Types of populations to manage

Frankham (1986) documents four types of captive populations of interest to zoos. They are summarized in the following groups:

COMMON DISPLAY SPECIES

The goal for these species is to selectively breed for traits adapted to captivity in an effort to establish a tractable, easily managed population. This could include animals that are docile and do not stress easily.

ENDANGERED SPECIES IN CAPTIVITY FOR LONG TERM CONSERVATION

The goal for these species is long-term maintenance of a viable population and the preservation of genetic diversity. Species of this designation require extensive genetic planning and captive management.

The North American gorilla population is one example. In 2002 there were 361 animals in that population, of the 171 potential founders, 111 are represented by living descendants. The population is doing very well, in fact 99% of genetic diversity has been retained.

ENDANGERED SPECIES BEING PROPAGATED FOR RELEASE INTO THE WILD

Reproduction for these species should be maximized for rapid population growth. Also, the captive environment should be as similar as possible to the natural environment in which the species is designated for release. External disruption should be held to an absolute minimum.

The golden lion tamarin population is a classic example. This captive population has been overseen by an international committee since 1981. Nearly all of these animals are owned by the Brazilian government. In 1990, the government of

Zoos that promote breeding programs for rare or endangered animals, such as the giant panda (Ailuropoda melanoleuca), help to defend against the extinction of a species. (Photo by AP Photo/Xinhua, Wu Wei. Reproduced by permission.)

Brazil gave the committee jurisdiction over the management of both the wild and captive populations. Therefore, this committee establishes policy for and manages the wild and captive populations of golden lion tamarins by making recommendations to the Brazilian government. The committee has no implementation authority but the government tends to accept its recommendations. As a result, the captive population supplements the survival of the wild population through reintroduction and management policy.

RARE SPECIES NOT CAPABLE OF SELF-SUSTAINING REPRODUCTION IN CAPTIVITY

Intensive efforts should be made with these species to develop successful husbandry and propagation techniques in order to achieve self-sustaining populations. When this is accomplished, genetic diversity should be maximized in the captive population.

A hamadryas baboon (Papio hamadryas) at the Phoenix Zoo in Phoenix, Arizona. Zoos attempt to educate the public about animals and their habitats. (Photo by G. C. Kelley/Photo Researchers, Inc. Reproduced by permission.)

There are great advances being made in exotic mammal husbandry as of this writing, but much work is still needed. The reproduction and birth of captive elephants is becoming a major priority. Both the African (Loxodonta africana) and the Asian (Elephas maximus) populations are aging and without more success both captive populations could be in trouble. Efforts are currently underway by numerous institutions to produce captive born animals. The silky anteater (Cyclopes di-dactylus) is another animal that does poorly in captivity. The average life span in captivity is approximately thirty days. Their has never been a silky anteater born in captivity. The wild caught animals usually arrive very weak, dehydrated, malnourished, and heavily parasitized. Also, it is unclear if diets used for other species of anteaters in captivity are sufficient for silky anteaters.

0 0

Post a comment