Dean Biggins, Ph.D.
Biography
Dr. Biggins has been interested in grassland ecology since 1981. Within that broad topic his research has involved varied themes, including aspects of behavioral ecology, predator-prey relationships, and ecology of wildlife diseases. Most investigations have been motivated by their application to conservation and recovery of federally listed species. In that context, Dr. Biggins has worked at field study sites from Montana to Chihuahua, Mexico, as well as in Inner Mongolia and the Tibetan Plateau. Research has involved students at various universities (in CA, CO, ID, NM, MI, MO, TX, WY, France, and China). Taxa of interest have been carnivores (e.g., black-footed ferrets, Siberian polecats, badgers, weasels, coyotes, foxes), rodents, arthropods (fleas, ticks), and bacteria (Yersinia pestis). His present research emphasis is on ecology of plague, including its hosts and vectors, concentrating on maintenance of plague and its chronic effects on wildlife populations and ecosystems during inter-epizootic periods.
Recent Accomplishments
Education
- Ph.D., Zoology, Colorado State University, 2000
- M.S., Wildlife Biology, University of Montana, 1975
- B.S., Wildlife Management, Humboldt State University, 1968
Professional Studies/Experience
- Research Wildlife Biologist, U.S. Fish and Wildlife Service, 1976-1993
- Research Wildlife Biologist, National Biological Service, 1993-1996
- Research Wildlife Biologist, U.S. Geological Survey, 1996-present
- Adjunct Faculty, Department of Biology, Colorado State University, 2002-present
Mentorship/Outreach
Professional societies/affiliations/committees/editorial boards
- American Society of Mammalogists, 1989 to present
Honors, awards, recognition, elected offices
1998—Special Recognition Award, Black-footed Ferret Recovery Implementation Team
- 2004—Conservationist of the Year, Denver Zoological Foundation
- 2005—Science Excellence Award of the Year, USGS, Biological Resources Division, Central Region
- 2012—Aldo Leopold Award, American Society of Mammalogists
Scientific/Oral Presentations, Abstracts
Science and Products
Ecology of Wildlife Disease
Some of the biggest challenges facing wildlife today are changes to their environment from both natural and anthropogenic causes. Natural resource managers, planners, policy makers, industry and private landowners must make informed decisions and policies regarding management, conservation, and restoration of species, habitats, and ecosystem function in response to these changes.
Species Conservation
Large scale changes are occurring to our natural landscapes, often resulting in changes to the distribution and abundance of species living within these landscapes. Populations of many species affected by these natural or anthropogenic changes require focused management to ensure their conservation and sometimes recovery from the brink of extinction.
Ecology of Plague
In North America, the flea transmitted plague bacterium (Yersinia pestis) has colonized and altered native animal communities and ecosystems for more than a century. Many species have suffered adverse consequences from plague, perhaps none more than the endangered black-footed ferret. Plague has established within the ranges of all North American prairie dog species, which collectively serve...
Effects of Soil and Colony Age on Flea Densities
Abundance of fleas is thought to drive rates of plague transmission in the wild. In the complex process of plague maintenance and transmission, fleas as vectors are a potentially weak link in the system that can be exploited. To date, exploiting this link has provided the only stand-alone tools that are operationally effective for managing plague in the black-footed ferret/prairie dog...
Grassland Ecology and Conservation
Grasslands are arguably one of the most anthropogenically stressed ecosystems of the western United States. The highly endangered black-footed ferret and prairie dogs epitomize grassland mammals of high conservation concern.
Transmission of plague by small mammals at Badlands National Park
Plague was first detected in the southwest corner of Badlands National Park (BADL), and spread northeastward, reaching the northeast corner in 2011. Multiple prairie dog colonies in BADL and Conata Basin have had population collapses from plague since its arrival in the park. Plague is now common throughout BADL (NPS and USFS, unpublished data), and threatens efforts to preserve and manage the...
Data on deltamethrin resistance in Oropsylla hirsuta fleas from black-tailed prairie dogs in South Dakota, USA, 2014-2015
Data on deltamethrin resistance in Oropsylla hirsuta fleas from black-tailed prairie dogs in Conata Basin, Buffalo Gap National Grassland and Badlands National Park, South Dakota, 2014-2015. Two data files are available, one from "Mortality trials" and another from "recovery trials". The data from "Mortality trials" includes information on bioassays in which fleas were subjec
Occurrence of plague epizootics in colonies of black-tailed prairie dogs, Pawnee National Grassland, Colorado, 1982-2005
Data on the occurrence of plague epizootics in colonies of black-tailed prairie dogs, Pawnee National Grassland, Colorado 1982-2005. Data are derived from annual prairie dog surveys conducted by staff of the Pawnee National Grassland, U.S. Forest Service.
Enzootic plague reduces survival of Mexican woodrats (Neotoma mexicana) in Colorado
Plague is a flea-vectored disease introduced to North America c. 1900. It is lethal to many American mammal species, causes major die-offs (epizootics) in some populations, and may be ecologically disruptive even at lower interepizootic (enzootic) levels of transmission. We sought to determine the effects of enzootic plague on survival of Mexican...
Biggins, Dean E.; Ramakrishnan, Shantini; Rocke, Tonie E.; Williamson, Judy L.; Wimsatt, Jeffrey Flea parasitism and host survival in a plague-relevant system: Theoretical and conservation implications
Plague is a bacterial zoonosis of mammalian hosts and flea vectors. The disease is capable of ravaging rodent populations and transforming ecosystems. Because plague mortality is likely to be predicted by flea parasitism, it is critical to understand vector dynamics. It has been hypothesized that paltry precipitation and reduced vegetative...
Eads, David A.; Abbott, Rachel C.; Biggins, Dean E.; Rocke, Tonie E. Plague in a colony of Gunnison's prairie dogs (Cynomys gunnisoni) despite three years of infusions of burrows with 0.05% deltamethrin to kill fleas
At Valles Caldera National Preserve in New Mexico, US, infusing Gunnison's prairie dog (Cynomys gunnisoni) burrows with an insecticide dust containing 0.05% deltamethrin killed fleas which transmit bubonic plague. The reduction in the number of fleas per prairie dog was significant and dramatic immediately after infusions, with a suggestion that...
Hoogland, John L.; Biggins, Dean E.; Blackford, Nathaniel; Eads, David; Long, Dustin; Rivera Rodriguez, Mariana; Ross, Lauren M.; Tobey, Sarah; White, Emma M. Evolution, natural history, and conservation of black-footed ferrets
No abstract available.
Biggins, Dean E.; Eads, David A. Factors influencing uptake of sylvatic plague vaccine baits by prairie dogs
Sylvatic plague vaccine (SPV) is a virally vectored bait-delivered vaccine expressing Yersinia pestis antigens that can protect prairie dogs (Cynomys spp.) from plague and has potential utility as a management tool. In a large-scale 3-year field trial, SPV-laden baits containing the biomarker rhodamine B (used to determine bait consumption) were...
Abbott, Rachel C.; Russell, Robin E.; Richgels, Katherine; Tripp, Daniel W.; Matchett, Marc R.; Biggins, Dean E.; Rocke, Tonie E. Grooming behaviors of black-tailed prairie dogs are influenced by flea parasitism, conspecifics, and proximity to refuge
Grooming is a common animal behavior that aids in ectoparasite defense. Ectoparasites can stimulate grooming, and natural selection can also favor endogenous mechanisms that evoke periodic bouts of “programmed” grooming to dislodge or kill ectoparasites before they bite or feed. Moreover, grooming can function as a displacement or communication...
Eads, David A.; Biggins, Dean E.; Eads, Samantha L. Paltry past-precipitation: Predisposing prairie dogs to plague?
The plague bacterium Yersinia pestis was introduced to California in 1900 and spread rapidly as a sylvatic disease of mammalian hosts and flea vectors, invading the Great Plains in the United States by the 1930s to 1940s. In grassland ecosystems, plague causes periodic, devastating epizootics in colonies of black-tailed prairie dogs (...
Eads, David; Biggins, Dean E. Sylvatic plague vaccine partially protects prairie dogs (Cynomys spp.) in field trials
Sylvatic plague, caused by Yersinia pestis, frequently afflicts prairie dogs (Cynomys spp.), causing population declines and local extirpations. We tested the effectiveness of bait-delivered sylvatic plague vaccine (SPV) in prairie dog colonies on 29 paired placebo and treatment plots (1–59 ha in size; average 16.9 ha) in 7 western...
Rocke, Tonie E.; Tripp, Daniel W.; Russell, Robin E.; Abbott, Rachel C.; Richgels, Katherine; Matchett, Marc R.; Biggins, Dean E.; Griebel, Randall; Schroeder, Greg; Grassel, Shaun M.; Pipkin, David R.; Cordova, Jennifer; Kavalunas, Adam; Maxfield, Brian; Boulerice, Jesse T.; Miller, Michael W. Plague cycles in two rodent species from China: Dry years might provide context for epizootics in wet years
Plague, a rodent-associated, flea-borne zoonosis, is one of the most notorious diseases in history. Rates of plague transmission can increase when fleas are abundant. Fleas commonly desiccate and die when reared under dry conditions in laboratories, suggesting fleas will be suppressed during droughts in the wild, thus reducing the rate at which...
Eads, David A.; Biggins, Dean E.; Xu, Lei; Liu, Qiyong Droughts may increase susceptibility of prairie dogs to fleas: Incongruity with hypothesized mechanisms of plague cycles in rodents
Plague is a reemerging, rodent-associated zoonosis caused by the flea-borne bacterium Yersinia pestis. As a vector-borne disease, rates of plague transmission may increase when fleas are abundant. Fleas are highly susceptible to desiccation under hot-dry conditions; we posited that their densities decline during droughts. We evaluated this...
Eads, David A.; Biggins, Dean E.; Long, Dustin H.; Gage, Kenneth L.; Antolin, Michael F. Factors that affect parasitism of black-tailed prairie dogs by fleas
Fleas (Insecta: Siphonaptera) are hematophagous ectoparasites that feed on vertebrate hosts. Fleas can reduce the fitness of hosts by interfering with immune responses, disrupting adaptive behaviors, and transmitting pathogens. The negative effects of fleas on hosts are usually most pronounced when fleas attain high densities. In lab studies,...
Eads, David A.; Hoogland, John L. Interactions among American badgers, black-footed ferrets, and prairie dogs in the grasslands of western North America
American badgers (Taxidea taxus) and black-footed ferrets (Mustela nigripes) sometimes occur sympatrically within colonies of prairie dogs (Cynomys spp.) in the grasslands of western North America. From the perspective of a simplified food web, badgers are consumers of ferrets and, to a greater extent, prairie dogs; ferrets are specialized...
Proulx, Gilbert; Do Linh San, Emmanuel; Eads, David A.; Biggins, Dean E.; Grassel, Shaun M.; Livieri, Travis M.; Licht, Daniel S.