Dean Biggins, PhD (Former Employee)

By 1973, radio telemetry was regarded as an important potential tool for studying the elusive, nocturnal, and semifossorial black-footed ferret (Mustela nigripes), but fears of using invasive techniques on this highly endangered mammal caused delays. We began radio collaring ferrets in 1981. Use of radio telemetry on ferrets proved to be both challenging and rewarding. We document two...

A successful captive breeding program for highly endangered black-footed ferrets (Mustela nigripes) has resulted in surplus animals that have been released at multiple sites since 1991. Because reproductive output of captive ferrets declines after several years, many adult ferrets must be removed from captive breeding facilities annually to keep total production high. Adults are...

No abstract available.

Black-footed ferrets (Mustela nigripes) are highly dependent on prairie dogs (Cynomys spp.) as prey, and prairie dog colonies are the only known habitats that sustain black-footed ferret populations. An existing model used extensively for evaluating black-footed ferret reintroduction habitat defined complexes by interconnecting colonies with 7-km line segments. Although the 7-km complex...

Several laboratory studies have shown that the ingestion of dietary linoleic (18:2 ??6) acid before winter can promote deep and continuous torpor, whereas excess consumption of ??-linolenic acid (18:3 ??3) can interfere with an animal's ability to reach and maintain low body temperatures during torpor. As mammalian heterotherms obtain linoleic and ??-linolenic acid strictly from the diet...

We observed an attack by a bobcat (Lynx rufus) on a cottontail rabbit (Sylvilagus) that involved stealthy approach by the cat for >1 h, followed by a 12.3-s chase covering 116.0 m for the cat and 128.4 m for the rabbit. During the chase, the route of the cat from starting point to kill site was more direct than the semi-circular route of the rabbit. Stride lengths for the cat and total...

Predation on black-footed ferrets (Mustela nigripes) is a potential problem at reintroduction sites, causing up to 95 percent of the documented mortality of ferrets. Strategies to reduce mortality due to predation can focus on preconditioning ferrets prior to reintroduction and/or managing predators of ferrets. Biologists have tried three general strategies to control predators at...

No abstract available.

We used radio-telemetry data (28,560 positional fixes) collected on 153 black-footed ferrets (Mustela nigripes) to (1) reexamine the assumed obligate relationship of these ferrets to prairie dogs (Cynomys spp.), (2) investigate habitat preferences of ferrets at a small scale (1 year (P = 0.048). Also, preference was stronger for wild-born young ferrets than for young captive-born ferrets...

Several models have been developed to estimate prey requirements and to assess habitat suitability of release sites for the black-footed ferret (Mustela nigripes) (e.g., Stromberg and others, 1983; Powell and others, 1985; Biggins and others, 1993). None of these models, however, addressed possible differences in energetic requirements between sites due to climatic differences within the...

Studies of wild populations of black-footed ferrets (Mustela nigripes) in South Dakota in the 1960s, in Wyoming in the 1980s, and of captive-bred ferrets reintroduced to unoccupied habitat in Wyoming, South Dakota, and Montana in the 1990s contributed to our understanding of ferret behavior and improved techniques to find ferret populations. We chronicle the efforts of private, State...

In the natural environment, hibernating sciurids generally remain dormant during winter and enter numerous deep torpor bouts from the time of first immergence in fall until emergence in spring. In contrast, black-tailed prairie dogs (Cynomys ludovicianus) remain active throughout winter but periodically enter short and shallow bouts of torpor. While investigating body temperature (Tb)...