Book Chapters

The California condor (Gymnogyps californianus) is a member of the vulture family. With a wingspan of about 3 m (9 ft) and weighing about 9 kg (20 lb), it spends much of its time in soaring flight visually seeking dead animals as food. The California condor has always been rare (Wilbur 1978; Pattee and Wilbur 1989). Although probably numbering in the thousands during the Pleistocene...

Information on the size, distribution, and productivity of the California sea otter population is broadly relevant to two federally mandated goals: removing the population’s listing as threatened under the Endangered Species Act (ESA) and obtaining an “optimal sustainable population” under the Marine Mammal Protection Act. Except for the population in central California, sea otters...

Canvasbacks (Aythya valisineria) are unique to North America and are one of our most widely recognized waterfowl species. Unlike other ducks that nest and feed in uplands, diving ducks such as canvasbacks are totally dependent on aquatic habitats throughout their life cycle. Canvasbacks nest in prairie, parkland, subarctic, and Great Basin wetlands; stage during spring and fall on...

Captive propagation, introduction, and translocation (relocation) programs for many animals have been undertaken by federal, state, and private agencies for more than 20 years. These programs help aid the recovery of endangered and threatened species, reestablish lost species, augment declining populations, increase recreational opportunities, reduce nuisance species, and introduce non...

No abstract available.

Abstract not supplied at this time

The U.S. Department of the Interior has investigated the deaths of more than 4,300 bald and golden eagles (Haliaeetus leucocephalus and Aquila chrysaetos) since the early 1960's as part of an ongoing effort to monitor causes of wildlife mortality. The availability of dead eagles for study depends on finding carcasses in fair to good condition and transporting them to the laboratory. Such

No abstract available at this time

As part of the joint United States-Canada efforts to monitor populations of Arctic geese and to provide data necessary to set hunting regulations, scientists have recorded not only goose population levels, but also nesting behavior. MacInnes et al. (1990) analyzed data from four long-term studies of five different Arctic goose populations. These studies documented the date the eggs...

Under the pressure of increasing human populations and expanding demands for food and fiber, native tropical and temperate habitats are becoming more restricted, and populations of many resident and migratory birds are declining. Mist net surveys of 111 forest and agricultural sites in Mexico, Belize, and Guatemala show that some migratory species use a wide variety of habitats during...

Fringe-toed lizards (Uma spp.) inhabit many of the scattered windblown sand deposits of southeastern California, southwestern Arizona, and northwestern Mexico. These lizards have several specialized adaptations: elongated scales on their hind feet ("fringes") for added traction in loose sand, a shovel-shaped head and a lower jaw adapted to aid diving into and moving short distances...

Colonial waterbirds, that is, seabirds (gulls, terns, cormorants, pelicans) and wading birds (herons, egrets, ibises), have attracted the attention of scientists, conservationists, and the public since the turn of the century when plume hunters nearly drove many species to extinction. The first national wildlife refuge at Pelican Island, Florida, was founded to conserve a large nesting...