Growing Up Kit Fox

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.

California's Colorado Desert. This desert is a subdivision of the larger Sonoran Desert that encompasses Arizona, southeastern California, most of the Baja California peninsula, the islands of the Gulf of California, and much of the state of Sonora, Mexico. Map image courtesy of http://www.grabovrat.com.

California’s Colorado Desert. This desert is a subdivision of the larger Sonoran Desert that encompasses Arizona, southeastern California, most of the Baja California peninsula, the islands of the Gulf of California, and much of the state of Sonora, Mexico. Map image courtesy of http://www.grabovrat.com. Inset photo courtesy of Jaime Rudd.

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).

A mated pair of desert kit foxes. The male (top photo), stretches after a night of hunting for both his mate (bottom photo) and himself. These foxes both serve as disease sentinels in the California Department of Fish & Wildlife's (CDFW) desert kit fox disease monitoring project. Each fox is equipped with a radio collar that emits a unique frequency allowing biologists to monitor their survival after an outbreak of canine distemper virus (CDV) occurred in this desert valley the year before.

A mated pair of desert kit foxes. The male (top photo), stretches after a night of hunting for both his mate (bottom photo) and himself. These foxes both serve as disease sentinels in the California Department of Fish & Wildlife’s (CDFW) desert kit fox disease monitoring project. Each fox is equipped with a radio collar that emits a unique frequency allowing biologists to monitor their survival after an outbreak of canine distemper virus (CDV) occurred in this desert valley the year before. Photo courtesy of CDFW, Region 6.

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.

This female desert kit fox keeps a close eye on her den. She has 4 pups that her and her mate have been diligently been providing for.

This female desert kit fox keeps a close eye on her den. She has 4 pups that her and her mate have been diligently been providing for. Photo courtesy of CDFW, Region 6.

Once the pups are old enough, they are coaxed from their subterranean shelter under the watchful eye of their parents.

Already a couple of months old, the pups begin to explore a bit more while their parents remain close by.

Already a couple of months old, the pups begin to explore a bit more while their parents remain close by. Photo courtesy of CDFW, Region 6.

At nearly 3 months old, these pups are gaining more independence. While neither parent is seen in the photograph, they remain nearby.

At nearly 3 months old, these pups are gaining more independence. While neither parent is seen in the photograph, they remain nearby. Photo courtesy of CDFW, Region 6.

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.

Remote cameras captured these images of a bobcat (Lynx rufus, top photo) and a coyote (Canis latrans, bottom photo) passing through a desert kit fox den complex.

Remote cameras captured these images of a bobcat (Lynx rufus, top photo) and a coyote (Canis latrans, bottom photo) passing through a desert kit fox den complex. Photo courtesy of CDFW, Region 6.

But for now, the season is young and it is still a time when the desert truly gives life, both day and night.

This male desert kit fox looks over his 4 pups on a cool desert evening. Sunset is one of the most active times for desert kit foxes as the adults prepare to leave their den complexes (and their young) for an evening hunt.

This male desert kit fox looks over his 4 pups on a cool desert evening. Sunset is one of the most active times for desert kit foxes as the adults prepare to leave their den complexes (and their young) for an evening hunt. Photo courtesy of CDFW, Region 6.

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.

Catch & Release: When to Decide if Medical Intervention is Needed During Wildlife Captures

By Jaime Rudd, WIL Scientific Aid

The Living Desert Zoo publishes an online magazine, FoxPaws. In article 7, issue 2 the zoo writes about an injured desert kit fox that WIL brought into their care last winter.

The Living Desert Zoo publishes an online magazine, FoxPaws. In article 7, issue 2 the zoo writes about an injured desert kit fox that WIL brought into their care last winter.

Studying wildlife on nature’s terms can be difficult. Not only can the weather and topography be uncooperative, but the study species can pose challenges as well. One challenge is deciding if intervention is necessary and appropriate if an animal is found sick or injured.

Here at the Wildlife Investigations Laboratory (WIL), we have veterinarians who can help make decisions regarding wild animal care. Deana Clifford, WIL’s non-game veterinarian, is also an epidemiologist and field biologist. With her diverse background in field studies and wildlife medicine, she is able to make important decisions while in the field or here at WIL. However, like many field biologists, she finds herself in remote areas far from home. In these situations, we rely upon local wildlife rehabilitation facilities for their time and care.

The Tennity Wildlife Hospital and Conservation Center at the Living Desert Zoo in Palm Desert has partnered with WIL to provide medical treatment for sick or injured desert kit foxes (Vulpes macrotis). The desert kit fox disease monitoring project is ongoing and began in January of 2012 in response to a canine distemper outbreak that occurred at a solar development site in eastern Riverside County. During our January 2012 capture effort, an adult male desert kit fox was suspected to have a broken jaw. The decision for intervention was made by Dr. Clifford, who quickly weighed many factors to decide if the risk associated with temporarily taking this fox out of the wild was mitigated by the benefit that would be gained from treatment.  Key considerations for her decision making included: Was the injury significant enough to affect the fox’s chance of continued survival? Could the cause of the injury be associated with our trapping efforts? Could the injury be fixed allowing the fox to return to normal?

Since this injury could definitely affect the fox’s ability to catch prey and potentially was repairable, we transported the fox to the Living Desert Zoo to confirm whether or not the jaw was broken, and if so, examine options for repair.  Living Desert veterinarian Dr. Kevin Leiske consulted Dr. Yee, a veterinary dentist at Veterinary Dental Specialists, and a treatment plan was set up to care for the young male with the intent to release him back into the wild. After approximately 7 weeks of care, the fox’s jaw had healed. Before release, zoo staff made sure that the fox was able hunt and eat whole prey. In March 2012 he was fitted with a radio collar and then taken back to the site where he was originally captured (under state department regulations, all wild mammals must be released within 3 miles of where they were found).

Not long after release, the fox’s collar went “off-air” and biologists were unable to track him. Despite an extensive ground search by California Department of Fish and Wildlife (CDFW, formerly Fish and Game),  biological monitors at the solar site, the Bureau of Land Management (BLM), and volunteers, we did not find the fox. In October 2012, CDFW took to the sky to listen for his signal, but again was unable to successfully locate this one fox.

In January 2013, our concerns were finally laid to rest when we recaptured this male fox! His jaw is a little bit crooked but he was in good body condition and weight — clearly surviving and doing well back in the wild. We also discovered that his collar had simply malfunctioned and was no longer working.  We then removed the collar and sent this fox back on his way to continue thriving in the wild.

After WIL biologists discovered that the radio collar on this desert kit fox was no longer working, it was removed. Upon his release, he shows his gratitude by offering a unique photo opportunity as he rolls around! Photo courtesy of Deana Clifford.

After WIL biologists discovered that the radio collar on this desert kit fox was no longer working, it was removed. Upon his release, he offered a unique photo opportunity as he rolled around on the sand – not far from biologists! Photo courtesy of Deana Clifford.

There is always a risk when an animal has to be removed from the wild, even if it’s just for a few hours or days. Biologists understand this risk and must consider the benefits, if any, to the animal. Knowing the life-history and behavior of the study species is extremely important during the decision-making process.  In this case, a young otherwise healthy male desert kit fox was found to have a potentially life-threatening injury that could be treated with minimal human contact. If we treated his injury and successfully healed the fracture, we felt that his probability of survival was much greater than if we knowingly released him with a broken jaw.

A healed and healthy desert kit fox was recaptured a year after he was found with a broken jaw. While his lower canines protrude a bit, he was in good weight and body condition. Photo courtesy of Deana Clifford.

A healed and healthy desert kit fox was recaptured this winter, one year after he was found with a broken jaw. Trained wildlife biologists are able to use physical restraint rather than chemical immobilization during desert kit fox physical exams. This allows us to quickly conduct exams and take samples without the use of drugs. In this photo CDFW volunteer biologist Teri Baker gently holds the fox while WIL veterinarian Deana Clifford  documents his uniquely new physical feature – slightly protruding lower canines.  This male fox was found to be in good weight and physical condition at the time of recapture. Photo courtesy of Deana Clifford.

WIL would like to sincerely thank Dr. Kevin Leiske, Saldy Portacio, and the rest of the wonderful staff at Living Desert Zoo for generously giving their time and providing care  to the desert kit foxes and other desert wildlife. To read more about how the Living Desert cared for this desert kit fox, go to page 4 of FoxPaws Magazine.

PLEASE NOTE: Only state and federally permitted individuals or organizations can lawfully rehabilitate wildlife. California Code of Regulations section 679 specifically addresses wildlife rehabilitation and has incorporated The Minimum Standards for Wildlife Rehabilitation written by the International Wildlife Rehabilitation Council (IWRC) and the National Wildlife Rehabilitators Association (NWRA). To learn more about the permitting process, please follow the link.

Wildlife rehabilitation is a broad and complex field and it is continually evolving and progressing. Continued education is a critical factor when it comes to maintaining a professional knowledge-base at rehabilitation facilities. Because of this, the CDFW requires that all wildlife rehabilitation personnel (professional and volunteer) satisfactorily complete one approved wildlife rehabilitation training session each year. The minimum for these sessions is 2 hours.

Click here for more information on wildlife welfare and rehabilitation and for a complete list of wildlife rehabilitation facilities in California.

Taking to the Air to Find Foxes that Live Underground

By Jaime Rudd, WIL Scientific Aid

A collared desert kit fox just released after receiving a health exam. Photo courtesy of Deana Clifford.

Working in California’s Colorado Desert can be a challenge, especially during the summer. Daytime temperatures can average over 115°F, and the evenings seldom provide relief from the heat. Another characteristic of this low Sonoran desert is that it typically rains during both winter and summer months. The summer rains are monsoonal in nature, sometimes creating severe flash floods. Luckily, the desert flora and fauna have developed physiological and behavioral adaptations that allow them to tolerate and thrive in such an unforgiving landscape. Because these adaptations are specific to desert living, many of these plants and animals are endemic, meaning they occur only in a certain area and no where else in the world.

One such Colorado Desert dweller we have in California is the desert kit fox (Vulpes macrotis).  Desert kit foxes are equipped with large ears and long limbs for easy heat dissipation and have developed several behavioral adaptations to tolerate desert climates. One adaptation is crepuscular activity during the hot summer months. Crepuscular animals are most active at sunrise and sunset–the coolest parts of the day. Another behavioral adaptation is burrowing and den building and many desert vertebrates and invertebrates are borrow-dwelling animals.

Look at those temps! A remote camera photographs a radio collared fox in California’s Chuckwalla Valley – part of the Colorado Desert. Here, this fox appears to be entering her den to avoid the 107ºF afternoon. Photo courtesy of David Elms from our Region 6 DFG office.

Kit fox burrows, or dens, can be extremely complex with more than 15 openings that wind and turn in various directions and can be more than six feet deep!  Other dens can be simpler and may just consist of one or two entrances. Kit foxes often build multiple den complexes throughout their home ranges, and will occupy them during various portions of the year. Biologists are still trying to understand when and why kit foxes chose certain areas to create dens, but one thing is for certain, kit foxes display fidelity to the sites they choose for den building. That is, they will continuously return to dens in their home range year after year, or at least visit them periodically to make sure no one else has moved in.

Wildlife biologist and veterinarian, Deana Clifford, listens for collared desert kit foxes using a hand-held antenna (also known as a “yagi”). The antenna is connected to a small, receiver that picks up the unique frequencies assigned to each collar transmitter. Photo courtesy of Jaime Rudd.

For the past year, Deana Clifford, the WIL’s wildlife veterinarian for non-game threatened and endangered species, has been investigating an outbreak of canine distemper virus occurring in desert kit foxes along the I-10 corridor of eastern Riverside County. Since the project began in January 2012, biologists have been monitoring the collared foxes using radio telemetry – a sort of biological hide-and-seek. Typically, biologists can find collared individuals by listening to the unique frequency each collar transmits. The collars our kit foxes are wearing have two settings: active and mortality. A mortality pulses at a faster rate than a normal signal if the animal has not moved for many hours. This allows biologists to locate and retrieve the fox carcass and determine the cause of death in a timely manner. In addition to radio-collars, remote cameras have been placed at kit fox dens allowing biologists to monitor their health and physical condition.

Throughout this past summer, thunderstorms surged through the Colorado Desert, resulting in flash flooding. While it is true that this is not atypical of the desert (as mentioned earlier), it can still cause some disruptions to an animal’s regular pattern of activity. Burrowing animals are especially vulnerable because their homes are susceptible to flooding. Moving to higher ground becomes a necessity to avoid being trapped and new burrows need to be established quickly in order to be protected from predators, competitors and the weather.  It was during this time that several of our collared desert kit foxes seemed to have “disappeared.”

When a collared animal goes “off-air” (meaning they cannot be heard via radio telemetry) and seemingly disappears, it is unnerving. As biologists, we have a responsibility to the safety and well-being of a study animal and we do not want the collar to be the reason for any mishap that may occur in the animals daily activities. Additionally, these animals are part of a disease monitoring collaborative and they provide us with very valuable information. Not being able to find the carcasses means information is lost, which undermines the purpose of this effort. After several unsuccessful attempts to locate the animals on foot, it was decided that what we needed was an eye in the sky. We called upon the professionalism of warden-pilot Tom Evans. With his help, we were able to take to the sky and listen for our “missing” foxes. Thanks to Tom and all of his experience in aerial telemetry, we were able to locate and recover our missing foxes. Amazingly, we were also able to clearly see the large den complexes our missing foxes created – from the sky!

A 2-element antenna affixed to the underside of an airplane wing. Often in radio telemetry the transmitter’s signal (in this case a radio collar) often travels upward, not outward. In flat areas, such as the desert, tracking animals can become difficult because gaining enough height to receive the signal is not always permissible. That is why aerial telemetry is an invaluable aid for biologist. Photo courtesy of WIL biological volunteer, Teri Baker.

You can read about what prompted the initial disease surveillance project by following our DFG News Blog. More about recent work can be found by clicking here.

Fisher Translocation Project Completes Successful Trapping Effort

by Deana Clifford, wildlife veterinarian

Here’s a post and a photo slide show from our colleagues working on  the Fisher Translocation Project. In this post, Kevin Smith describes our successful efforts to capture, examine and monitor fishers.

The Fisher Translocation Project is led by the CA Dept of Fish and Game (CDFG), the US Fish and Wildlife Service (USFWS), North Carolina State University, and Sierra Pacific Industries. The goal is to translocate fishers into a portion of their historical range in the northern Sierra Nevada. If successful, this project will provide significant benefits to the conservation of fishers in the state.

Photo of DFG Biologist releasing fisher into wild.

CDFG lead for the translocation, Richard Callas and biologist,  Scott Hill release a fisher into the northern Sierras.

Over the past 3 years we have translocated 40 fishers from Northern California to the Stirling Management Area in the northern Sierra Nevada. Although it will take many years to determine if a permanent population will become established, early findings indicate that translocated fishers are successfully reproducing and that fishers born in Stirling are healthy.

The WIL nongame health program provides support to this project by conducting examinations, supervising immobilizations and training field crews. Along with our partners at the Integral Ecology Research Center, and the California Animal Health and Food Safety Lab, CDFG is monitoring the health of these fishers during and after release by determining the cause of any mortalities and conducting testing to determine what diseases fishers and other carnivores are exposed to.

See more information about this project.

HaPpY HaLlOwEeN!

All of us at the Wildlife Investigations Lab would like to wish you and your family a safe and happy Halloween!

Do you recognize this little bear cub enjoying a Halloween treat? It may be difficult considering she has a beautiful, thick coat of hair growing in! Click here to read about her  amazing recovery.

Beauty is in the Eye of the Beholder: A Story About a Little Bear that Could.

by Jaime Rudd, WIL Scientific Aid

In July, Fish and Game responded to a call from a homeowner in San Luis Obispo who reported something was in the backyard. When game wardens arrived, they found a young black bear cub with a very unusual problem – she had no hair.

Week 5. Posing candidly while patiently waiting for her morning meal.

After determining that the cub appeared orphaned, Fish and Game officials captured the cub and transported her to the Wildlife Investigations Lab (WIL) where she was examined by veterinarians Ben Gonzales and Deana Clifford. The cub was about six months old, 20 pounds underweight, dehydrated and she had a severe skin infection. Diagnostic tests were run including a complete blood panel, skin scraping, fungal culture and intestinal parasite exam. Her blood results were typical of a malnourished, dehydrated young animal with a compromised immune system. Her culture grew a fungus and microscopic examination of the fungus identified the culprit as Trichophyton mentagrophytesringworm, a highly contagious and zoonotic (meaning, it can be transmitted from animals to humans) disease. Skin scraping results also revealed the bear cub was heavily infested with Ursicoptes sp., a mange mite known to infect bears.

Mange, also known as scabies, is a skin disease caused by a microscopic mite that parasitizes the top layer of skin. Depending on the species of mite, mange can be highly contagious between mammals, and sometimes from mammals to people. As far as we know, Ursicoptes sp. is not zoonotic. As the mites burrow into the skin, they cause an allergic reaction which leads to crusting of the skin and intense itching. Severe infections cause hair loss (alopecia), thickening and scabbing of the skin. Secondary fungal and bacterial infections commonly occur, which cause deep and superficial pyoderma (skin infection), leading to further degradation of the skin, the body’s first defense against disease.

Mange has been reported in numerous wildlife species and it can also afflict domestic animals and humans. Animals that are severely infested typically show signs of poor health. While spontaneous recovery can occur, this disease can be fatal as the infection progresses. In the past few years, wildlife biologists have observed a rise in mange cases affecting local wildlife populations. Bighorn sheep, bobcats, mountain lions, foxes, coyotes, squirrels, and bears are a few of our valuable species that are vulnerable to mange mites.

Our veterinarians had a big decision to make. If we treated this little bear, she would not be a good candidate for rehabilitation and eventual release. It can take animals with infections this severe many months to regrow all their hair. Intensive treatment and care would be required over a long period of time, during which time she could become habituated human caretakers. Also, both mange and ringworm are contagious to other bears, so she could not be housed with other cubs for company. However, if we decided not to treat her and release her back into the wild, her chances of survival were extremely poor – especially with the coming winter.

After careful consideration, WIL veterinarians decided the best course of action was to treat the cub until we could transfer her to an approved zoo. Because this little cub had been sick for so long, her natural defenses to ward off disease and infection were shut down.

So, how would WIL go about treating such a heavily parasitized little bear? There is limited literature about how to successfully treat wild black bears with infections this severe. We knew we had to treat her parasite, fungus and bacterial infections all at the same time.

She was given an antibiotic for her bacterial skin infections that was specially made to be peanut butter-flavored. She was also given an injection for the mites but her systemic treatment for the ringworm infection was postponed for a week due to potential side effects that could result because of her poor overall health. She was bathed using a specially medicated shampoo to clean and soothe her skin and dipped in lime-sulfur – a treatment that would help kill both the parasitic mites and the ringworm. Subcutaneous fluids were given to boost her hydration.

Each week, the cub would need to receive a bath and a dip as well as an anti-parasitic injection (which should be given for up to 6 weeks). Twice a day she would receive an antibiotic for her bacterial skin infections and once she was healthy enough, she would require twice daily antifungal medication. Not to mention round-the-clock care and feedings until she could maintain a healthy body weight … and the WIL staffers all signed up!

Week 4. How do you go about giving a bear oral medication? Hide it in a grape of course! Luckily for us, this little bear loves grapes and happily eats them – even if they have pills hidden inside! Here, she is displaying her great balance after eating her evening meal and medication.

After 3 months of intensive care; this cub has tripled in size and is starting to develop a fine coat of new hair. Her blood chemistry has improved and for the past three weeks tests have detectged no mites. She has made giant leaps toward recovery and is doing well on systemic antifungal treatment.  Her fungal culture has not had any growth for more than a week.  She will continue to be treated until we are confident her infection has resolved and she has completed the medication regimen. It will be months, possibly more than a year, before she has a complete hair coat but to us she is a beautiful baby bear.

So what will become of the little bear? When we feel confident she is not contagious and is healthy enough for travel, she will be transported to her new home at the Gladys Porter Zoo in Brownsville, Texas, where the bear keepers are anxiously awaiting her arrival.

Week 8. Starting to look like a bear! A hairless bear poses many challenges. One such problem is her inability to thermoregulate normally. While Sacramento summer days are nice and warm, it can be cold at night. Here at WIL, our bear dens have specially heated floors. Pair that with a cozy crate and wool blankets, then you have a safe, warm haven for a hairless bear! In this photo, she awaits a cool treat-a homemade popsicle of water and fresh fruit pieces!

The decision to treat this little bear has contributed to our understanding of mange and ringworm in bear cubs.  At WIL, it is our hope that what we have learned will lead us and others to better understand the impact of mange and related diseases and contribute to more effective treatment of future cases.

Special thanks to the WIL staff and volunteers who have given this little bear extraordinary care. Also thank you to Dr. Larry Buntrock and the staff at San Juan Veterinary Hospital in Citrus Heights for donating medications to the lab, Douglas Feed and Pet Supply, and to Raley’s for donating produce – especially those grapes she loves so much!

WIL Photo of the Week – Desert Sunrise

A picture is worth a thousand words … wonder what this little desert kit fox has to say about the monsoonal summer in California’s Colorado Desert? More information about the desert kit fox project can be found by following the link.

This radio collared desert kit fox (Vulpes macrotis) is part of an ongoing disease monitoring effort in eastern Riverside County. Remote cameras are placed at kit fox dens and used to capture still images of its inhabitants. This is a useful, non-invasive tool biologists can use to monitor the health and physical condition of these crepuscular animals. Photo courtesy of David Elms from Region 6 DFG office.