neural pathways in all animals. At the same time there are obvious differences between the brains of widely different groups of animals. Species differences can involve any brain region or pathway, due to particular brain specializations required for certain species-specific adaptations or to random changes. However, as one follows brain evolution from fish, through amphibians and reptiles, to mammals, and ultimately to humans, the greatest changes appear to have taken place in the forebrain. But evolution should not be thought of as an ascending scale. It is more like a branching tree. The long process of human brain evolution has not just been a matter of making the forebrain bigger and bigger; it has also become more diversified. For example, as we saw in Chapter 4, it was long thought that the neo-cortex was a mammalian specialization, one that did not exist in other classes of animals (the designation "neo" reflects the supposed evolutionary newness of this part of the brain). However, it is now known that all vertebrates have areas of the cortex that correspond with what is called the neo-cortex in mammals--these are just located in a different place in non-mammalian species (birds and reptiles, for example) than in mammals, which caused anatomists to misjudge what these regions are. Nevertheless, there are areas of the human neo-cortex that are apparently not present in the brains of other animals. [CS:TEB:123]
"Throughout this discussion of the evolution of emotion, I've said nothing about what most people consider the most important, in fact, the defining feature of an emotion: the subjective feeling that comes with it. The reason for this is that I believe that the basic building blocks of emotions are neural systems that mediate behavioral interactions with the environment, particularly behaviors that take care of fundamental problems of survival. And while all animals have some version of these survival systems in their brains, I believe that feelings can only occur when a survival system is present in a brain that also has the capacity for consciousness. To the extent that consciousness is a recent (in evolutionary time) development, feelings came after responses in the emotional chicken-and-egg problem. I'm not going to say which animals are conscious (which ones have feelings) and which ones are not (which ones don't have feelings). But I will say that capacity to have feelings is directly tied to the capacity to be consciously aware of one's self and the relation of oneself to the rest of the world. [CS:TEB:125]
And...
"But no matter how firm or flimsy the arguments about consciousness in other humans are, when it comes to making the leap to the minds of other animals, we are on considerably shakier ground. Our ability to hold conversations with other animals is somewhere between not at all and not much. And while our brain is, in many ways, incredibly similar to the brains of other creatures (this is what makes much of brain research possible), it also differs in some important ways. The human brain, most especially the cerebral cortex, is much larger than it should be, given our body size. This alone would give us reason to be cautious about attributing consciousness to other animals. However, there are other facts to take into account. First, as we've seen, the part of the human cortex that has increased in size the most is the prefrontal cortex, which is the part of the brain that has been implicated in working memory, the gateway to consciousness. Some brain scientists believe that this part of the cortex doesn't even exist except in primates. And there is behavioral evidence that only the higher primates, in whom the prefrontal cortex is especially well developed, are self-aware, as determined by their ability to recognize themselves in a mirror. Second, natural language only exists in the human brain. Although the exact nature of the brain specialization involved in making language possible is not fully understood, something changed with the evolution of the human brain to make language happen. Not surprisingly, the development of language has often been said to be the key to human consciousness. Clearly, the human brain is sufficiently different from the brains of other animals to give us reasons for being very cautious about attributing consciousness beyond our species. As a result, the arguments that allow us to say with some degree of confidence that other humans have conscious states do not allow us to insert consciousness into the mental life of most other animals.
"My idea about consciousness in other animals is this. Consciousness is something that happened after the cortex expanded in mammals. It requires the capacity to relate several things at once (for example, the way a stimulus looks, memories of past experiences with that stimulus or related stimuli, a conception of the self as the experiencer). A brain that cannot form these relations, due to the absence of a cortical system that can put all of the information together at the same time, cannot be conscious. Consciousness, so defined, is undoubtedly present in humans. To the extent that other animals have the capacity to hold and manipulate information in a generalized mental workspace, they probably also have the potential capacity to be conscious. This formulation allows the possibility that some other mammals, especially (but not exclusively) some other primates, are conscious. However, in humans, the presence of natural language alters the brain significantly. Often we categorize and label our experiences in linguistic terms, and store the experiences in ways that can be accessed linguistically. Whatever consciousness exists outside of humans is likely to be very different from the kind of consciousness that we have.
"The bottom line is this. Human consciousness is the way it is because
of the way our brain is. Other animals may also be conscious in their own
special way due to the way their brains are. And still others are probably
not conscious at all, again due to the kinds of brains they have. At
the same time, though, consciousness is neither the prerequisite to nor
the same thing as the capacity to think and reason. An animal can solve
lots of problems without being overtly conscious of what it is doing and
why it is doing it. Obviously, consciousness elevates thinking to a new
level, but it isn't the same thing as thinking. [CS:TEB:301-302]
"...How curious and sobering it is to realize that our most advanced
and evolved mental activities depend on unimpaired function of a specific
part of the brain. Another way of putting it, our most human traits exist
for us as a function of the human brain. Further, damage to our frontal
areas could reduce any of us to an almost subhuman level of functioning,
a kind of psychic limbo where we dwell in an eternal present, devoid
of what I consider our most evolved mental ability:
our capacity to
empathize with others. No other creature, including the higher primates,
comforts the injured or the bereaved, because other creatures cannot imaginatively
identify with another. [CS:TMB:106-107, above]
Although there are massive methodological problems with deciding this
issue on the basis of observation and anecdotal data [e.g., NS:AAA] I personally
tend to the side of the ethologists/naturalists here, that there is at
least a spectrum of consciousness adequate to support a spectrum of suffering
[e.g., PH:ATMS:49].
Now, I am not going to try to decide this issue here; for my argument I can agree that mammals can experience stress and suffering. But I also want to point out that IF they can experience suffering, THEN they also can experience pleasure during their lives. Cf:
Indeed, the same endorphins that are used to mute pain, are known to produce
a euphoria in humans when we exercise...If these operate the same in mammals
(as the shared nervous system argument and similar neuropharmacological
arguments run), then endorphins also would (logically) generate feelings
of well-being in animals.
So, where does this leave us?
2. In addition to the 4,000 species of mammals, we might add the 8.6K species of bird, but this is really stretching it.
3. This gives us only 14.6k species (out of 1.55M) that could experience 'agony' at all...a whopping 0.94%...(and consciousness would likely be on a spectrum, with primates being 'high' and birds being 'low')
..........................................................................................................................................................
The next part of the statement we want to look at is that of "death"--all things KILL what they prey on.
To what extent is this true?
This actually is a simpler and shorter question, because the types of
predation are well-known.
(Note that we will not restrict our discussion here to the .94% of the species that could experience agony, but will look at all types of predation-like behavior.)
Let's first survey the situation "trophically", along the stages in the food chain/web...
Let's start with the terrestrial food "chain" (or more accurately, "web"):
2. Then come the herbivores, which eat the primary producers
(plants). There are two main groups here: the insects and the animals.
"Negative effects of insect herbivores on mature plants, though
palpable, are seldom fatal. Herbivory is more often life threatening
for plants attacked at earlier developmental stages."[X01:PAI:143]
"Grazers also attack large numbers of prey, one after the other, during
their lifetime, but they remove only a part of each prey individual rather
than the whole. Their effect on a prey individual, although
typically
harmful, is rarely lethal in the short-term, and certainly never
predictably lethal...[NS:Ecol:313f]
Mammalian grazing has been known to increase plant production in
the Serengeti by 2x [X01:PAI:166-168]
3. Next come the carnivores, broadly speaking. This would include
carnivorous insects and animals.
Now, let's do the aquatic food web...
2. Primary consumers are the herbivores, and these begin very,
very, very small with the zooplankton. Because of the scale difference
between land plants and sea plants, the herbivore base in the seas DO kill
the consumed phytoplankton (by ingestion). [But, of course, the vast majority
of macro-size sea plants that we are familiar with (e.g., sea weed) are
not killed, similarly to land plants].
3. Carnivores of the sea also kill all that they prey
upon, like land carnivores.
[The differences in the mortality of these tiny plants in these situations
arise from the major differences in those ecological situations. The sea
supports an abundance of much smaller life forms than does the land, largely
due to the impact of gravity and the protein-vs-carbohydrate need differences
of the dominant species in each. [X01:SLS:81-82].]
Predators are typically divided into four categories:
2. Grazers. As we have seen above, these do NOT kill their prey.
3. Parasites. This is a "relationship between two species of
plants or animals in which one benefits at the expense of the other, without
killing it" [EBE: s.v. "parasitism"]
(Notice, however, that the larva only kills one host in its lifetime--the
adult does not 'prey' again itself, and sometimes never even eats again,
depending on the reproductive cycle. Many spiders, as opposed to insects,
do continue predation after development.)
From the data above we can see:
1. Plant life (with minute exceptions such as carnivorous plants) does not kill any prey.2. Land herbivores--insect and animal--do not generally kill their "prey" (i.e., plants)
3. Parasites do not kill their prey.
4. Parasitoids kill prey, but in a 'displacement function'. (One living individual displaces another individual, a net of zero-gain, zero-loss.)
Now, let's size this--how many species fall into categories 1-3 above,
so we can see to what extent "all things kill their prey" is accurate.
1. How many plant species are there? 280,000.
2. How many land herbivores are there?
To calculate this we need to find out how many insects, amphibians, reptiles, birds, and mammals are herbivorous.
In the 8 orders containing herbivores, most of the species are herbivorous, and "over 50% of all insect species occur within the orders that contain herbivores" [above data from NS:EOI:8] (Also, many of the species that eat algae, moss, and fungi could be added to this list of non-killers.)
So, for insects, we get something around 50% representation, amounting
to .5M species.
c. Reptiles: "today only a few herbivorous species remain. These include the marine iguana, which feeds on seaweeds, and some turtles and tortoises." [X01:PAI:164]
d. Birds: "many species of birds are herbivorous. " [X01:PAI:164]. The source didn't give any numbers, but using a conservative figure of 33% for the word "many", this would yield 1/3 of 8,700 species, or 2.8K species.
e. Mammals: "Roughly half of the nearly 4000 species of living mammals are primarily herbivorous. Of the 16 orders of terrestrial mammals, one is associated with plant nectar and pollen, two feed mainly on plant seeds, and seven consume mostly vegetative parts." [X01:PAI:163]
So, the "all things live by the death of prey" position seems radically out of kilter with the known world.
............................................................................................................................................................................
Thirdly, we have to now ask the question about "all things" being
"carnivorous" in the sense of active killing of animal life...we have
to see how dependent life forms are on killing other life forms
for food. We have already seen that the vast majority of living things
(in terms of species, individuals, and biomass--by the way!) do not kill
what they prey upon. But now we need to ask how many species do
not "prey" or do not only eat animals that they kill. In other words,
of those that eat things, how many of these live exclusively off killing
their victims?
The energy-cycle has basically the following agents:
1. autotrophs: the plants and bacteria that create organic material (food) from the energy of the sun (i.e., photosynthesis), from chemosynthesis, or from thermal energy from undersea volcanoes.2. heterotrophs: those that must "find" organic material to consume. There are 4 categories of these:
a. predators (which eat what they kill)
b. grazers (like predators, but which do not kill the source of organic material)
c. parasites (which get organic material from a host, without killing it)
d. decomposers (which get organic material from dead plants/animals)
Given this framework, what we need to ask are:
2. How many lifeforms are parasites (not killing was they prey upon)
3. To what extent do carnivores not always eat meat they actively kill
(e.g., act as herbivores or scavengers)?
1. How many lifeforms are decomposers/scavengers (eating things already killed)?
There are essential two categories of these: (1) bacteria and fungi; and (2) detritivores (animal consumers of dead matter).
In the bacteria and fungi, we have at least [NS:Ecol:406]:
In the detritivores, we have at least [NS:Ecol:408, most specie
counts are from NS:DLO or EBE]:
If one also notes that scavengers are present in more orders (i.e.,
18 [NS:EOI:8]) of insects than any other 'dietary preference' (e.g., carnivore,
herbivore), then we can easily assume that the 213K species listed above
would increase to 300k --easily more that the number of species that
"kill their food" (approx: 280k).
2. How many lifeforms are parasites (not killing was they prey upon)
"The okapi, which lives in the tropical forests of central Africa, harbours at least five kinds of worms simultaneously and some of these may be present in numbers of several hundreds. The host does not seem any the worse for this and can feed itself as well as cater for the fauna it contains." [X01:AP:10]
"It appears that many plants and animals may tolerate 'parasites'
without
showing any harmful consequences..." [NS:Ecol:457]
3. To what extent do carnivores not always eat meat they actively kill (e.g., act as herbivores or scavengers)?
What is interesting here is that even the "spectacular" carnivores still
manifest levels of omnivorous behavior at various levels of intensity,
and also manifest considerable scavenger behavior:
"Most species of fishes are predatory, feeding on live animals or parts thereof. But in some habitats, especially in the tropics, 10 to 20 percent of the species present and nearly half of the individuals may depend primarily on plant material for food; and in ocean areas and lakes where soft bottom materials accumulate, there may be detritus feeders...Although we may tend to consider some species as mainly carnivores or herbivores for the purposes of some discussions, they may often tend toward omnivory." [X01:BFCB:429]
"The large decomposers (in the Serengeti) include lions, leopards, hyenas, wild dogs, and jackals, all of which will scavenge and thus act as decomposers at least part of the time. While there is relatively little competition for living prey among these large carnivores, competition for dead prey is another story. Hyenas get about a third of their food that way, lions 10 to 15 percent, leopards 10 to 15 percent, and hunting dogs 3 percent. Lions are the only predators not significantly interfered with by others. But cheetahs, which alone among large Serengeti predators do not add to their diets by scavenging, lose 10 to 12 percent of their prey to hyenas and (occasionally) lions; hunting dogs lose about half their kills to hyenas; and hyenas and leopards are thought to lose 5 percent or more to lions." [X01:MON:252]
But: "Indeed, in Ngorongoro, the traditional relationship between lions and hyaenas was reversed and the lions got most of their food from kills made by the crocutas." [NS:TC:203]
"A second form of adaptability shown by the large predators relates to the sources of food. The majority of large carnivores are prepared to take any food they can get and very few are finicky about whether the meat is fresh or not. Most of them will feed on a carcase, whether it be of an animal that died naturally or the remains of some other predator's kill, and, if superiority in size or in numbers permits, most are prepared to drive the rightful owners off a kill and appropriate it...the is no clear and simple division into true predators and obligate scavengers: the traditional 'scavengers' also kill for themselves and the predators scavenge off each other's kills and even appropriate those of the 'scavengers', whenever the chance arises...widespread tendencies to scavenging and kill-thieving of the modern carnivores" [NS:TC:223-224]
"(In temperate zones) Of small carcasses--of such a size that they may be removed in their entirety by a single scavenger, it has been calculated that crows, foxes, and badgers may take between 75% and 100%, depending on the season...It has been shown that vertebrate scavengers in temperate systems will find all small carcasses within thirty days or so of death." [X01:CDDAW:7]
"But few of the vertebrates found as scavengers feed exclusively on carrion. Most vertebrate scavengers are normally recognized as predators--but are not above accepting carrion should they chance upon it." [X01:CDDAW:30]
"Numerous species of fish, free-swimming molluscs (like squids and octopuses), swimming crustaceans (such as lobsters or shrimps and prawns) feed upon the carrion as it sinks (just as vertebrate scavengers feed on terrestrial carrion)." [X01:CDDAW:58]
"White sharks have been seen feeding on dead whales, but it is unlikely that even the largest individual would be able to kill a large whale on its own, and there is no evidence that they ever hunt cooperatively...Whale carcasses, both floating and submerged, may provide an important food source for white sharks, especially outside of the pinniped breeding season when this resource is unavailable to them." [NS:RAL:69]
"Most members of the order (tn: Carnivora) are in fact meat eaters, although some ursids [tn: bears], procyonids [tn: raccoons and pandas], and canids rely heavily on vegetation, and the giant panda (Ailuropoda melanoleuca) lives almost entirely on bamboo shoots. " [EBE: s.v. "carnivore"]
"Cannibalism (among lions) also occurs, and the corpse of any conspecific killed in a fight is often treated as food: Schaller saw a lioness eating one of her own cubs, killed by a marauding male belong to another pride. The lion has no aversion to carrion and will stay with a kill until it is finished, even if by then it is far from fresh...The lions' habit of appropriating the kills of crocutas has already been mentioned and they will sometimes dispossess a leopard. Lions will also now and then take small prey such as rodents and tortoises and, as rivers dry up, will hook out fish trapped in shallow pools: they will also eat termites when a flight makes them easily available in large numbers and grass and various fruits are eaten now and then." [NS:TC:205f]
"Many of the predatory raptors will also take carrion when the opportunity arises. These include many of the eagles, such as the golden eagle and the bald eagle, birds we usually think of as exclusively predatory." [NS:RAL:124f]
"They (the larger predators) are really to be looked upon as scavengers
without the patience to wait for their meat to die. They cheat the
bacteria who would have got the bodies otherwise." [X01:WBFAR:156]
b. There are many more species (by a factor of 10) that derive life from a host without killing it;
c. Even the most vivid and effective of killers often eat what they
did not kill.
So, the original statement of "ALL", "DEATH", and "AGONIZING" seems way off base:
It would thus seem that the practice of painful predation is not so
ubiquitous at all, and actually constitutes a very minute fraction of the
experience of life on earth.
......................................................................................................................................................................
But let's continue to "size" this problem...
1. We have been talking about species so far, but how many actual
individuals are involved in painful predation?
This basically can be analyzed under two-concepts: the food-pyramid
and energy/ecological efficiency of tropic levels.
The food-pyramid concept is essentially "demographic"--you count the biomass of plants, herbivores, secondary consumers (carnivores), tertiary consumers (super-carnivores) per area and see what the ratios are. Consider the food pyramid of a representative bluegrass field [NS:BPS:134]:
3 Tertiary Consumers
350,000 Secondary Consumers
700,000 Primary Consumers (herbivores)
6,000,000 Producers (plants)
"The total mass of the animals at the top of the food pyramid, the secondary carnivores, is less than the total mass of the animals close to the plant source of food, the herbivores, because these is less energy available to the secondary carnivores. An individual secondary carnivore is usually very large. Large body size is useful to these animals, since it enables them to capture and kill their prey. However, the number of such carnivores is small."
Part of this is related to the "quantum levels" of body size, as well.
"In the wood as elsewhere there are distinctly different sizes, and the little ones are the most common. The same sort of things exists in the sea in even odder form, for in the open sea the really tiny things are plants; the microscopic diatoms and other algae. Ten times bigger than these (give or take a few times) are the animals of the plankton, the copepods and the like. Bigger still are the shrimps and fish that hunt those copepods. Then another jump brings us to herrings, then to sharks, or killer whales. In any one place in the sea, this clumping of like into different sizes is the normal thing.
"In the sea the rarity of the large is also most clearly shown. Great white sharks are extremely rare, and the other kinds of shark are scattered pretty thinly over the seas too. Fish of the herring size are vastly more common than sharks, but, even so, the number that are seen in a casual dive in the sea is seldom immense....The tiny things of woodland and sea are immensely common; bigger things are a whole jump bigger and a whole jump less common; and so on until we reach the largest and rarest animals of all. A like pattern can be found in tropical forests, Irish bogs, or just about anywhere else. It is an extraordinary thing but true that life comes in size-fractions which, for all the blending and exceptions that can be found by careful scrutiny, are remarkably distinct. Animals in the larger sizes are comparatively rare.
"With every jump in size an even mightier loss occurs in numbers"
"All the insects in a woodlot weight many times as much as all the birds;
and all the songbirds, squirrels, and mice combined weight vastly more
than all the foxes, hawks, and owls combined." [X01:WBFAR:18-19,23,24]
The food-pyramid is such, because the ecological efficiency ratios are what they are. The concept and implications for the number of super-carnivores are clear:
"This would be true even if all animals were vegetarian. But they are
not. For flesh eaters, the largest possible supply of food calories they
can obtain is a fraction of the bodies of their plant-eating prey, and
they must use this fraction both to make bodies and as a fuel supply. Moreover
their bodies must be the big active bodies that let them hunt for a living.
If one is higher still on the food chain, an eater of a flesh-eater's flesh,
one has yet a smaller fraction to support even bigger and fiercer bodies.
Which
is why large fierce animals are so astonishingly (or pleasingly?) rare."
[X01:WBFAR:26-27]
"There are four stages in this food chain: plants, herbivores, carnivores,
and secondary carnivores. Each stage can expect to take in energy at about
1/10 the rate of the previous stage; hence the secondary carnivores are
reduced to roughly 1/10 X 1/10 X 1/10 = 1/1000 of the energy taken in by
the plants. Supercarnivores which ate these would be reduced to 1/10th
of this or 1/10,000 of what the plants received, and so on. No wonder
that every few species find it worthwhile to be such a supercarnivore--there
is practically no energy available to them!" [X01:BP:178]
2. "For example, beneath a square yard of Danish pasture, 10 million roundworms, 45,000 small relatives of earthworms, and 48,000 minute insects and mites were counted." [X01:MON:37]
3. "A census of 1/30 of an ounce of soil from a fertile farm has turned up 30,000 protozoa, 50,000 algae, 400,000 fungi, and more than 2.5 million bacteria." [X01:MON:37]
4. One milliliter of sheep dung may contain: 10**11 bacteria (a hundred billion!), 10**6 fungal mycelia, and 10**10 actinomycetales. [X01:CDDAW:45]
In other words, the more numerous and frequent are the deaths
that occur per unit time, the less likely there is ANY 'suffering'
at all.
2. "But what about those 'big fish eating the smaller fish eating the tiny fish'--wouldn't that indicate huge amounts of suffering?
Actually, no.
b. Most fish do NOT eat other fish, but eat the unquestionably non-agony life forms "below" it:
c. Even in the cases of fish eating other fish, these involve actually
much less 'struggle' than one would find on the African plain.
Most
of it is instantaneous, and over in less than a minute (before the
physiological system of the prey fish has time to crank up the visceral
'feeling' hormones, as we saw above).
"Because the majority of fishes engulf and swallow their prey whole, they are not known for complex handling procedures." [X01:FPvol8:100]
"For example, when fish eat insects or small aquatic organisms the
prey is generally captured and swallowed whole..." [X01:EBF:77]
"Although food is collected by the mouth and is sometimes dealt with
by the jaws and their teeth, the real processing, in some cases amounting
to mastication, usually takes place in the throat or pharynx where
flattened pharyngeal bones at the back of the throat is such that all food
must pass between them 'as between a pair of millstones'. The number, size,
and structure of teeth planted on the surface of these bones differ according
to the type of food most commonly processed." [X01:FPvol8:94] Some fishes
even have teeth in the esophagus. [X01:FPvol8:166]
d. Strangely enough, the amount/frequency of predation (per unit of biomass) among fish is considerably less than that of terrestrial mammals.
The reason for this has to do with the 'cold-blooded' nature of fishes (as well as reptiles and amphibians, by the way). They simply do not need as much food as land-based mammals.
"But its (a pet crocodile) low metabolic rates mean that it requires far less food, which is an advantage. I used to feed the caiman a tiny piece of liver once a week, whereas the family cat demanded three meals every day." [NS:RAL:40]
"Once the crocodile has gorged itself on wildebeest, it will go without food for several weeks. In contrast, a similar meal eaten by a lion would last only for a few days. Like other reptiles, crocodiles eat about two or three times their body mass in a year, compared with about twenty times for a lioness." [NS:RAL:44]
"A snake's food requirements are therefore modest, and it consumes only two or three times its body mass in a year." [NS:RAL:52].
"It has been estimated that an adult [Komodo dragon] consumes between three and four times its body mass per year, compared with about thirteen for a male lion and twenty for a lioness." [NS:RAL:55]
"From the body temperature data obtained from the white shark,
the researchers estimated that it had a low metabolic rate, and that a
single meal would last an individual for more than a month. This certainly
makes good sense, and we should dismiss the notion that sharks are forever
on the prowl for something to eat." [NS:RAL:71]
Actually, no. (Even after you filter out the gross anthropomorphism
in the 'tormenting' word!)
Lions do most of their hunting at night. [NS:RAL:11] and most prey suffice for more than one meal [NS:TC:224]
"From the body temperature data obtained from the white shark, the researchers estimated that it had a low metabolic rate, and that a single meal would last an individual for more than a month. This certainly makes good sense, and we should dismiss the notion that sharks are forever on the prowl for something to eat." [NS:RAL:71]
"Such snakes, like pythons, may go for two or three months without feeding..." [NS:RAL:53]
"Crocodiles spend half their time in the water, seldom straying far from the water's edge. Most of their days are spent basking in the sun or lying in the shade..." [NS:RAL:42]
"If the spider is that successful, it will probably not hunt again for
many more days, because spiders have low metabolic rates and correspondingly
low food requirements...Spiders have been known to live for over six
months without eating." [NS:RAL:160]
"The hunting successes of the lion, averaged for all hunts both day and night, varied from 14 percent for reedbuck to 32 percent for wildebeest, so the odds are well in favor of the prey. Hunting dogs and cheetahs did considerably better, with average successes for all prey hunted of 70 percent." [NS:RAL:34]
"Mech also gives the details of the hunting [by wolves] of caribou and mountain sheep. In all cases it appears that the success rate of the wolves is low: many attempts fail for every one that succeeds." [NS:TC:148f]
"Kruuk summarized the results of his extensive observations of hyenas hunting wildebeest calves both individually and in groups. Only about one third of 108 attempts by one or more hyenas to capture calves were successful." [CS:AM:63]
Of a major study done on wolves/moose predation in Isle Royale National Park, wolves only had a 5% success rate, in 120 active pursuits. [NS:TC:148] and in some cases, this has resulted in starvation for wolves [NS:TC:144].
Peregrines have a success rate in the 10-30% range, and falcons around
11% [NS:RAL:111-113]
"He found that the muskrats capable of holding a territory in the most favourable parts of the habitat were virtually immune from predation but that mink and fox levied a heavy toll on the homeless, the transients, the weaker animals forced out to live in sub-optimal habitats and on those suffering from disease or from wounds received in territorial fights with their fellows." [NS:TC:149]
"Kruuk observed that predators whose home area was close to that of territorial tommies never hunted these familiar neighbors. Some hyenas usually rested from midday until late afternoon in dens located within territories of male tommies. When they left their dens in the early evening they were presumably hungry; but, although they were often surrounded by tommies, they passed between them and hunted in other areas. Perhaps the hyenas knew that the local tommies were alert and difficult to catch." [CS:AM:59]
"Mech also gives the details of the hunting [by wolves] of caribou and mountain sheep. In all cases it appears that the success rate of the wolves is low: many attempts fail for every one that succeeds. If this is so, it seems a priori likely that the individuals killed are not a random sample of the prey population but are mainly animals that are in some way inferior to or at a disadvantage as compared with their fellows. Studies of the kills made bear this out: they consist mainly of the young and the aged and those killed as young adults are often injured or diseased." [NS:TC:148f]
"The natural predator is not a random killer, nor does he choose trophy specimens: his selection, based on what he can most easily get, is comparable with that of the stock breeder who eliminates weaklings from his breeding herd..." [NS:TC:149]
"Usually they [the big cats] feed by culling the old, the sick, and
the young." [X01:WBFAR:156]
d. In fact, the data suggests that, for the vast majority of a prey
animal's lifetime, the predator/prey interactions are not "anxiety producing"
at all:
"When Thompson's gazelles detect a predator, they often do not flee but move closer. They appear to be much interested and to be inspecting the dangerous creature. Walther sometimes saw a herd of tommies recognize a predator at 500 to 800 meters and then approach within 100 to 200 meters. Under these circumstances the herd contracted into a smaller area than when feeding, the individuals remaining closer to one another. When the predator moved, the herd followed it, evidently aware of the danger and ready to dash off at the first sign of an actual attack. The predators also seem to understand the situation and rarely attack a group of alert tommies. Predator monitoring by territorial males was especially evident. At the approach of a predator in daytime the females generally moved away, while the buck stayed in his territory and kept the predator under close watch. As it moved he usually followed at a safe distance until it reached the territorial boundary. Then one of the neighboring territorial males would take over the monitoring of the dangerous intruder. This sort of predator monitoring was so effective that predators captured only one of fifty territorial males that Walther studied intensively during a two-year period.
"George Schaller (1972) describes other examples of prey animals monitoring the behavior of predators and not appearing to be frightened unless the predator rushes at them directly. When a lion is walking along steadily, tommies, zebras, wildebeest, and other potential prey usually face the danger in an erect posture but do not run away. Wildebeest usually keep up an incessant grunting, but when a lion approaches they stop, so that the predator is surrounded by a zone of silence, which undoubtedly warns others of the danger. A group of wildebeest may even approach a predator and line up to watch it pass. But if a lion stops and turns in their direction, the grazing animals usually flee for a short distance, then turn and stand watching again. Roughly thirty meters from a lion seems to be considered a safe distance in open country, but when potential prey animals move into thick vegetation they behave much more cautiously. " [CS:AM:57f]
"The most abundant antelopes of East Africa are the Thompson's gazelles,
or tommies, which are preyed upon by many carnivores, including leopards,
lions, cheetahs, hyenas, and wild dogs...Despite the fact that tommies
are an important portion of the diet of several predators, they do not
appear to spend their lives in a constant state of terror...Walther
states that tommies seem less disturbed by predators at a reasonable
distance than by heavy rainstorms." [CS:AM:54]
"There is no doubt that all these big fierce predators have some
effect on the numbers of their prey because they kill the young.
But
they cannot usually kill a very large proportion of the young because the
number of predators is relatively small. The young typically make their
appearance at only one time of the year, and the predators must live the
rest of it too. The numbers of big cats and wolves that a herbivore mother
must look out for in the spring is mercifully low because it will be the
number that has been kept alive through the winter by the supply of old
and sick animals. It thus seems very likely that the larger and fiercer
predators are not nearly so important in regulating the numbers of animals
in nature as common sense suggests. They are really to be looked upon as
scavengers without the patience to wait for their meat to die. They cheat
the bacteria who would have got the bodies otherwise. Two rather pleasing
thoughts come from this discovery. One is that the lives of big game
animals are lived in a large measure of freedom from the awful world of
tooth and claw that we can conjure up by a careless reading of Darwin. Not
only do these animals live in that peaceful coexistence with their neighbors,
which the mathematical ecologists discovered, but they also may live with
less fear of being killed than we had supposed, except as a sort of euthanasia.
The second pleasing thought is that those who like to shoot big game themselves
no longer have a pretext for killing off the wolves and--cats before they
start on the deer." [X01:WBFAR:156]
Well, let's try to see the factors, facts, and the context of this...
a. There are a couple of powerful factors (other than hunger!) that 'encourage' predators to kill their prey as quickly as possible (i.e., with as short a period of pain, and intensity of pain, as possible)
2. The need to "not draw attention" to the event. Except in the case of the lion (and maybe the largest marine predators), a "struggle" replete with cries of prey and noises of movement, virtually "invites" other predators to the scene! It is in the interests of all "sub-lion" predators to dispatch the prey with the minimum struggle (i.e., a quick death) and with the minimum pain (i.e., no loud screams or cries).
3. The need to avoid injury. Predator-prey interactions in the
large-size mammalian world is not a 'sure thing' for the predator. Wolves
that attack moose and lions that attack wildebeest are always at risk of
getting injured by the prey in the confrontation. This applies to group
hunts as well as solitary hunts. A wounded lion or wolf will not be able
to hunt successfully and so will starve. This tends to make the predator
pick on the easiest prey (sick, old, young, inexperienced) and to neutralize
their ability to hurt them (via a retaliatory bite or hoof-kick) by a quick
kill.
The canine "death bite" is the dominant method for the vast majority
of canine kills all over the world. It is used for the vast majority of
smaller cats worldwide, and used by the big cats whenever possible as well.
It is noted among researchers for its "humane" character:
The main exception to this 'neural-based' death (among the mammalian
predators) is with the canids. The wild dogs and hyenas (when hunting prey
larger than themselves and in a group; they use the neck-breaking shake
on smaller prey) use the method of rapid disembowelment. One work describes
this [X01:IK:13-14}:
2. Specialized forms of killing (outside the mammals) generally involve poisons/venoms (such as snakes, cone snails, spiders/parasitoids). Most of these poisons affect some major internal system of the prey (e.g. respiratory, cardiac, muscular) but they invariably also affect nervous system transmission. In other words, they shut the 'feeling' system down, along with whatever other system they are targeting. This minimizes sensation during the death process (for the reasons of the factors above).
These are so effective on nervous systems that humans use derivatives
of these for pain-treatment.
Cobra venom was analgesic in mice, guinea pigs, cats, rabbits. [X01:Brvol8:475]
"Several preparations of cobra venom and other snake venoms are being used in medicine for the treatment of severe pain." [X01:BRvol8:475]
Injection of snake venoms into dogs and monkeys produce electroencephalographic silence within one minute...and "Investigations on conscious rabbits lead to the conclusion that cobra venom contains components acting on cortical and subcortical areas affecting cortical arousal response." ...but some simply shut the spinal cord down (as in cats)...they pass the blood-brain barrier very slowly, so the effect is likely on the spinal cord [X01:BRvol8:476,479]
Cone snails produce a conotoxin that is used commercially for chronic
pain relief (SNX-111, ziconotide, a product of Neurex Corporation)
For example, take this account of the Ichneumon (in the question), given
in NS:RAL:235:
Notice that the host is oblivious to the 'alien' and continues to
grow and develop...it is only at the rupture of the exoskeleton that the
host finally dies. No indication of suffering by the host in the least--indeed,
indications that it simply 'goes about its business'.
(There are non-chemical versions of this as well: "Some predators are
aided in food capture by strong electric organs that stun or immobilize
prey." [X01:BFCB:429] )
3. In aquatic settings, most of the predation (of reasonably higher
forms) is by simple gulp/swallow. This would result in an instantaneous
death (if the various teeth structures were used in swallowing) or in asphyxiation
(3-6 minutes) for the smaller fish forms (remember from the discussion
above, their internal responses of stress would not kick in within this
time frame, and the slowing of the heart rate would move them closer to
a suspended animation status).
4. In aquatic settings, the really high-end killing (e.g., white sharks,
killer whales) is much more bloody (since asphyxiation is rarely an option),
but it is rapid and much more infrequent as well (as we noted above).
With the exception of when killer whales attack a large whale as a group
(similar to big cats attacking an elephant), most attacks on animals result
in death very, very quickly. The sharks tend to bite their prey in half
(to prevent the prey from swimming away), and death occurs by loss of blood
within a couple of minutes. The killer whales generally do the same (e.g.
sea lions, NS:RAL:73ff]).
One well-respected animal welfare expert makes this point [PH:ATMS:115]:
"The death of diseased seals is something that counts against the
welfare of the seals in a way that the death of ageing seals, or
even healthy seals by normal hazards of the sea (the price they pay for
freedom) is not"
2. Relative to life spans: For prey animals in our possible "consciousness"
range, life spans are measured in years and even decades, in the case of
the very large animals. Most lives are spent in simple "good" lives of
daily activities, reproduction, rearing of young, building of habitat.
Apart from disease and accidents, animals do not live with "pain" for very
long, for chronic or severe pain would quickly render them a target for
a quick kill by a predator. What this means is that the suffering of the
end-of-life event is either (1) minute compared to a relatively 'full'
life for an animal; or (2) a merciful ending to some long-term suffering
(cf. The description by the ecologist Colinvaux of this as "euthanasia"
above).
I think this may be a "marketing" issue...
If we zoom out and ask what are the possible types of interactions between
organisms, the 'textbook' list is:
b. Commensalism -- one benefits, one not affected
Which of these are the most pervasive? Mutualism! (but
it is poorly marketed...smile)
"Ecology textbooks have generally underemphasized or even ignored symbionts
and mutualists, yet they compose most of the world's biomass. Almost
all the plants that dominates the world's grasslands, heaths and forests
have roots intimately associated with fungi. The polyps of most corals
contain unicellular algae, many flowering plants depend on insect pollinators
and a very great number of animals carry communities of microorganisms
within their digestive systems...Mutualism are represented in a much
more varied range of species interactions than competition, predation and
parasitism..." [NS:Ecol:482]
6. "But why do they have to be killed anyway? Why not let them die naturally?
In fact, why do they have to die at all?!"
Let's start with the last question first--why do they have to
die at all?
And the basic answer is two-fold: because (1) the individual needs to
return the nutrients they 'borrowed' from the ecosystem, after using them
for years and/or (2) the group needs to not 'hog' all the nutrients through
unlimited growth/reproduction.
The first "fold" of this principle is relatively simple: after an animal or plant has lived a life, using food resources, minerals, and territory, it must return these to the "pool of resources" somehow, for other generations of life to use for growth and diversity.
Let's look at a couple of statements and illustrations of this first:
"Of course, if plants continually 'mined' soil and water for nutrients, these substances would soon be virtually exhausted...and life would nearly ground to a halt. Fortunately, a mechanism for restoring nutrients to soil and water exists. It consists of a little recognized but essential group of organisms known as decomposers. These are mostly obscure creature such as bacteria, fungi, soil insects, and worms. Decomposers make their living by digesting the wastes and dead bodies of other organisms. They break down laboriously created organic molecules into their simple chemical constituents and return them to soil (or water) from which plants can reacquire them." [X01:MON:36f]The second "fold" of this principle has to do with "balance" in nature: all species need to "stay in their niche" and biological constraints on growth (including death) are important to keep the ecosystem healthy."Unlike the energy of solar radiation, nutrients are not in unalterable supply, and the process of locking some into living biomass reduces the supply remaining to the rest of the community. If plants, and their consumers, were not eventually decomposed (tn: requiring death of some type!), the supply of nutrients would become exhausted and life on earth would cease. The activity of heterotrophic (tn: "eats others") organisms is crucial in bringing about nutrient cycling and maintaining productivity." {NS:Ecol:745]
"For photosynthesizers the supply of solar energy can be considered essentially unlimited, but not the supply of inorganic matter. As an example, suppose that we isolated a species of green plant in an otherwise sterile field and allowed its population to grow. If this plant species were a very tall tree, it might consume the entire supply of essential nutrients that its roots could reach in the soil. All chemical elements in the soil that are used by plants would then be incorporated into the tissues of the trees. (This example is not so farfetched as it might seem. In tropical rain forests, the soil often has few useful mineral nutrients, because rain washes very small molecules away. If the trees are removed, one or two seasons of crops will exhaust the few remaining nutrients.)
"At this point growth would stop for lack of materials. When some of the leaves or other tissues died and were broken up into molecules small enough for the roots to absorb, further growth would be possible.
"This would be a very slow process in our sterile field; still undecomposed plant remains have been found in peat and coal deposits of great age, despite evidence of microbial action. In our example, there were no organisms such as boring insects, bacteria, or fungi which normally break up dead plants. Only weathering and physical breakdown of the large molecules would occur. Under these unusual conditions, it is difficult to predict what might happen, but the trees would almost certainly die and fall to the ground because of inevitable accidents, storms, etc. Since decomposition in the sterile field would be relatively much slower than it is in the real world, the field would eventually become a jumble of dead trees, with a few living spindly individuals growing at a rate determined by the rate of supply of inorganic matter released by the physical decomposition of the dead trees.[X01:BP:164-165]
"The rapid decomposition of plant and animal products: leaf litter, animal carrion and dung, ensures the rapid return of resources bound up within them to the ecological system. The efficient release and recycling of this material is clearly a matter of considerable importance." [X01:CDDAW:1]
Let's try to draw out the logic of these (using our
existing
world). A quite simplified version might look like this (the example is
a terrestrial system of woodlands):
Plants draw upon these two resources: sunlight (of which they only use around 1% of the available energy) and inorganic nutrients (which they get from the soil or the top layer of water in aquatic settings). The plants convert this (inorganic) energy into (organic) plant tissue (biomass). If plants did not die, they would soon use up all the inorganic nutrients in the soil. The results would be stunted plants, and no new plants. (See the description of this immediately above).
But most plants lose their leaves each year, and herbivores only eat about 10% of plant tissue (terrestrial systems only). So, the forest floor is brown each year. But the dead leaves are no good to the plants--the plants did a great job of locking the nutrients up into organic compounds, with tough cellulose walls.
So, in order to recycle the nutrients, we need to have at least two things: something to chew the plant matter (in order to break through the strong cell walls) and something to then convert the cell contents back into inorganic nutrients. This first need (breaking up the cell walls) is dependent on physical factors (e.g., trampling by animals) and chewing action by detritivores (e.g., snails, insects). The second need (the conversion) is accomplished by bacteria and fungi.
And immediately, therefore, we need some animals with motion (to move to the site), some animals with chewing and eating parts. And thus we have bacteria, fungi, insects and other small invertebrates. [We also are going to need tons of flying insects to do the pollinating of the plants.]
And we already need a system of predation...rates of reproduction
of the bacteria alone are a problem:
And the system cannot be one-for-one: I cannot have a bacteria predator that is big enough to 'swallow' a bacteria, that only eats ONE bacteria (a one-for-one replacement) or the problem only gets worse! I have to have a predator who eats multiple bacteria, which indicates a need for mobility--to be able to move around to the various bacteria. And the energy costs of motion are quite high--our little predator has to eat a few MORE bacteria to accomplish this task. And we already have a food pyramid--just to keep the plants alive.
But our little bacteria predator will not be able to move around as quickly as the bacteria reproduce (their fast reproduction was part of the problem to begin with), so we will always have enough bacteria to decompose the dead plant tissue, and most bacteria will have 'long, full lives' for a bacterium.
As you can imagine, we will likely have to have a control predator on this first predator, with the same dynamics, and will increased motion ranges. As the pyramid gets taller, the prey gets physically further apart, and the number of 'eatings' diminish quite rapidly. [They also decrease proportionately, since metabolic rate (i.e., the need to eat!) decreases rapidly with body size.]
But why do they have to be killed? Why couldn't we just let them die?
The answer, at the very bottom of the pyramid, is simple:
they wouldn't
die at all!
This will necessitate a higher ratio of predator to prey than perhaps we see higher up in the pyramid. [Remember, we also needed insects for pollination--and we need a way to feed these insects, which is largely through plants as food, which will require more plant growth, requiring more nutrients.]. And, because insects are known for "population outbursts" that vary geographically, we are going to need a highly mobile (and flexible) predator force to help these outbursts not eat all of their resources (and reduce their subsequent survival as a population). And so we get birds...
We could (and do) have 'same type' predators, in which some insects eat/destroy other insects, and this might keep the pyramid shorter. And this basically works...the insectivorous insects and parasitoids are of critical importance in helping insect orders "contain themselves", in the midst of their thriving!
But we know from population studies that the next higher levels of predators
(e.g. vertebrates) do NOT make a meaningful difference in controlling the
population immediately below them--so why do we need these 'fearsome creatures'
with their killing methods (even if the highest levels, mammals preying
upon mammals, are statistically insignificant and generally quite 'humane')?
What good do they do?
Well, there are a couple of major values that they add:
b. they weed out the sick and old from the animal populations, allowing nutrient reuse/recycling to get started
c. they reduce the excess of prey populations, reducing the intraspecific competition and conflict for resources (both within the group and between groups)
d. they increase community biodiversity(!)--consistently, in robust communities with high interspecies competition, they are the catalysts for keeping specie diversity high (or growing), which, by the way, is the major determinant to community stability [X01:BP:158] .
e. they participate with mammalian herbivores in large-distance nutrient transport ("Mammalian herbivores may also expedite the flow of nutrients between habitats. Large mammals in the Serengeti transfer great quantities of nutrients from the understories of tall grass savanna to adjacent open grasslands." [X01:PAI:169]) and their carcasses also move nutrients around.
f. as generalist feeders (in most cases), they exert a 'pruning' influence on local communities. When one food source is more available, they eat that. When a different one becomes more plentiful or more easily caught, they eat that. Carnivores have long been known to "eat what they can get". This is not enough to 'control populations' but it does 'trim and shape the hedges' a little.
g. they also recycle the bound-up nutrients before a dead mammalian
carcass can do damage to the plant ecosystem. In other words, they eat
the meat 'earlier than' the beginning of the decay process (death), minimizing
the effects of carrion 'poisoning'. This has the effect of diverting nutrients
from the decomposer cycle (temporarily, of course) to a living being, and
to reproductive growth. It essentially keeps the caloric ball 'up in the
air' longer, before it has to start the cycle all over again.
(Note: "During its decay, the processes going on inside a carcase have
a marked effect on the soil and vegetation beneath and immediately surrounding
the carrion. Leached materials soak into the soil beneath the corpse and
the normal fauna of the soil is replaced by a carrion characteristic community.
The effect--which may persist for many months--can be detected to a considerable
depth below the carcase and at quite some distance from it. Vegetation
is often killed and the area may take over a year to recolonize. While
these effects have been most studied in temperate areas, a similar situation
has been reported from East Africa: materials soaking from elephant carcases
during decay formed a pool around the carcases and killed all vegetation
beneath them." [X01:CDDAW:20])
But why couldn't these big animals (or all animals, for that matter) be photosynthetic? All of us green-skinned and never having to eat anything?
The answer to that is rather simple:
But why couldn't they be herbivores or insectivores instead of carnivores? They sorta are a little (as we documented above) but we really need them to be carnivores (or at least we need them to be 'selective killers')--if you look at the value list above.
And when they die and become carcasses, they get recycled by a scavenger,
and/or get decomposed by the bacteria and fungi (above) into inorganic
nutrients for some other organism to 'borrow' for its lifetime.
Which brings us to the next question in the question:
but
why can't prey just die naturally, of old age? Why do they have to be actively
killed by a predator?
Strangely enough, this quick death will actually be the most 'humane'.
A couple of observations will bear this out:
2. "Dying naturally" or "of old age" is essentially some type of organ (e.g., heart, lung, liver) or system (e.g., nervous, digestive, vascular) failure. These types of death DO occur (at least they do in captivity), but they are almost always long processes (like disease) as well. Generally it is disease that leads to organ failure anyway, so these two are closely related. The story de Waal gives about the death of the simian who died of heart failure, due to massive internal infections that had gone on for at least three months, with declining affect and vitality, illustrate the point [PH:GN:55f].
["Old age" (senescence) in mammals is accompanied by definite metabolic and vitality reductions, which generally is accompanied by disease.]
The timing of this is interesting. The "active community life" of a
large animal would generally be considered the span of time in which they
could contribute to that community, often simply the reproductive period.
Most of the larger animals that are candidates for "agony" live deep into
their contributory years:
[Also, in the smaller mammals and birds, 'non-predator' deaths apparently
are more common, for the carcasses of these are the object of considerable
field research for those studying the decomposer cycle (e.g. X01:CDDAW)]
In other words, if every animal turned into a carcass (which feeds
bacteria and then plants) instead of a meal (which turns into new
animal pups, individual growth, and animal community development), we would
have the immense logistics problem of how to make sure there was always
a carnivore close by when an animal died--so they would eat the carrion
before it began the decay process.
You can probably appreciate the sheer logistical problem this would
entail (image the linear programming challenge!), and perhaps even visualize
the image of a group of predators-turned-scavengers, just hanging around
(like vultures in the cartoons) waiting for the old zebra to die...And,
since death is not very predictable, unless you precipitate it by predation,
our predators-turned-scavengers (and their families) would go hungry more
often than not--not a very workable scenario, to say the least.
But there is another aspect of "natural death" that we need to consider
before we 'romanticize' it: the length and suffering entailed in most organ
failures. Failure of organ systems, such as kidney, liver, heart, lungs
is generally a long-term affair, involving considerable personal suffering
(and debilitation). A simple glance at any medical resource, describing
the symptoms and duration of these conditions, would quickly convince one
that it is not necessarily less painful than breaking one's spinal cord!
When the ecologist used the word 'euthanasia' (NS:WBFCAR) in describing
the actions of large predators, there is a powerful truth hiding in there,
I suspect...
................................................................................................................
Well, we are the end of the biological detail section. Let me
try to summarize and make a few observations in the process:
2. If these agony-possible creatures could experience suffering (through
the presence of consciousness), this consciousness would likely be on a
spectrum, with primates being 'high' and birds being 'low'. This would
mean that the suffering of a bird or rat would be much lower than that
of a chimp. And this would mean that the higher the rate of predation
(more smaller victims than large), the less the capacity for suffering
to begin with.
3. We found that only 20% of the predatory species actually kill
their prey--mostly the prey survives. This means that "preying to the death"
is a small fraction of the species considered "predatory" (including herbivores).
4. There are more life-forms that eat food killed
by others,
than life-forms that kill what they eat.
5. Parasitism, in which the prey does not die, and of which often
the host is unaware (of the presence of the parasites) is much more
common than "killing predation" (with parasites being as many as half
of all living species).
6. The combination of the scavengers and the parasites--neither of
which kill their food--accounts for well over 2/3 of all species.
7. Even the truly awesome, large predators often eat what they
did NOT kill (i.e., they scavenge), and most tend to omnivory. [Every
calorie of plant tissue "substitutes for" a calorie from meat, reducing
the amount of predation necessary...]
8. There are many more species (by a factor of 10) that derive life
from a host without killing it; than there are predators who
kill.
9. Any possible conscious suffering is more likely to occur higher
up on the food pyramid, where the numbers of actual individuals being killed
will be minute to that below it...In other words, the more numerous
and frequent are the deaths that occur per unit time,
the less likely
there is ANY 'suffering' at all. [For example, the largest number of 'deaths'
might be tiny zooplankton eating tiny phytoplankton, but there is no feeling
or agony there in the least...The more death there is at a trophic level,
the more likely it is completely "painless".]
10. Most healthy individuals in a species are NOT the targets
of predators, contrary to popular opinion.
11. Most predators are unsuccessful, the majority of the time (the
prey escapes).
12. Most large prey animals live full lives anyway: "Whales, elephants,
apes, and other large mammals in the wild... live through 50 percent
or more of their reproductive spans, and a few survive beyond reproductive
age" [EBE: s.v. "Biological Growth and Development: NATURAL HISTORY OF
AGING: Reproduction and aging"]
13. The observational data demonstrates that, for the vast majority of
a prey animal's lifetime, the predator/prey interactions are
not "anxiety
producing" at all.
14. Our current understanding of ecological "niches" leads us to the
conclusion that the vast majority of interspecies relationships are "peaceful
coexistence" (as opposed to constant 'gladiatorial' competition).
15. "the lives of big game animals are lived in a large measure of freedom
from the awful world of tooth and claw that we can conjure up by a careless
reading of Darwin. " [X01:WBFAR:156] It would seem that this 'struggle'
to survive is perhaps less of a struggle and more of an occasional
nuisance
or periodic hassle...
16. There are a couple of powerful factors built into the system
that 'encourage' predators to kill their prey as quickly as possible
(i.e., with as short a period of pain, and as low an intensity of pain,
as possible). These forces are constantly at work, minimizing suffering
in every act of predation.
17. The facts of how death occurs for much/most prey is consistent
with these factors, and in the vast majority of the cases (smaller
mammals and birds) death is instantaneous, and in the higher mammals
most deaths are either instantaneous (spinal) or swift (asphyxiation).
[The exceptions are when animals attack prey larger than themselves in
groups, but the trade-off is more suffering from one prey (yet still measured
in the 5-10 minute range) versus less actual individuals killed.]
18. The quick-death scenario of most predation is much more 'humane'
than long term disease scenarios, and the very similar 'natural death'
process.
19. All of the obvious hypothetical scenarios (e.g., all animals photosynthetic,
all animals herbivores, all predators wait until the prey dies 'naturally')
run into major logistical challenges, energetic system problems, or don't
solve the basic problems anyway.
20. Predation, of the kind actually practiced in nature (i.e., mostly
old/sick victims, merciful killing methods, non-terrorizing effects on
prey life-styles, minimal impact on population size, positive impact on
community life, agony limited to vast minority of prey species, long prey
life spans), is by far and away the most humane way for the prey individual,
and the most practical way to ensure that life continues, grows, diversifies,
and shares the nutrients with each succeeding generation.
It is mind-boggling to see how clever and how 'merciful' this macro-system
actually is: by "restricting" agony-possible species to very high up on
the food pyramid, where the number of deaths are relatively minute and
the manner of death relatively painless, the overall suffering in the
system has been minimized to the extreme--without compromising
the beauty, stability, and awesomeness of biodiversity...even in
a fallen world, which still joyously anticipates an even better one...
So, the original statement of "ALL", "DEATH", and "AGONIZING" is happily
mistaken, and the statement by J.S. Mill seems almost comical at this point
(but I suppose even comedy has some utility...smile). It would thus seem
that the practice of painful predation is not so ubiquitous after all,
and actually constitutes a very minute fraction of the experience of life
on earth. One can give examples of horrible death-events observed in the
wild, and advance anecdotes of animal cruelty, of course, but the overall
pattern is quite, quite clear: painful predation is statistically minute
in the overall scheme of life.
The world of nature seems (from our analysis above) to be wonderfully
characterized by "more good than bad" and vastly so (in keeping with the
general sketch we made of the biblical data)...all creatures have their
roles to play, their start/stop times, their habitats to build/manage,
their ecological community contribution to make, their food to catch, their
relationships to experience, their kids to raise, and then to yield their
resources to the next generation...including me..."There is an appointed
time for everything. And there is a time for every event under heaven—A
time to give birth, and a time to die" (Ecc 3)
"His eye is on the sparrow, and I know He watches me..."
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