Photo Album of Large Mammal Captures – Spring 2014

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.

Large mammal project locations.  Spring 2014

Large mammal project locations. Spring 2014

Bandaging elk antlers to prevent injury

Bandaging elk antlers to prevent injury

Stabilizing elk for transport to trailer for relocation to another site.

Stabilizing elk for transport to trailer for relocation to another site. San Luis Refuge, US Fish and Wildlife Service, Merced County.

Pronghorn antelope

Pronghorn antelope, Modoc County. Photo by Richard Shinn.

Helicopter bringing deer into basecamp for health monitoring

Helicopter bringing deer into base camp for health monitoring, Inyo County

Translocation and release of Sierra Nevada bighorn to augment herd in Olancha

Translocation and release of Sierra Nevada bighorn to augment herd in Olancha, Inyo County.

Deer release after GPS collaring and health monitoring - Scott Valley, Siskiyou County.

Deer release after GPS collaring and health monitoring – Scott Valley, Siskiyou County. Photo by Eric Haney

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The Tule Elk, A California Comeback Story

By Tom Batter, WIL Scientific Aid

The elk (Cervus canadensis) to this day remains an icon of what once was the unsettled, untamed American frontier.  There are four extant subspecies of elk in North America.  The Manitoban elk (C.c. manitobensis) is exclusive to Canada, but the other three subspecies can be found in California.  They are the Roosevelt elk (C.c. roosevelti) of the north coast rainforests, Rocky Mountain elk (C.c. nelsoni) of the northeastern counties, and the tule elk (C.c. nannodes) native to the Central Valley.

Elk distribution in California.

Elk distribution in California.  Photo courtesy of the DFW Elk Management Program.

Tule elk look similar to other elk in general size, shape, and color (albeit tules wear a slightly lighter brown).  Generally speaking, however, tule elk are overcome in maximum size by both Rocky Mountain elk and the great Roosevelt elk.  A good sized Roosevelt bull, the largest of the subspecies, can reach 1,000 pounds or more.  Tule elk are the smallest subspecies; in fact, at one time they were colloquially referred to as ‘dwarf elk’.  A large bull tule elk will tip the scales at about 700-800 pounds (hardly a ‘dwarf’ by any means), yet under ideal conditions they may grow larger.

The tule elk, the smallest of the elk subspecies, are best adapted to open country and semi-desert conditions among elk races (McCullough 1969).  Image source: CDFW

Tule elk once roamed the San Jaoquin Valley in ample numbers.  Early settlers found tule elk roaming the foothills of the Sierra Nevada west to the central Pacific coast and from the headstream of the Sacramento River south to the Tehachapi Mountains.  Much like the affliction of the American bison on the Great Plains, tule elk became a casualty of human settlement — particularly after the Gold Rush.

Unregulated market hunting, competition with livestock, and the introduction of nonnative plant species all contributed to the decline of tule elk.  What was more devastating, however, was the conversion of elk habitat to agricultural land.  When settlers turned to the plow not only did it remove food and cover resources for elk, it also brought about direct conflict between elk and farmers.  Increasing crop and fence damage fueled campaigns for the removal of the tule elk by those individuals whose livelihoods were affected.  By the time elk hunting was banned by the state legislature in 1873, it was unknown if any tule elk even remained.

Luckily tule elk did remain, thanks in part to the protection provided by California cattle baron Henry Miller.  In 1874 a pair of Tule elk was discovered on the Miller and Lux Ranch by a local game warden at Button Willow.  Miller set aside 600 acres (near present day Tule Elk State Natural Reserve) to give the elk a chance to rebound.  In 1914, the elk had experienced such growth in numbers that Miller requested the California Fish & Game Commission work to relocate the elk from his ranch.

In order to relieve Miller from elk damage to his property and crops (reportedly estimated at $5,000 per year), the U.S. Biological Survey attempted to relocate tule elk by lassoing them from horseback and transporting them to new areas, with little success.  From 1914 to 1934 the California Academy of Science took on tule elk relocation activities 21 times over the next several decades.  These attempts were not very successful either, although they did contribute to establishing the herds at Owens Valley, Cache Creek, and the Tupman Reserve.

From 1971 through 1989 complete species protection was granted to tule elk.  State and Federal laws were passed to prohibit hunting of tule elk until a population of at least 2,000 was reached.  Habitat improvement programs combined with an aggressive reintroduction campaign by the Department of Fish & Game and other state and federal agencies yielded a significant increase in California’s tule elk population.

Tule elk of the San Luis National Wildlife Refugre, circa 1970s.  Image source: BLM 3rd Annual Report to Congress on The Tule Elk.

Tule elk of the San Luis National Wildlife Refuge, cca the 1970s. Image source: BLM 3rd Annual Report to Congress on The Tule Elk, March 1, 1979.

Today there are twenty-two tule elk herds in the Golden State, totaling around 4,200 individuals with the population trending upward.

Due to competing land use practices, it is not easy for tule elk to freely move between sub-populations; this requires the Department of Fish & Wildlife to take action in order to meet statewide management objectives.To help maintain healthy herds, every so often CDFW is tasked with capturing and relocating healthy elk to different established

Dr. Annette Roug (right, kneeling) leads a team of biologists as they attempt to weigh a cow elk.  Photo credit: Joe and Nancy Rodrguez.

Dr. Annette Roug (front right) leads a team of biologists as they attempt to weigh a cow elk. Photo credit: Joe and Nancy Rodrguez.

herds.  Removing elk from one herd and placing them in another helps to simulate the natural movement of individuals between herds which increases genetic diversity, an important function of a healthy population.

The Wildlife Investigations Lab took part in one such capture and relocation effort at the end of March.  A total of 36 elk were captured via helicopter from the San Luis National Wildlife Refuge near Los Banos.  Once elk were netted from the helicopter, they were processed by capture teams.  Capture teams took measurements, collected hair, blood, and other biological data to assess the health of the herd before they moved on to their new locations.

The animals were successfully released to join their new herds.  A portion of the captured animals were also radio-collared to collect post-release movement information.

An elk sets eyes on joining its new herd.  Photo courtesy of Joe and Nancy Rodriguez.

An elk sets sights on joining its new herd. Photo courtesy of Joe and Nancy Rodriguez.

To read the CDFW news release from this successful capture, click here.

For more information on the CDFW Elk Program, click here.

Interested in more tule elk biology?  Click here.

 

 

Drought and the Impact on California’s Wildlife

By Tom Batter, WIL Scientific Aid

California has been experiencing persistent dry conditions since 2012.  According to the National Drought Mitigation Center at the University of Nebraska-Lincoln, 99% of California is currently abnormally dry, 67% of California is in extreme drought, and almost 10% is experiencing exceptional drought — and it may not let up soon.  The implication of a drought emergency is relatively straightforward: there is a severe lack of water.  This lack of water affects Californians in many ways, be it economically or socially.  But how does it affect the state’s wildlife?

Nearly 99% of California is abnormally dry, while 63% of the state is experiencing extreme drought (as of February 4, 2014).  Photo courtesy of the U.S. Drought Monitor.

Nearly 99% of California is “abnormally dry”, 67% of the state is experiencing “extreme drought”, and 10% is experiencing “exceptional drought” (as of February 4, 2014). Photo courtesy of the U.S. Drought Monitor.  Click here for the most up to date drought conditions in California.

California’s wildlife depends on water just as it’s citizens do.  With water resources becoming increasingly rare, a “domino effect” takes place in the ecosystem. Drought conditions negatively impact habitat through resource deterioration and wildfire, causing migration and behavior changes of animals.  Wildlife become concentrated in remaining suitable habitat, increasing chances for disease outbreaks due to close contact.

It begins at the producer level.  As drought intensity increases, vegetation growth is stymied.  Plants that lack necessary water resources respond by reducing new stem growth while previously produced stems will shrivel and die.  The obvious effect from lowered plant production is a reduction in food availability for herbivores.  This in turn reduces populations of insects, reptiles, wild rodents, and hares which many small carnivores and raptors rely upon for food.

Dry conditions in cache creek, Yolo County.  Photo credit: Krysta Rogers, WIL.

Dry conditions at Cache Creek, Lake County, in late December 2013. Photo credit: Krysta Rogers, Wildlife Investigations Lab (WIL).

With lower food availability, animals tap into their body’s fat reserves. Utilizing fat reserves will ultimately lead to starvation for wildlife whose nutritional needs are not eventually fulfilled. Beginning in mid-December, WIL began documenting increased mortality of young red-tailed hawks in central and southern California. Investigation revealed poor body condition, emaciation, and secondary bacterial or fungal infections. A similar event occurred the previous winter, also in dry conditions.

Red tailed hawk.  Photo courtesy of the U.S. Fish & Wildlife Service

Drought impacts all trophic levels, including birds of prey such as the red-tailed hawk (pictured). Photo credit: U.S. Fish & Wildlife Service (USFWS).

Reduced plant growth also negatively affects available cover for wildlife.  Cover is an important element for prey species to evade predators.  As plant life diminishes, landscapes become more open.  For some wildlife, such as ground nesting birds, the likelihood of predation increases as these drought ridden landscapes open up.

With the odds already stacked against them, wildlife in drought conditions are also forced to travel greater distances in search of food and water resources.  Some behavior changes may take place as a result; for example, typically nocturnal species such as raccoons and opossums may remain active well into the daylight hours seeking food.  The extra effort for nutrients puts these animals at an increased risk of exhaustion, starvation, predation, and disease.

As drought conditions persist, animals will seek out alternative habitats that have more favorable conditions for survival.  Areas where food and water are still available will attract many species to a relatively small area.  Predation rates are likely to increase as predators can more easily focus on a centralized group of prey.  Furthermore, large concentrations of wild animals increase the odds for disease outbreaks that could decrease populations.

In fact, this winter WIL has already investigated several avian cholera outbreaks throughout California. Large numbers of ducks, geese, and swans spend the winter on the state’s many ponds and lakes. The current lack of precipitation has reduced the amount of habitat available for these birds, forcing them to become concentrated in locations where water remains. Close contact among waterfowl allows a bacterial disease like avian cholera to spread very rapidly, resulting in the death of hundreds to thousands of birds.

Large concentrations of waterfowl seek out remaining suitable habitat. Photo credit: Scott Flaherty, USFWS Pacific Southwest Region.

A variety of waterfowl species congregate at the Sacramento National Wildlife Refuge.  Photo credit: Scott Flaherty, USFWS Pacific Southwest Region.

While these impacts of drought do indeed create dire circumstances for wildlife, it is important to remember that droughts are natural phenomena.  Wildlife and drought have coexisted for generations upon generations.  Generally speaking, wildlife populations are resilient and are able to bounce back from drought events once typical weather patterns return.  For example, in the early 1960s severe winter drought contributed to extreme deer die-offs in Texas.  When rainfall levels returned to normal, the deer population was able to rebound in only one year.

Many species of wildlife, such as mule deer, are capable of bouncing back after drought once favorable conditions return. Photo credit: T.A. Blake, USFWS

Many species of wildlife, such as mule deer, are capable of bouncing back after drought once conditions return to normal. Photo credit: T.A. Blake, USFWS

During these hard times, it may be tempting to “rescue” or “save” an animal that is seeking food and water.  It is entirely possible that more wildlife will make their way into urban and residential areas in an attempt to find nutrients.  It would be a disservice to both human and animal to offer handouts, for similar reasons it is inappropriate to keep wildlife as pets. This natural drought event will eventually pass, and when it does, CDFW and WIL staff would rather see California’s fauna remain reliant upon themselves rather than their human counterparts.

Got Acorns?

If you have acorns in your area, be on the look out for band-tailed pigeons this winter. Band-tailed pigeons are California’s only native pigeon and this time of year, they will fly great distances to find acorns. Band-tailed pigeons are one of the rare bird species that will actually swallow acorns whole! Unfortunately, this behavior also makes them more susceptible to Trichomonosis, a disease caused by a single-celled microscopic protozoan parasite, Trichomonas gallinae.

Band-tailed pigeon. Photo by Krysta Rogers.

Adult band-tailed pigeon showing the characteristic white crescent and iridescent greenish-bronze patch of feathers on the hind neck and black band on the tail, for which the species was named. Photo by Krysta Rogers, 2013.

The parasite lives in the mouth and throat of infected birds, causing caseous (“cheese-like”) lesions to develop in the bird’s mouth or esophagus. As the lesions become larger, the pigeons can no longer swallow acorns, leading to weight loss and eventually death. The lesions also may cause the pigeon to suffocate, if they block the airway.

Band-tailed pigeons with Trichomonosis. Photos by Jeff Cann & Krysta Rogers.

Fig. 1: A band-tailed pigeon showing signs of infection with Trichomonosis.
Fig. 2: A dead band-tailed pigeon observed during a Trichomonosis die-off in 2012.
Fig. 3: Caseous lesions in the oral cavity of a band-tailed pigeon with Trichomonosis.
Photos by Jeff Cann (Fig. 1) & Krysta Rogers (Fig. 2 & 3).

While this disease can make pigeons sick any time of the year, large-scale die-offs only occur during the winter, in some years. The last series of mortality events were reported in 2012 in California, when up to 10,000 pigeons were estimated to have died between December and March. Recent research by CDFW suggests that these mortality events are more likely to occur in winters with low precipitation, similar to the conditions we’ve been experiencing so far this winter.

So, if you have acorns, be on the lookout for band-tailed pigeons and enjoy watching them comically hang from the branches as they try to reach an acorn. Hopefully, the pigeons will not experience any die-offs this winter. However, if you do happen to see pigeons that appear sick, such as showing signs of weakness, labored breathing, breathing with their bill open, drooling, reluctance to fly when approached, or are dead, you can help by reporting the mortality to the Wildlife Investigations Lab.

If you have any questions, or would like to report sick or dead band-tailed pigeons, contact Krysta Rogers at 916-358-1662.

Disease Surveillance Projects for Bighorn Sheep Completed in November

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Dr. Colleen Duncan from Colorado State University and Dr. Ben Gonzales from California Department of Fish and Wildlife collect biological samples from bighorn sheep for disease testing. (Photo courtesy of George Kerr, Society for the Conservation of Bighorn Sheep)

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.

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Taking blood samples from bighorn sheep for use in disease testing. (Photo courtesy of George Kerr, Society for the Conservation of Bighorn Sheep)

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Inspecting bighorn for signs of respiratory distress. (Photo courtesy of George Kerr, Society for the Conservation of Bighorn Sheep)

Why is it important to report wildlife mortalities?

Over the past 12 months, the Wildlife Investigations Laboratory has been asking the public for their assistance in reporting wildlife mortality events.  WIL recognizes that mortality reports are an important tool in monitoring the health of the State’s wildlife. Wildlife mortality reports can:

  • help us better understand these phenomena;
  • lead to more effective prevention and control;
  • potentially detect emerging diseases affecting fish and wildlife; and
  • recognize problems that could affect human and domestic animal health.

WIL received 30 mortality reports submitted by the public from July 2012 – June 2013.  These reports documented mortalities in 21 different species and have been added to a permanent record so that we may potentially be able to detect phenomena such as seasonal mortality trends or weather mortality events in the future.

Mortality Reports:  July 2012 – June 2013

CDFW - WIL Wildlife Mortality Reports, 2012-2013

CDFW – WIL Wildlife Mortality Reports, 2012-2013

Public reporting makes a valuable contribution to the information we are trying to collect and is an important source for disease outbreak monitoring and emerging health threats. Please help us monitor the fish and wildlife populations in California.

For more information on wildlife mortality reporting, please follow the links below.

California wildlife mortality reports:

http://dfg.ca.gov/LivingWithWildlife/Mortality/

California roadkill tracking:

http://www.wildlifecrossing.net/california/

Wildlife heath information:

http://www.nwhc.usgs.gov/map/mortality_events.jsp

http://healthmap.org

www.wher.org

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.