This spring the Wildlife Investigations Laboratory assisted with 8 large mammal captures throughout California. Wildlife capture projects are conducted to help biologists and veterinarians assess the health of these herds through biological sampling, to place GPS collars on the animals to monitor movement and help study habitat use, and for translocating animals. A total of 207 animals were captured including 132 deer, 21 pronghorn antelope, 36 elk and 18 bighorn sheep. Below is a small collection of photos from our month in the field.
By Tom Batter, WIL Scientific Aid
WIL Readers, get ready for some nostalgia! We are catching up to social media trends and introducing a new feature to the blog: Throwback Thursday! We would like to share a glimpse of what wildlife management was like in the days of yore through articles, images, and reports from the past.
Today we bring you an article from Outdoor California’s June 1955 issue. And yes, that’s Melvin R. Clover of collapsible Clover trap fame!
Tracking movement patterns of deer and other large mammals is still relevant to contemporary wildlife management. However, modern techniques have evolved along with modern technology. Nowadays a study animal is more likely to be ear-tagged or fastened with a radio or GPS collar for research. You’ll be hard pressed to find any bucks or does dyed for Mardi Gras festivities anymore!
A deer Hair Loss Syndrome (HLS) workshop was hosted by the Wildlife Investigations Lab on Aug. 20-21, 2012. Most of the state’s leading researchers on HLS participated, including 17 wildlife veterinarians, epidemiologists, graduate students, veterinary pathologists and DFG environmental scientists. Participants reviewed current knowledge and status of research, identified priority research needs, and explored feasible management actions to mitigate the effects of HLS.
HLS is a recently described disorder affecting black-tailed deer in the coastal areas of Washington, Oregon and California. Little is known about the cause of the syndrome and its effect on black-tailed deer populations. It is characterized by a severe infestation of an exotic chewing louse (Damalinia sp.), general decline in body condition, hair loss (especially over the thorax, flanks and hindquarters), morbidity, mortality and excessive grooming behavior. It is seen in mostly young deer, especially does, and is most evident in the winter and spring.
In 2009 another exotic louse species, Bovicola tibialis, was identified in California mule deer in Tuolumne County, causing a similar hair loss syndrome. Fallow deer are the natural host for B. tibialis. How this exotic louse species adapted to native deer is unknown.
Dr. Pamela Swift, WIL wildlife veterinarian specializing in deer health, is the lead investigator of a HLS study, Statewide Assessment of Disease and Environmental Factors Affecting Deer Herd Population Demographics and Health, in which heavy metals (e.g., copper and selenium) in the deer are studied and compared to the presence of the exotic louse, and the presence of clinical hair loss. Samples collected from deer in the study are also analyzed and tested for a disease agent which could cause the suppression of the immune system leading to a severe infestation of lice.
An unidentified parasite was recently found in Humboldt County in a black-tailed deer lung. A hunter-harvested deer was discovered to have a multitude of small fluid-filled cysts scattered throughout the lung tissue. It’s suspected to be the intermediate stage of a tapeworm, known as “cysticercosis”, but this is uncertain since Dr. Pam Swift (Wildlife Investigations Lab ) and Dr. Leslie Woods (California Animal Health and Food Safety Lab, UC Davis) have not seen this pathology before. A sample was submitted to the UC Davis lab and the National Veterinary Services Laboratory in Ames, Iowa, for identification. Results will take up to 30 days. Deer can ingest the tapeworm eggs while grazing. Upon hatching, the tapeworm larvae migrate to various tissues and form cysts. Here the cysts remain until the deer is consumed by a carnivore. The cysts eventually develop into an adult tapeworm in the carnivore. The hunter was contacted by the Department of Fish and Game biologist for Humboldt County and instructed not to consume the meat.