The San Gorgonio Mountains in Southern California are home to a population of desert bighorn sheep. At least 20 bighorn have died in the past few months. Click on the link below to learn more about what is being done to investigate the causes of the mortality event, and the important collaborative roles played by California Fish and Wildlife field biologists and veterinarians, land owners, California Animal Health and Food Safety Laboratory, and volunteers.
In early August, CDFW personnel rescued a young female black bear near Whiskeytown in Shasta County. The bear had severe burns to all four of her paws as a result of the Carr wildfire. Following her rescue, the 1.5-year-old bear spent just over one month recovering at the Wildlife Investigations Laboratory where she received tilapia fish skin treatments and other therapies to assist with healing. The recovery was deemed successful – all four paws re-epithelialized, regained function, and the bear put on a significant amount of weight – and she was released back into the wild in mid-September. Due to challenges with placing a collar on a still-growing wild animal, the WIL turned to an international company, GPS Collars Ltd., for an alternative tracking device: the EarTraX V2 GPS/GSM/UHF wildlife telemetry ear tag (https://www.gpscollars.co.uk/product-EarTraX-GPS-GSM-UHF-id5). In addition to being less obtrusive than a collar, the solar-powered unit will utilize existing cellular networks to transmit the bear’s location. The data collected will provide CDFW with valuable insight into bear behavior and landscape usage in post-wildfire areas
The Wildlife Investigations Laboratory is working with biologists and wardens throughout California to ramp up Chronic Wasting Disease (CWD) surveillance of deer. CWD is a fatal neurologic disease of deer and elk that has been detected in 25 states, 2 Canadian provinces, South Korea, Norway, and Finland. The disease has never been detected in California, but the best defense is a robust surveillance program, and an informed public. In 2017 effort was focused on collecting samples from hunter-harvested animals in the X-zones along California’s border. In total 100 animals were tested for CWD, and all came back negative. This year CDFW plans to expand surveillance throughout the state. Keep an eye on our CWD page for more information about CWD sampling locations during the 2018 hunt season. If you are planning to hunt out of state this year, be sure to follow the law, NO SKULL or BACKBONE. We also recommend to hunters who take a deer or elk in a CWD positive state to get your animal tested and processed in that state, and not to consume the meat until you have a negative test result.
Click here to view the brochure on CWD.
Andrew Di Salvo, DVM, the inaugural Free-Ranging Wildlife Health Veterinary Resident with the CDFW Wildlife Investigations Laboratory and the UC Davis Karen C. Drayer Wildlife Health Center, shares a photo from each month of his first year…
A doe and her fawn found themselves in need of some assistance in getting out of a canal near the bridge on Hazel Avenue in Rancho Cordova on Monday, December 15. Personnel from Sacramento Metropolitan Fire, Bureau of Reclamation, Kindred Spirits Fawn Rescue, California Fish and Wildlife North Central Region and the Wildlife Investigations Laboratory all contributed their expertise to ensure the best outcome for the deer. The doe and fawn were safely captured and then released at Lake Natoma. Below are pictures of the rescue.
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.
The western pond turtle (Emys marmorata), the only native species of freshwater turtle in California, has been a species of special concern since 1994. Possible causes for declining western pond turtle populations include urbanization and habitat destruction (which often reduces or eliminates basking and nesting sites available near pond
habitat), poor water quality, and reduced survival of young turtles causing the population to be skewed towards aged turtles that don’t reproduce well.
Another challenge to the survival California’s native western pond turtles has been the introduction and spread of non-native red-eared sliders (Trachemys scripta elegans). Red-eared sliders were imported for the live food market and are popular in the pet industry, often resulting in illegal pet release. “Sliders” are larger than pond turtles
and outcompete pond turtles for nesting and basking sites.
It is not known if disease is playing a role in the observed declines of western pond turtles. Additionally, introductions of non-native red-eared sliders into pond turtle habitat might also introduce new pathogens (disease causing agents like viruses, bacteria, fungi, and parasites) or strains of pathogens that western pond turtles had not been previously exposed to.
Absolutely nothing was known about the pathogens western pond turtles are exposed to in California, so Janet Foley, Joy Worth and then Master’s student, Connie Silbernagel from UC Davis School of Veterinary Medicine, Deana Clifford from the CDFW Wildlife Investigations Lab, and Jamie Bettasco from the US Fish and Wildlife Service teamed up to conduct the first assessment of pathogen presence in western pond turtles across the state. The team also tested non-native red-eared sliders at study sites where both species were living to see whether or not red-eared sliders carried different pathogens and whether or not western pond turtles living in the same sites as nonnative sliders were more likely to carry different pathogens.
The team found that both species of turtles carried Mycoplasma spp. bacteria (a cause of respiratory infections) with prevalence being highest at sites in southern California regions. Furthermore native western pond turtles that were infected with Mycoplasma spp bacteria were more likely to weigh less and live in southern California. All turtles tested negative for two common viruses, Herpesviruses and Ranaviruses, and Salmonella bacteria (which can cause gastroenteritis and is a bacteria that can infect people).
This study is the first of its kind to document pathogen prevalence in both native western pond turtles and non-native red-eared sliders and will provide important baseline data as we strive to conserve western pond turtles in California.
Silbernagel C, Clifford DL, Bettaso J, Worth S, Foley J. Prevalence of selected pathogens in western pond turtles and sympatric introduced red-eared sliders in California, USA. Diseases of Aquatic Organisms 107:37-47
Early November 2013 was a busy time for Wildlife Investigations Laboratory staff. Two important disease surveillance projects for bighorn sheep were conducted in the Mojave National Preserve in San Bernardino County and the Peninsular Ranges in San Diego and Imperial Counties. A total of 91 sheep were captured, GPS collared for monitoring and biological samples taken so that a variety of disease tests could be done. One significant test is for Mycoplasma ovipnenumonia, a bacteria that caused a bighorn die-off in the Mojave earlier this year. Scientists will use the laboratory results (still pending) to determine the cause of the disease and to document the number of animals involved and the geographic extent of the outbreak.
These projects could not have been conducted without the many partners involved including; The National Park Service, the Society for the Conservation of Bighorn Sheep, California Wild Sheep Foundation, United States Fish and Wildlife Service, Bureau of Land Management, Oregon State University and Colorado State University.
By Jaime Rudd, WIL Scientific Aid
Spring is a transformative season in California’s Colorado Desert. The mild weather and gentle rains that trickle down during this time of year are what entices the desert flora and fauna to awaken from their dormancy.
Colorful desert flowers come into bloom and sweeten the air as moths, butterflies, bees and other insects bustle about collecting pollen all the while fertilizing each blossom. Various desert reptiles come out from torpor and sprawl upon the sand as the sun’s rays rest upon their backs. The invertebrates and small mammals, when not offering new life of their own, are out collecting seeds and eating the newly arrived vegetation. It is also the time of year when the mild-mannered spring desert welcomes the next generation of desert kit foxes (Vulpes macrotis).
Monogamous in nature, kit foxes form pair-bonds that can be lifelong. During the early stage of pup-rearing and care, the female will hermit herself inside the den. Her mate is busier than usual, setting out to hunt for two, returning to the den with prey.
Once the pups are old enough, they are coaxed from their subterranean shelter under the watchful eye of their parents.
The pups will continue to stay with their parents for the duration of spring and early summer. The later summer months bring with it heat, independence, and all too often difficult life lessons. It is in these later months that the journey into adulthood and harsh desert introductions may end for some.
But for now, the season is young and it is still a time when the desert truly gives life, both day and night.
The Wildlife Investigations Laboratory would like to thank Jose Figueroa & David Elms from our Region 6 CDFW office for the wonderful photos captured by remote camera. Remote cameras have been a useful, non-invasive tool for biologists to detect animal presence and monitor the health and physical condition of these desert dwellers. All the photos featured in this story belong to a single mated pair that is being monitored as part of CDFW’s desert kit fox disease monitoring efforts in Riverside County.
California will be the host of the 2015 Desert Bighorn Council Meeting. The meeting will take place in Borrego Springs, California in April 2015. This biennial meeting brings together wildlife biologists, scientists, administrators, managers, and others interested in the welfare of desert bighorn from the seven western states (Texas, New Mexico, Colorado, Arizona, Nevada, Utah and California) to exchange information, present research and take action on matters pertaining to desert bighorn management.
The Council Chair for the 2015 meeting is Dr. Ben Gonzales, Senior Wildlife Veterinarian at the Wildlife Investigations Lab. The Program Chair is Steve Torres, Environmental Program Manager at the Wildlife Investigations Lab. Mark Jorgensen, former Superintendent of Anza Borrego Desert State Park will serve as Local Arrangements Chair.
For more information of the Desert Bighorn Council, please see: