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.

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.