The C.A.S.H. Courier Newsletter
Selected Articles from our
Fall 2011 Issue
Human Hunting Destroys Our Environment
Isn’t hunting part of nature? Don’t animals living in a
natural environment hunt for food? Isn’t it natural for humans also to hunt
to obtain food?
In nature, predation is a healthy and normal relationship
among species. Species that are in a predator-prey relationship have evolved
together in the same ecosystem; both species benefit from that relationship.
Over time, evolving in the same ecosystem, the predator species and the prey
species have developed structural and behavioral adaptations that allow them
to be healthy predators and healthy prey animals.
Just a few examples: Prey species usually are very
fecund; they tend to have large litters and short gestation periods. Rodents
– rats, mice, cavies are typical prey species and are among the most rapidly
reproducing species among mammals. For example, lemmings can have litters of
about six offspring every three weeks. This is nature’s way of assuring that
the species will survive even though many may succumb to predation. Mammals
that have no natural predators reproduce much slower by having small litters
(often one only birth per pregnancy) and long gestation periods. Elephants,
who have no natural predators, typically give birth to one calf after a
22-month gestation period.
The structure of the eye among prey species tends to be
well-suited for peripheral vision; their eyes are on the side of the head
and can be rotated to be alert to a predator approaching from any direction.
Among predators the eyes are in the front of the head; the eyes can focus
stereoscopically to allow the predator to assess the right distance to
overtake its prey. If we look at birds for example, we see these different
eye structures between the raptors such as owls, hawks, and eagles as
contrasted with the passerines, examples of which are sparrows, starlings,
and orioles. As an aside, even though predators tend to have well developed
stereoscopic vision, a well-developed stereoscopic vision is not necessarily
an indication that a species is a predator. For example, many primates have
excellent stereoscopic vision, which they need for brachiating (swinging
from branch to branch in a rain forest).
The ability to move and survive on their own shortly
after birth (precocial) is again markedly more developed among the prey
species than among species that have no predators. The various species have
evolved these adaptations so they can all live and thrive in their
A natural predator will take some of the prey species but
not so many as to endanger eradicating its entire prey base.
Among species that have co-evolved it is estimated that
no predator species takes more than about 10 percent of the population of
its prey base. The success rate for a predator attempting to take a prey
animal is also relatively low; typically it is between 10 and 20 percent.
Predation, in nature, benefits both the predator and the
prey species. The predator species, and incidentally scavenging species, as
well, benefit by having their food needs met by predation. The prey species,
however, also benefits. Since predators are typically only able to capture
the bottom 10 or 20% of the prey animals in terms of general fitness, they
get the slowest, least alert, of that species. Predation removes infected
and diseased individuals, thereby reducing risk of further contagion and
spread of parasites. Predation also removes congenitally weak animals,
preventing them from breeding. This improves the gene pools of the prey
species. The prey species is healthier and genetically improved by having
The entire ecosystem benefits from this kind of
continuing interspecies interaction. This is natural predation and it
promotes biodiversity – it encourages the evolution of variations of species
and subspecies through adaptations of both the predator and the prey
Hunting by humans operates perversely. The kill ratio at
around a hundred feet with a semi-automatic weapon and scope is much greater
than 10% to 20%. The animal, no matter how well adapted to escape natural
predation (healthy, alert, smart, quick, etc.) has virtually no way to
escape death once it is in the cross hairs of a scope mounted on a rifle.
Nature’s adaptive structures and behaviors that have
evolved during millions of years simply count for naught when man is the
Most deer, for example, would not perceive a rifle hunter
as a predator or a source of danger from the distance at which deer can be
shot with a big game rifle (about 200 feet to 400 yards depending on the
terrain). A wolf at that distance, even though detected, would be totally
ignored. Even the much smaller range of bow-hunter (about 50-75 feet) is
barely of concern to deer. Deer may start to keep an eye on a hunter at that
distance, but the evasion instinct doesn’t kick in until it’s too late.
Hunters go after healthy big animals for trophies and
meat. This leaves the diseased and congenitally weak animals to breed
-–thereby degrading the gene pool and spreading disease. The hunted species
becomes a degenerate and runty imitation of the real species that evolved in
the habitat before human hunting.
Hunting by humans has never been akin to natural
predation. Using modern technology makes matters worse, but even hunting by
indigenous people, before the blessings of Western civilization were
bestowed on them, was just as destructive, only at a slower rate. The North
American mammoth, the Patagonian giant sloth, the pygmy hippopotamus, the
elephant bird of Madagascar are just some examples of animals that were
hunted into extinction by indigenous hunters.
To see exactly how hunting is destructive to an
ecosystem, let’s look at a specific game animal. Probably the most widely
hunted animal in North America is one of the common species of deer, the
Let’s consider that a naturally segmented area has
sufficient browse to feed a deer herd of 400 animals. Wildlife biologists
would describe this by saying that the biological carrying capacity of the
area for deer is 400. Nature has adaptations in place to ensure that the
carrying capacity that is appropriate for that species is not exceeded.
What would happen if the deer population increased to
substantially over 400 in one year?
Let’s say that with all normal control adaptations in
place (including natural predators) the herd size reaches 500 healthy
individuals. At the start of the next winter season, several adaptations
would kick in to ensure a smaller amount of fawns the following year. If
deer are hungry (not starving, but not well fed either), the sex drive of
the bucks declines and the frequency of ovulation of the does decreases; the
does become receptive less frequently than they would if plenty of browse is
available. Since the browse is now insufficient to feed all 500 animals, a
portion of the deer population would not reproduce during that season. With
the normal die-off during the winter and the smaller than normal birth
during the spring, the total population would be reduced to less than 500.
Within a few seasons the populations would again
stabilize around the capacity of the territory. If the herd size dropped
substantially below the carrying capacity (say to 300), other natural
adaptations would kick in (for example, does who have lots of browse during
the rut are more likely to have twins or triplets) to bring the population
back up to the normal carrying capacity of 400. Many other adaptations, some
simple and some fairly involved and not yet completely understood, are used
by nature to maintain the population at the carrying capacity.
These adaptations with which the species have evolved are
based on conditions that have been true for millions of years. Human hunting
totally destroys some of these assumed conditions.
Normally, left to their own devices, the sex ratio of
male to female animals is about 50-50. Deer are born about evenly male and
female. Most “sport” or “trophy” hunters prefer to take bucks rather than
does. Almost all state game agencies mandate that during the regular hunting
season only bucks (antlered deer) and no does are shot. Under certain
extreme conditions, where a deer population has been totally mismanaged for
years, “doe permits” are issued in addition to the regular deer tags in a
desperate attempt to mitigate the mess that the agencies have created over
the years. This policy of shooting out bucks distorts the gender ratio of
Let see what happens when that ratio changes from 50-50
ratio to 80-20 –leaving four times as many does as bucks. This is not at all
uncommon. In Texas and the Southwest, in general, years of mismanagement
have pushed the doe to buck ratio as high as 10:1 in some areas.
Let’s look at two herds – one unhunted with the gender
ratio intact at 50/50 and one hunted with the gender ratio skewed to 80/20.
Otherwise everything is the same; both herds live in an area where there is
sufficient browse for 400 animals. Nature’s adaptations that adjust the
population to the browse will now miscalculate and cause an overpopulation
for the hunted herd but leave the unhunted herd stable at 400 animals.
Based on 50-50 ratio, a herd of 400 will consist of 200
bucks and 200 does. Normal browse conditions signal to each doe to give
birth to a single fawn. Assuming a winter die-off of 100 deer, the surviving
herd would consist of 150 bucks and 150 does. Each of the 150 does would
give birth to 150 fawns. The herd size, including the new 150 fawns is now
450. Fawns have about a 2/3 chance of surviving until the next fall because
they are subject to more predation than adult deer; for example, coyotes
will predate on fawns but rarely on fully grown deer. Other mortality rates
are also higher for fawns than adult deer. At the next rut the herd is back
Based on an 80/20 gender ratio, a 100 animal winter
die-off, and normal browse conditions, there will 240 does and 60 bucks in
the surviving herd. The 240 does will give birth to 240 fawns of which 160
will survive. At the next rut the herd size is now 460 instead of 400.
That’s a 15% increase over the normal herd size. If we factor in
additionally that in the hunted herd the multiple birth rate is much higher
(34% as opposed to 18%) and that yearling does will go into estrus — the
rate of increase is even higher as is shown in the table to the right. A few
successive seasons like that and the herd size approaches conditions where
massive, catastrophic starvation and die-offs are inevitable.
Hunting is not the cure but the cause of overpopulation
and starvation. Luke Dommer, the founder of the Committee to Abolish Sport
Hunting, has proposed several times to various state wildlife agencies that
if they are serious about using hunting as a population control tool in
areas where the sex ratio is already badly distorted, they should institute
a doe-only season. (Taking no bucks but only does until the ratio is again
stabilized at 50:50). All agencies have rejected that proposal – thereby
giving up any pretense of ecologically motivated sound wildlife management.
They quite consciously and openly state that they are in business to provide
the maximum number of live targets to hunters each year.
The state wildlife agencies encourage the destruction of
the naturally evolved ecosystem by encouraging human hunting that balloons
the population of the game species at the expense of the non-game species.
Management techniques, in addition to sex-ratio distortion, include removal
of natural predators (e.g. wolves, coyotes, panthers, bears) altering the
natural habitat to provide additional browse for game species and destroying
the habitat of nongame species (e.g. clear-cutting and/or burning areas and
sowing them with oats for deer at the expense of rabbits, voles, various
reptiles and amphibians – and many other non-game species).
The activity of human hunting is not and never has been a
sustainable, mutually beneficial, predator-prey relationship.
Human hunting techniques, even the most primitive ones,
are far too efficient to meet the conditions required of a natural
predator-prey relationship. In modern times, with new technology, the
efficiency becomes totally lopsided so as to cause instant habitat
degeneration. Add to this the conscious mismanagement of habitat to further
degrade and obviate all natural corrective measures.
Using techniques such as sex-ratio distortion, habitat
manipulation, the removal of natural predators and the introduction of
exotic game species destroys biodiversity. The goal is to maximize the
number of targets for human hunting, thereby destroying the naturally
evolved ecosystems and putting them at the brink of total collapse.
The number of animals of game species (native and exotic)
is maximized at the expense of all others. The naturally evolved adaptations
that insure biodiversity are short-circuited.
The way that these ecosystems can recover is to prohibit
human hunting and other forms of destruction of these animals. We should
allow for the unfettered reintroduction and re-immigration of predators
(which is occurring naturally) and stop the feeble attempts at “managing”
the environment. When it comes to managing the environment, our knowledge is
inadequate to do an even passable job. Even given an ethically sound
motivation, which the state agencies now lack, we simply don’t know enough
to do a better job than nature.
Rather than playing God, we’re acting more like the Three
Stooges, when it comes to managing ecosystems. For the sake of life on
earth, we must not allow the hunting and gun-manufacturing lobbies to
continue to dictate wildlife management policies.
Peter Muller Vice President, C.A.S.H. - Committee to Abolish Sport Hunting
Contact: [email protected]
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Letter From the President
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