- Peter Muller - New York State Chairman of the Committee to Abolish Sport Hunting -
Ecology teaches us that there are objective, measurable, quantifiable ways to measure the health of an ecosystem. Biological diversity is one such scientifically recognized indicator.
What is biodiversity? It is a measure of species-richness, or the number of species within a community of organisms. Generally speaking, high biodiversity (a great variety of plants and animals, and not too many of each) is an indicator of a healthy and viable ecosystem while a low biodiversity (few varieties of life forms and hordes of individuals of each species) is an indication the ecosystem is under stress and could collapse.
What effect does hunting -- and its concomitant practice of habitat management -- have on the balance of ecosystems?
Let's start answering this question with some other questions: Isn't hunting part of our nature? Don't animals, living in a natural environment, hunt? So, what's wrong with hunting?
Animals living in a healthy ecosystem are in a state of natural predation. By evolving together in the same ecosystem, both predators and prey have adapted so that they both benefit as a species from that relationship. Predator and prey species have adapted structurally and behaviorally to allow them to be healthy predators or prey animals.
For example, prey species usually tend to have very large litters and shorter gestation periods. Rodents such as mice, rats and guinea pigs are typically prey species and are among the most rapidly reproducing species of mammals. Lemmings, another prey animal, can have litters of about six offspring every three weeks. This is nature's way of assuring the species will survive even though many succumb to predation. Elephants, with no natural predator, typically give birth to one calf after a 22-month gestation period.
The eye structures among prey species tend to be well suited for peripheral vision -- their eyes are on the side of the head can rotate to be alert to a predator approaching from any direction. Among predators, the eyes are in front of the head and can be focussed stereoscopically to allow the predator to assess the right distance to take its prey. If we look at birds, for example, we see different eye structures among the raptors (owls, hawks, eagles) as contrasted to passerines (sparrows, starlings, orioles).
The ability to move and survive on their own shortly after birth (precocial) is 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 an ecosystem.
The natural predator will take some of the prey species but will never get close to totally eradicating them. Among species that have evolved together, no predator species ever takes more than about 10 percent of its prey base.
How likely will any individual predator successfully kill its prey in any given attempt? Usually about one chance in five, because the typical rate is around 20 percent -- however it sometimes is less than 10 percent.
Natural predation benefits both the predator and prey species (and incidentally, the scavengers). Predators obviously gain a source of nourishment but the prey species also benefit. Predation usually removes infected and diseased individuals, thus checking the spread of illness, and congenitally weak animals, which prevents them from breeding and improves the gene pool.
Hunting by humans operates in the opposite direction. The kill ratio at a couple-hundred feet with a semi-automatic weapon and scope is virtually 100 percent. The animal, no matter how well adapted to escape natural predation (healthy, smart, alert, quick, etc.), has virtually no way to escape being killed once it is in the cross-hairs of a scope mounted on a rifle. Nature's adaptive structures and behaviors that have evolved over millions of years are almost useless when man is the hunter.
Hunters generally go after healthy, big animals for meat and trophies. This leaves the diseased and congenitally weak animal to breed -- thereby degrading the gene pool and spreading disease.
Hunting by humans has never been akin to natural predation, and modern technology makes the matter worse. But even hunting by indigenous people, before the blessings of Western civilization, was just as destructive -- only at a slower rate. The North American Mammoth and the Pantagonian Giant Sloth are just two examples of animals that were hunted into extinction by indigenous hunters.
To see how destructive hunting can be to an ecosystem, let's look at a specific game animal. Perhaps the most widely hunted animal in North America is one of the common species of deer (white-tailed, mule-deer or black-tailed, with an aggregate of about 50 sub-species).Territories have a natural carrying capacity for each species that has evolved in that habitat. Nature has mechanisms to assure that the appropriate carrying capacity for each species is not exceeded. Let's assume a naturally segmented area has sufficient browse to feed a deer population of 400 animals. What would happen if the net increase of one year brought the population well over 400?
Let's say with all normal control mechanisms in place (such as natural predators), the population reaches 500 healthy individuals. At the start of the next rutting season, several mechanisms would kick in to assure fewer fawns the following year. If deer are hungry (not starving, but not well-fed, either) the sexual drive of the male deer declines and the female deer stop ovulating. Because the browse is not sufficient to feed all of the 500 animals, a portion of the deer population would not reproduce during that season. With the normal die-off during the winter and the lower-than-normal birth rate during the spring, the total population would be reduced to less than 500. Within a few seasons, the population would again stabilize around the capacity for the territory.
If the population drops substantially below the carrying capacity (say around 300), similar natural mechanisms would bring the population back up to the normal carrying capacity of 400. Other mechanisms, such as immigration and emigration, stop help maintain the population at the carrying capacity.
These mechanisms with which the species has evolved have intrinsic assumptions that have been true for millions of years. Human hunting destroys some of them. Normally the sex ratio of male to female animals is 50:50. Deer are born about evenly male and female. Most "sport" or "trophy" hunters prefer to take bucks rather than does. This alters the gender ratio of the population.
Let's say it changes from 50:50 to 75:25 -- leaving three times as many does as bucks. Nature's mechanisms that adjust the population to the food supply will now miscalculate and cause an overpopulation. The same 400-animal herd which would have produced a 100-animal net gain (assuming a 100-animal winter die-off and a 200-fawn increase based on a 50:50 ratio), will now produce a 200-animal increase. (This assumes the same 100-animal die-off, but 300 does give birth to 300 fawns).
With the ratio distorted to 75:25, the population would thus increase to 600 instead of 500. Now indeed catastrophic starvation and die-backs can occur. Hunting is thus not the cure -- but rather the cause -- of overpopulation and starvation of deer.
State agencies encourage the destruction of the naturally evolved ecosystem by encouraging hunting, which balloons the population of the game species at the expense of non-game animals. Other "management" techniques, in addition to sex-ratio distortion, include:
• Removal of natural predators (such as wolves, coyotes, panthers, bears)
• Altering the natural habitat to provide additional browse for game species and destroying the habitat of the non-game species, (i.e. clear-cutting and/or burning areas and sowing them with oats for deer at the expense of rabbits, voles, various reptiles and amphibians, etc.)
• Introducing exotic game species into areas and then destroying the habitat to favor their survival at the expense of native species that have evolved in the area (i.e. stocking an area with pheasants -- an Asian bird -- and cutting tall timber trees needed by raptors for perches).
Hunting by humans is not 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.
With modern technology, the efficiency becomes totally lop-sided so as to cause instant habitat degeneration. Add to this the conscious mismanagement of habitat to further degrade and obviate all natural corrective measures.
Biodiversity is destroyed by using techniques such as sex-ratio distortion, habitat manipulation, removal of natural predators and introduction of exotic game species. The goal is to maximize the number of targets for humans to hunt, thereby destroying the naturally evolved ecosystems and putting them at the brink of total collapse.
What will it take for these ecosystems to survive? Prohibit hunting by humans and other forms of non-sustainable consumptive uses of these animals. Permit the reintroduction of re-immigration of predators (which is naturally occurring). Stop "managing" the environment of those areas.
When it comes to managing the environment, our knowledge is inadequate to do an even passable job. Even given an ethically sound motivation -- which can't be said of most governmental agencies now -- we simply don't know enough to do a better job than nature. For the sake of life on earth, we must not allow the hunting and gun-manufacturing lobbies to continue to dictate wildlife policies.
The above article is reprinted, with kind permission, from Vegetarian Voice (Perspectives on healthy, ecological and compassionate living), Vol. 19, No. 2. Vegetarian Voice is published by North American Vegetarian Society, P.O. Box 72, Doldgeville, NY 13329. Besides publishing above quarterly, NAVS is also the originator of the "World Vegetarian Day" on October 1, in honor of Mahatma Gandhi, that started in 1975. They also celebrate Summerfest every year. For more information, please call them at 518-568-7970.