Science Spotlight

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  • July 13, 2018

A man on a horse with a mule in tow, climbing rugged, mountainous, dry scrub-covered terrain
a man's hand laid flaat on sandy soil, next to a mountain lion track
A golden-coated mountain lion sits high on a large limb of an oak tree
Man wearing a hard hat and climbing gear, working his way up a tall pine tree, under a royal blue sky
A mountain lion crouches, well camouflaged by boulders and sandy soil under dead branches

It’s just before dawn in the eastern Sierra Nevada Mountains in Mono County. It’s a cold clear morning, a good day to be out experiencing a still very much wild area of California. California Department of Fish and Wildlife (CDFW) biologist Justin Dellinger and a Wildlife Services houndsman are preparing gear to go out looking for fresh mountain lion tracks in this vast landscape. With the help of a team of highly trained dogs, Dellinger and the tracker are focused on the ultimate goal: Capturing a mountain lion and outfitting it with a GPS collar for research purposes.

This tracking effort in Mono County is part of a larger project to estimate mountain lion population size statewide. It began in the southern Cascades and northern Sierra-Nevada Mountains in 2015, and since then CDFW has solely undertaken or collaborated on similar efforts in the north coast, Modoc plateau and here in the eastern Sierra Nevada Mountains. It’s tough work with long hours; trackers can spend days or even weeks in pursuit of lions. Yet tracking remains the gold standard method of gathering data in the mountain lion research world.

Notably, it takes both biologist and houndsman, each with a unique skill set, to make this team effort work. On this particular day, for example, Dellinger starts the ball rolling when he spots a fresh set of mountain lion tracks made the night before. The mark of the hind heelpad, measuring 52mm across, indicates that it’s a tom (male cat) heading southwest. The long stride suggests he’s traveling in a focused and determined manner – perhaps to secure a meal, locate a mate or confront another male trying to move in on his turf.

Dellinger radios the houndsman, who is astride a mule. The houndsman makes his way to the tracks with dogs in tow, where he assesses a wide variety of information – the time of day, wind speed and direction, topography, etc.

“The mental calculations (of the tracker) are rooted in decades of experience and know-how, but they’re still somewhat of an enigma to me,” Dellinger says. “But then again, houndsman feel likewise about the statistical calculations employed by biologists. It takes both of us, working together, to compile all the information and derive a solid population estimate.”

Over the next several days, the houndsman and the biologist follow the tom over miles of country, with the cat none the wiser about his pursuers. The team eventually catches up to the tom. The dogs masterfully trail him over boulders and around escarpments and tree him in a pinyon pine. The houndsman signals to Dellinger that the tom is treed. Dellinger then works his way into position to dart the animal. Success! Within an hour, the cat is asleep and Dellinger is able to affix a collar.

Yet despite the enormity of the overall effort, the day’s accomplishment is only one small step in the overall plan. Simply put, they’ll get a little rest and then wake up and try to do it all over again tomorrow.

As CDFW’s lead mountain lion biologist, Dellinger understands the need to study and understand Puma concolor only too well. “Lions are the apex predators across much of California, and apex predators can tell scientists a lot about the ecological wellbeing of a given landscape or ecosystem,” he explains. “If mountain lions are decreasing in an area, it’s likely that prey species are decreasing too. If mountain lions are exhibiting health issues, it’s likely that other animals in the ecosystem are experiencing similar issues.”

Because of those grants, this first comprehensive effort to collar lions around the state is now underway. It’s a huge and somewhat daunting task. California’s size and ecological diversity requires a divide-and-conquer approach, meaning that studies can only be conducted in one area at a time. Together, those “slices” of data will add up to a statewide picture. 

Getting the collar on the cat might be the most important part, but all of the data Dellinger collects on this trip will be useful. He’ll be able to compare tracks and remote game camera photos with GPS collar data to derive a minimum count of mountain lions in the area. For now, this is the best way of counting mountain lions in the western United States. In the future, CDFW may grow to rely on data gathering techniques that are more cost- and time-effective than tracking, and use more common skill sets. One possible alternative is developing thanks to the rapid advance of using genetics to monitor wildlife species without having to handle the animals. Scat samples can be collected and analyzed to provide a genetic fingerprint of the animal that deposited them. In theory, if enough lion scat is collected over a large enough area, CDFW can estimate the number of lions in the area.

But scat analysis is still a fairly new way of doing things, and until techniques can be tested, compared and perfected, CDFW will continue to employ the tracking “gold-standard.” The newer methods can be compared to the old, and it’s possible that the newer methods will outperform (i.e., be cheaper and just as reliable) the older methods in some areas but not other areas.

CDFW sees this statewide effort as a first step in monitoring and conserving the elusive, ecologically important mountain lion long-term in California. The project is still in its early stages and will likely continue for another six years or so. Dellinger is enthusiastically looking forward to the work. “It’s really cool because no other state has attempted such a comprehensive population assessment of lions … and  no other western state is as ecologically diverse as California,” he says. “Doing something this comprehensive requires working in a lot of very unique areas. It’s never going to be boring.”

Photos courtesy of Justin Dellinger

Categories: General
  • January 22, 2018

silvery tilapia skin on the bottom of a bear's paw
The tilapia skin is visible on the bottom of the bear's paw.

Two veterinarians look at an ultrasound image, behind an anesthetized bear lying on her back.
Veterinarians perform an ultrasound to check on the progress of the second bear's pregnancy.

An anesthetized adult bear lies on her side, on a veterinary table, with eight acupuncture needles stuck in her legs, shoulder, paws and snout
Acupuncture needles assist with pain management.

A sad-looking bear looks up from an artificial enclosure
After placing the second bear, the team moved the first bear to another location where another man-made den awaited.

Two women and a man build a bear den of fallen logs and forest materials in the wilderness
CDFW staff work together to build a makeshift den for a soft release in Los Padres National Forest. A soft release involves putting the bear in a den to simulate hibernation, and leaving it to wake up on its own.

Two talented veterinarians, an environmental scientist and several dedicated staff members at the CDFW Wildlife Investigations Lab recently put their heads and their resources together to help heal a pair of adult bears that were badly burned in the Thomas Fire. The bears, which were treated at the same time as a young mountain lion with similar, less severe burn injuries, were released back to the wild last Thursday, after several weeks of intensive – and unusual – care.

CDFW Senior Wildlife Veterinarian Dr. Deana Clifford was acting manager of the Wildlife Investigations Lab in Rancho Cordova when the first bear – an adult female weighing about 200 pounds – was captured inside of a backyard aviary in the Ojai area on December 9. With CDFW Environmental Scientist Christine Thompson coordinating, CDFW Wildlife Officer Jacob Coombs darted the bear and local veterinarian Dr. Duane Tom evaluated its injured paws and overall condition. Thompson then conferred with Clifford, who determined the bear might have a chance at recovery if treated quickly. The bear was put into a trailer for the seven-hour transport to Rancho Cordova, where Clifford was waiting.

By the time the bear arrived, Clifford had already reached out to Dr. Jamie Peyton, Chief of Integrative Medicine at the UC Davis Veterinary Teaching Hospital, for help. Weeks earlier, Peyton, who works mostly on domestic animals, had mentioned to Clifford in passing that she had a particular interest in animal burns, and would be interested in helping wildlife if the chance ever arose.

Peyton created a homemade burn salve for the bears’ paws, and a process for sterilizing tilapia skin. Fish skin, which contains collagen, is often used by doctors in Brazil to bandage human burns. The technique is not yet approved by the Food and Drug Administration for use in the United States, and had not been tried on veterinary patients.

To help keep the tilapia skin in place, Peyton cut pieces to exactly match the size of the bear’s paws and then sutured them over the wounds while the bear was under anesthesia. Additional temporary wrappings, including rice paper and corn husks, were added, with the intention of stretching out the amount of time it would take for the animal to chew down to the fish skin bandage. “We expected the outer wrapping to eventually come off, but we hoped the tilapia would keep steady pressure on the wounds and serve as an artificial skin long enough to speed healing of the wounds underneath,” Peyton said. She also used acupuncture to aid the bear with pain management.

The original plan was for Peyton to come to the lab weekly to check on the bear’s progress. But within just a few weeks, two more burn patients arrived from the Thomas Fire. A second adult female bear, found relatively close to where the first one was found, was brought to the lab by Thompson on December 22. And on December 23, the young mountain lion arrived from Santa Paula. The experimental tilapia treatment was extended to the two newcomers as well.

Of the three animals, the mountain lion’s injuries were the least severe. Because of his young age, he was earmarked for placement in a wildlife rescue facility. The two bears were in much worse condition, with oozing wounds and, in some cases, paw pads that were completely burned off. But because the bears were older and stronger, the veterinarians hoped to return them to the wild if their injuries could be healed.

To complicate matters further, on December 28, during a routine burn treatment, Clifford’s team performed an ultrasound on each bear, and found that the second bear was pregnant. The quest to heal the mother-to-be was now a race against time.

“That was a game changer for us, because we knew it wouldn’t be ideal for her to give birth in confinement,” Clifford said. “We aren’t really set up to have a birth at the lab holding facilities, and we knew there was a high probability that she could reject the cub, due to all the stress she was under. We needed to get her back into the wild as quickly as possible.”

While Clifford and Peyton continued to focus on healing the animals’ injuries, Thompson started scouting out potential release locations. Since both bears needed to be transported back to Southern California, it was decided to try to return them at the same time – albeit not exactly in the same location – in order to make the best use of staff time and resources.

Both bears’ original habitat had been destroyed by fire, so Thompson scouted for two new locations that fit several parameters. The bears needed to be close to their home range, but not within the burn area, and near ample food and water sources. She also wanted to keep them as far away from each other as possible. “A lot of wildlife habitat was destroyed by the fire, and there are already a lot of displaced animals roaming around,” Thompson said. “So there’s a good chance that whatever location we choose is already occupied by other bears, but only they know exactly where that designated territory is. The best we can do is make an educated guess, and place them as deep into wild lands as possible.”

Taking the rapidly changing winter weather reports into careful consideration, the team chose Wednesday, January 17, as the target date to get on the road. That morning, Peyton came to the Wildlife Investigations Lab one last time and both bears were immobilized for a final treatment for their feet. Then the bears were placed into separate transport trailers for the long journey home. Simultaneously, in the Los Padres National Forest, Thompson and Tom spent the day digging dirt and moving logs to create a winter den for each bear.

“At this time of the year, most bears have established dens for the winter, but since these bears won’t have time to create a den, we hope to improve their chances of survival by creating a den for them so they have a home base and shelter right away,” Clifford explained.

The team arrived late Wednesday night, and both staff and bears were hosted overnight by the Ventura County Sheriff’s Department. Early on the morning of January 18, Clifford, Thompson, Coombs, Tom and their team drove the bears deep into the forest for the final leg of their journey. One at a time, each bear was sedated and carefully placed into her den, while the team finished constructing a shelter around the slumbering animal. The bears are about five miles apart, as the crow flies, and each is wearing a satellite collar so CDFW can monitor her movements and survival post-release. Staff also placed trail cameras near each den.

“We’re really hopeful that these novel treatments accelerated the healing for these bears and provided them the best odds of survival,” Clifford said. “It’s especially good to know that we’ve maximized the odds of survival for the cub on the way. We don’t know exactly when it will be born, but hopefully we’ll be able to monitor the movements of the mother via satellite, and that will give us an indication of how things are going.”

For Clifford, the entire experience wasn’t simply about saving the lives of two bears. The bigger picture involves the body of knowledge the experimental treatment provided – both to the Wildlife Investigations Lab team and to the UC Davis Veterinary Teaching Hospital.

“This treatment has the potential to be used successfully on all kind of burn patients, both domestic and wild,” Clifford said. “For us, at the Wildlife Investigations Lab, it’s been an invaluable experience because California’s changing climate means that we’re likely to see more wild animals impacted by catastrophic wildfires. By better understanding what resources are needed to care for injured wildlife and what treatment techniques increase healing speed, we can make the most informed treatment decisions, reduce animals’ time in captivity and provide guidance to other facilities caring for burned animals.”

CDFW photos. For more, please see CDFW’s Flickr photo album: link opens in new windowThomas Fire Bears.

Top photo: The first bear rests in her holding enclosure after her treatment is finished. The outer wrapping on her feet (made of corn husks) will delay her efforts to chew off the tilapia skin bandages underneath.

Categories: General
  • August 15, 2017

The latest issue of California Fish and Game, CDFW’s scientific journal, is now available online. This century-old quarterly journal contains peer-reviewed scientific literature that explores and advances the conservation and understanding of California’s flora and fauna.

The endangered salt marsh harvest mouse (Reithrodontomys raviventris) graces the cover of California Fish and Game, Volume 103, Issue I. Researchers ventured into the pickleweed to study the tiny mouse, which is endemic to the marshes surrounding the San Francisco Estuary Bay and its tributaries. The mice were fitted with tiny radiotelemetry collars and tracked for three years. Researchers documented some curious behavior in the resulting paper, “Potential evidence of communal nesting, mate guarding, or biparental care.” The accompanying photos provide a fascinating glimpse into an active nest.

Another paper, “Documentation of mountain lion occurrence and reproduction in the Sacramento Valley of California,” explores the potential for mountain lions to exist in fragmented habitats if there is adequate connectivity with larger blocks of suitable habitat and sufficient prey. The study used camera traps to document populations of mountain lions in the Sacramento Valley’s Butte Sink, which is made up of relic riparian habitats interspersed with managed wetlands. The photos show healthy mountain lions moving through habitat that has long been considered unsuitable due to extensive agricultural and urban development.

The article, “Mussels of the Upper Klamath River, Oregon and California,” reports on sampling efforts that expand existing baseline population data on freshwater mussels in the Upper Klamath River. The sampling efforts may ultimately assist with protection, mitigation and enhancement efforts for large bi-valve species.

The final paper provides insights into the benefits deer and elk derive from licking mineral rocks. Researchers took samples of “lick sites” that were used by California black-tail deer (Odocoileus hemionus columbianus) and Roosevelt elk (Cervus canadensis roosevelti) in the Klamath Mountains, Siskiyou County. After performing a detailed analysis of the elemental content of each lick site, the researchers concluded that each lick site offers a different smorgasbord of minerals, and in varying concentrations. The study’s objective is to begin identifying, classifying, and analyzing important mineral lick sites to benefit future ungulate management efforts.

As it has for the past 103 years, California Fish and Game continues to publish high-quality, peer-reviewed science that contributes to the understanding and conservation of California’s wildlife. We look forward to witnessing the contributions of the next installment.

Download the link opens in new windowentire Winter Issue 103 (PDF) in high resolution, or browse individual articles in low resolution.

Categories: California Fish and Game Journal, Wildlife Research