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196 Endangered Mammals biodiversity, primarily through monitoring and advisory roles IUCN now has more than 100 specialist groups within the Species Survival Commission SSC, each focused on a particular taxa More than 30 of the specialist groups work on mammals, ranging from multiple orders such as the Afrotheria Specialist Group to individual species such as the Polar Bear Specialist Group SSC specialist groups consist of volunteer scientists and other experts who provide information on their taxa and even lobby governments for conservation and research efforts One method of providing this information is through Status Surveys and Conservation Action Plans that describe trends, threats, and conservation options, which most specialist groups have now published for their particular taxa Protected Areas With human population increasing and unmodified habitat rapidly dwindling, habitat protection and maintenance is certainly the single most important conservation method for the preservation of biodiversity, including mammals Large mammals often live at low densities and over large individual areas A few protected meadows with the appropriate plant species may be enough habitat to maintain a population of butterflies, but an enormous tract of wilderness is necessary to sustain a viable population of tigers or rhinos Sadly, many large mammals, such as rhinos and tigers, are now entirely or mostly found within park boundaries, and it is uncertain whether populations are large enough to maintain themselves in the face of stochastic events and anthropogenic changes Mammals within protected areas often come into conflict with people sharing the land or living on the edges of the protected areas, and poaching may continue to cause declines in mammal populations within protected areas for a variety of social or economic reasons With climate change, there also exists the possibility that protected areas currently designed around maintaining particular types of habitat will have those habitats altered due to changes in temperature or precipitation, reducing their efficacy for certain species A new focus on conservation of threatened mammals on the edges of protected areas faces daunting challenges from multiple use, social, cultural, and economic growth issues However, targeting conservation efforts on the edges of protected areas by engaging local communities may be the only hope for some mammals, as the money and political will to continue creating protected areas is limited Captive Breeding and Reintroduction Captive breeding has become a well-accepted way of managing and increasing populations of critically endangered species New techniques have led to breakthroughs in captive breeding with some species, including the use of extra-specific surrogate mothers and embryo manipulation, including transfer, cryo-preservation, and microsurgical division However, captive breeding has not worked in every case For example, the critically endangered Sumatran rhino (Dicerorhinus sumatrensis) has been bred in captivity only after many years of unsuccessful attempts, and the loss of 32 of the original 40 captive animals A number of captive breeding programs have led to reintroduction efforts for mammals that were extinct in the wild, including wisent (Bison bonasus) in Europe, Arabian oryx (Oryx leucoryx) in Oman, and Pe´re David’s deer (Elaphurus davidianus) in China Other reintroduction programs have attempted to supplement decreasing wild populations; for example, one third of wild golden lion tamarins (Leontopiihecus rosalia) are now from captive-bred stock Perhaps the best-known case of captive breeding and reintroduction of a mammal involves the black-footed ferret (Mustela nigripes) This small carnivore was once common across the North American plains, where it specialized in hunting large, colonial ground squirrels called prairie dogs (Cynomys) Prairie dogs were considered to be pests and competitors with cattle, so an intensive eradication program eventually reduced historic prairie dog range by 98% The black-footed ferret subsequently declined and was thought to be extinct in the wild in the 1970s, although a small number of ferrets still existed in captivity This captive colony suffered from physical problems, perhaps related to inbreeding as well as disease, and the colony died out in 1979, leading to fears that the species had truly gone extinct However, in 1981 a new colony of ferrets was discovered in Wyoming The first six ferrets to be captured for breeding died of canine distemper The remaining wild ferrets were captured and successful captive breeding resulted in their numbers reaching approximately 300, with some released back to the wild However, the program has not been without criticism: Politically motivated decisions and arguments between state, federal, and private organizations have caused numerous problems and may have even jeopardized the success of the project at times Finding suitable prairie dog colonies (both in terms of finding colonies of adequate size and the political difficulty of maintaining large numbers of what many consider to be a ‘‘pest’’ species) for continued reintroduction is yet another roadblock to ferret recovery Another successful and controversial example has been the reintroduction of gray wolves (Canis lupus) into the Rocky Mountain region of the USA in 1995 on Forest Service lands in Central Idaho and in 1996 in the Yellowstone National Park The reintroduced wolf population, numbering more than 1500 in the Northern Rockies of Montana, Wyoming, and Idaho, has had an obvious effect on the ecosystem, causing a decrease in some species (i.e., coyotes, through competition and killing) and an increase in other species (due, at least in part, to an increase in carrion from wolf kills, but also from ripple effects related to changes in elk habitat use and distribution) This reintroduction has not been without controversy, partly stemming from wolf predation on livestock In 2009, during a single attack on a ranch in Montana, wolves killed 122 sheep, surpassing the number of sheep killed by wolves in the entire state in 2008 Other predator reintroduction attempts have not fared so well, however Attempts to reintroduce lynx (Lynx canadensis) in the Adirondacks of New York have failed The decision by French authorities not to augment the population of brown bears reintroduced in the Pyrenees Mountains of France amidst a hostile social context is casting doubt on the longterm viability of the bear population The success of many reintroductions has also been threatened by legal challenges from individuals or organizations opposed to land-use
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