Science Spotlight

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  • January 5, 2021

The link opens in new windowCalifornia Fish and Wildlife Journal concludes the 2020 Special Issue installments with the winter quarter’s Special Wildland Fire Issue. With this year’s unprecedented fire season, and California’s fire-adapted natural communities taking center stage in land management discussions throughout the State and beyond, this issue is especially poignant as we reflect on this past year and contemplate the incoming new year.

Unlike previous Special Issues, this issue is divided into three sections: Vegetation Treatment and Policy, Fire Impacts on Plants, and Fire Impacts on Wildlife and Water. Each section highlights a piece of the wildfire and landscape management ‘puzzle’ through an examination of fire and its impacts on California’s fire-adapted ecological landscape.

One of these unique communities, the Pine Hill Ecological Reserve in El Dorado County, is home to almost 750 plant species, some of which can only be found at Pine Hill due to its unique soil composition. Researchers from CDFW, the California Native Plant Society and Sacramento City College investigate the impacts of different fuel-reduction methods on Pine Hill Ceanothus in link opens in new window“Effects of a firebreak on plants and wildlife at Pine Hill, a biodiversity hotspot, El Dorado County, California” (PDF). The article examines the effects of hand clearing and pile burning on chaparral species within the Wildland Urban Interface and the secondary impacts on wildlife. The study also includes the exciting discovery of new seedlings of Pine Hill Flannelbush, the rarest and most endangered plant in El Dorado county, and a fire-obligate germinator!

Plants that depend on fire to propagate aren’t the only plant communities impacted by the long-term fire suppression practiced in the western United States. New and updated technology is helping landscape managers and scientists study and assess the pre- and post-fire impacts to landscapes using remote sensing and modeling techniques. This type of data collection and analysis helps inform scientists and policy makers on landscape and watershed-level scales and helps focus efforts to manage habitats and sensitive plant communities before and after wildfires. One such effort is presented by Sonoma County scientists in link opens in new window“Sonoma County Complex Fires of 2017: Remote sensing data and modeling to support ecosystem and community resiliency” (PDF). With the help of NASA and other experts the team evaluates the impacts of the 2017 fires to woody vegetation within areas that burned during wind-driven and non-wind driven events to evaluate canopy condition. Using lidar data, the team identifies important predictors for post-fire woody canopy condition, which highlights the importance of high-resolution airborne mapping technology for informing management decisions.

Management decisions include when and how to monitor pre- and post-fire events, and the CSU Monterey Bay’s study link opens in new window“Analysis of the impacts of the Soberanes Wildlife on stream ecosystems” (PDF) highlights the need for monitoring wildfire’s impacts on coastal streams and benthic macroinvertebrate responses to fire events. This monitoring is especially important because macroinvertebrates are the foundation for in-stream salmon and steelhead foodwebs, and the ability of these microscopic organisms to recover from wildfire also impacts the recovery of these keystone species in California’s rivers and streams.

This quarter’s Special Wildlife Fire Issue also includes examinations of impacts and responses of Roosevelt Elk forage in Humboldt County, an essay on the California Vegetation Treatment Program, amphibian responses to wildfire and other topics that span California’s rich ecological diversity.

The California Fish and Wildlife scientific journal has published high-quality, peer-reviewed science that contributes to the understanding and conservation of California’s wildlife for more than 100 years. We look forward to the continued contributions in the next decade to come.

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Media Contact:
Kirsten Macintyre, CDFW Communications, (916) 804-1714

Categories: California Fish and Game Journal, Science Spotlight
  • March 7, 2019

Man wearing beige fishing hat, khaki pants, white long sleeved shirt, and backpack on rocky slope holding round red item
David Wright uses a mirror to reflect light into dark rock crevices in search of pika sign such as scat or urine stains. CDFW image by Joseph Stewart.

Large sheer rock mountainside with snow at peak and some trees. Man standing on rock appearing very small compared to the mountain.
Joseph Stewart hikes through one of the mountainous locations in the northern Sierra Nevada that researchers searched for habitat that appeared suitable for pikas. CDFW image by Johanne Boulat.

CDFW staff recently conducted a study to determine whether American pika in California are able to find sufficient refuge from elevated temperatures in their natural habitat. Previous CDFW collaborative research and related work has suggested that pikas in California and Nevada have been declining in warmer areas, but some scientists contend that underground temperature refuges will protect pikas from warming temperature trends.

“The question of whether pikas are protected or exposed to warming temperatures seemed key to us,” said David Wright, a retired CDFW senior environmental scientist who co-authored the research with Joseph Stewart, a former CDFW scientific aid and now a University of California, Davis post-doctoral researcher. “It is central to whether or not climate change is going to push pikas to higher, cooler elevations and significantly reduce and fragment their range, in our state, on our watch.”

Pikas are small herbivores related to rabbits that live in fields of broken rock (talus) in the mountains of western North America. Researchers examined 46 mountainous locations in the northern Sierra Nevada with habitat that appeared suitable for pikas.  

Pikas prefer talus with rocks eight inches to three feet in size, and larger or less isolated talus fields are generally more likely to support pikas.

“We did our research at elevations both within and below the expected elevation range of pikas,” Wright said. “Lower elevations on average have warmer temperatures, which pikas don't tolerate well, but it's been suggested that talus provides a refuge from warmer temperatures. We wanted to look at this hypothesis.”

Two species of pika occur in North America, with only the American pika found within the continental U.S. With their high metabolic rates and thick fur (including inside their ears and on the bottoms of their feet), American pikas are well adapted to cold temperatures at high elevations. They do not hibernate during the winter, and spend the summer gathering grasses and wildflowers to store in “haypiles” for subsistence during the winter. Hikers may know them from their distinctive alarm call, a high-pitched cross between a chirp and a bark.

In 2010 to 2013, using small, year-round temperature recorders lowered approximately 1.6 feet to 3.3 feet into talus, along with visual surveys for pikas or signs of pikas, Wright and Stewart found that temperatures below the talus surface were buffered from warm and cold extremes of ambient air temperature. This was consistent with previous findings.

However, pikas were not found wherever talus temperatures were suitable. Temperatures within talus were mostly suitable for pikas across all the study sites regardless of elevation, yet pikas were absent from many of the sites. Instead, summer air temperatures proved to be the best predictor of pika presence or absence. The warmest sites had no evidence of pikas, followed by warm sites that had only remnant fecal pellets (pika pellets can persist among the rocks for decades), then slightly cooler sites that supported pikas in some years but not in others, to the coolest sites which supported persistent populations of pikas throughout the study.

“It’s not enough to have suitable temperatures in their underground burrows,” said Stewart. “Pikas also need suitable temperatures above ground where they forage for food.”

The authors concluded, based on their own and other research, that daily warm air temperatures may inhibit pika foraging and survival because they cannot tolerate the heat, and juvenile survival and dispersal may be similarly impaired by elevated summer high temperatures. Talus provides a cool refuge for pikas up to a point, but beyond that point pikas still need to forage and complete the portions of their life cycle that occur aboveground. This balance point, from this research, appears to be near an average warm season (June to September) air temperature of 71 to 73 degrees.

Funding for this research and similar CDFW efforts in the Sierra Nevada are supported by State Wildlife Grants administered through the U.S. Fish and Wildlife Service.

link opens in new windowThe study, Within-talus temperatures are not limiting for pikas in the northern Sierra Nevada, California, USA, can be viewed here (PDF).

CDFW Photos. Top Photo: Pikas are small herbivores that live in fields of broken rock (talus) in the mountains of western North America. CDFW image by Jan Dawson.

Media Contact:
Kyle Orr, CDFW Communications, (916) 322-8958

Categories: Wildlife Research
  • December 14, 2018

Brown haired woman wearing glasses, white laboratory coat and white gloves in front of machine in laboratory
Kelly McCulloh loads evidence samples onto a DNA extraction robot.

Brown haired woman in white laboratory coat and white gloves holding pipette standing at counter in laboratory
Jillian Adkins prepares samples for DNA extraction.

Brown haired woman in white laboratory coat and white gloves sitting at desk with microscope and small tool in hand.
Erin Meredith uses a dissecting microscope to isolate hair roots for nuclear DNA extraction.

Long haired woman in white laboratory coat and blue gloves standing at laboratory machine with glass window partially lowered.
Ashley Spicer prepares a Polymerase chain reaction used in DNA sequencing.

If they weren’t so busy or their work wasn’t so mission-critical, you might find CDFW’s Wildlife Forensics Laboratory team on loan to the California Department of Education.

The four-person scientific team is all women with undergraduate and advanced degrees in biochemistry, genetics, molecular biology and forensic science.

Jillian Adkins, Kelly McCulloh, Erin Meredith and Ashley Spicer would be stars of state education initiatives to attract more girls to STEM (Science, Technology, Engineering and Mathematics) fields. They would be celebrated at school tours, asked to provide their personal stories at education conferences and inspirational messages in science classrooms across the state.

Instead, this team works mostly out of the spotlight, their scientific analysis critical to CDFW’s law enforcement mission to protect California’s natural resources and provide public safety. Increasingly, CDFW’s Wildlife Forensics Laboratory is being counted on to protect some of the most sensitive animal species on the planet.

“We just don’t lose these cases supported by forensic evidence. It’s amazing,” said Tony Warrington, a recently retired assistant chief who has managed CDFW’s crime lab for more than a decade. “Our forensic specialists do a fantastic job utilizing advanced scientific methods to support wildlife officers with poaching investigations and public safety wildlife incidents.”

Meredith, a senior wildlife forensic specialist with nearly 20 years at the lab, said the mere suggestion by a wildlife officer of sending evidence in for DNA analysis will sometimes prompt poachers to confess to their crimes. The lab is one of only about 10 wildlife forensic labs in the nation, giving CDFW wildlife officers a major crime-fighting assist. Every CDFW wildlife officer can access the lab, which processes evidence in about 100 criminal cases every year.

The white lab coats, antiseptic setting, high-tech equipment and talk of DNA sequencing invite comparisons to “CSI” – Crime Scene Investigations – the long-running night-time television drama that firmly implanted forensics in the public consciousness.

“My joke is always that human forensics is boring – you only work on one species,” Meredith said. “With wildlife, the possibilities are essentially endless.”

First established in the 1970s, CDFW’s Wildlife Forensics Laboratory has taken on a more prominent role with advances in genetic research and technology and the widespread acceptance of forensic evidence in the court system.

“If there’s blood on a knife, not only can we tell whether it’s from a deer, we can also tell whether it’s from a doe or a buck,” Meredith said. “We can tell if the blood on the knife originated from the same deer or evidence taken from a kill site or meat in a suspect’s freezer.”

Said Adkins, “DNA evidence has been a game-changer in determining guilt or innocence – in both people and wildlife.” Adkins’ work in providing quick turnaround of DNA samples allows wildlife officers to use the results to make critical enforcement decisions.

CDFW’s Wildlife Forensics Lab plays a key role in public safety and animal attacks that may involve great white sharks, coyotes, bears or mountain lions. With even minimal DNA evidence, offending species and animals can be identified with certainty in most instances.

“We literally free the innocent – and it’s happened a number of times,” Meredith said. “Our wildlife officers may trap what they think is the guilty bear, draw its blood and bring it to the lab for comparison with saliva from a bite wound or even a scratch mark on the victim. And if that DNA is not a match, that bear gets released.”

Retired assistant chief Warrington said, “This lab completely changed the way we deal with public safety wildlife. DNA matching has allowed CDFW to protect the innocent and positively identify the offending animal in these cases – a big step forward in protecting California’s wildlife.”

The lab marked another milestone in 2015 with the adoption of Assembly Bill 96, which closed a loophole in the state’s ban on ivory and made it illegal to purchase, sell, possess with intent to sell or import with intent to sell ivory or rhinoceros horn – with limited exceptions.

The legislation tasked a state wildlife agency with helping to combat the global ivory trade in order to protect ivory bearing species from poaching, exploitation and extinction worldwide. AB 96 provided funding for CDFW’s Wildlife Forensics Lab to add a fourth scientist in McCulloh.

McCulloh arrived with a master’s degree in forensic science from UC Davis. She has pioneered California’s genetics test for ivory products. It’s so accurate, it can distinguish African elephant ivory from Asian elephant ivory and even ivory from a long-extinct woolly mammoth.

Spicer, a native of British Columbia with degrees in biochemistry and forensic science, specializes in the physical characteristics of ivory that distinguish it among the many different ivory-bearing species – from elephant and hippopotamus to sperm whale and warthog – and also from non-ivory products such as synthetic ivory or plastics made to look like ivory. 
Spicer personally has worked on 17 of the 18 criminal ivory cases that have come through the lab since AB 96 was enacted. Her work has included serving as an expert witness and testifying at trial.

The lab’s contributions were link opens in new tab or windowheralded recently in the conviction of a Los Angeles County business owner on charges of selling two ivory tusks from Arctic narwhal whales. The tusks measured 79 and 89 inches long.

CDFW’s forensic scientists don’t necessarily mind all the newfound recognition – as long as the focus remains on their work.

Said Spicer, “We are really committed to the highest standards and ideals of science.”

YouTube Video Link: link opens in new tab or windowhttps://youtu.be/4KS4e3ILKOw

CDFW Photos. Top Photo: The four-woman forensics team.

Categories: Wildlife Research
  • September 19, 2018

Green sea turtle on top of blue tarp secured by poles in shallow water
Ready for release.

Green sea turtle in shallow water shoreline heading out into open water. People with surf boards standing in water in background.
Heading back out to the open water.

CDFW Senior Environmental Scientist Mike Harris is credited with the rescue of a green sea turtle that was unintentionally caught from a pier in Morro Bay.

Harris and the Morro Bay Harbor Patrol responded to a report of the hooked turtle on Aug. 17, after Harris was alerted by a friend in the area.

He arrived to find the angler had carefully secured the turtle and was waiting for help. He noticed the fishing line with a swivel was sticking out of the turtle’s mouth and determined the hook could not be easily removed.

Harris shares work space in Morro Bay with The Marine Mammal Center (TMMC) triage facility, positioning himself well for marine wildlife response. Coincidentally, the TMMC Morro Bay veterinarian is Heather Harris, Mike’s wife, who happens to be an expert on sea turtles.

“She was the first person I called,” he said.

Veterinarian Harris stabilized the turtle and determined it needed surgery since the hook was lodged deep in its throat. Not having the proper equipment and supplies for this type of surgery at the triage site, Heather reached out to colleagues at the Aquarium of the Pacific in Long Beach to arrange for the required care.

The green sea turtle was transported that afternoon and underwent surgery for the hook removal the same day. The hook was successfully removed, the turtle was provided antibiotic treatment and, after several weeks of rehabilitation, was released back into the wild on September 18th.

Harris said the rescue was made possible by the great working relationship between CDFW, TMMC, other agencies and the public.

“Over the past 20 years, I’ve built a connection with the community,” said Harris. “Whether it’s whales, dolphins or sea otters, the public and local agencies often call me to report these types of wildlife events.”

Harris has worked in the Morro Bay area for more than 27 years and is one of two sea otter biologists that work for CDFW’s Office of Spill Prevention and Response (CDFW-OSPR) Marine Wildlife Veterinary Care and Research Center (MWVCRC).

The MWVCRC is a one-of-a-kind lab built in 1997 and focuses on the rescue, rehabilitation and research of oiled marine wildlife, with emphasis on sea otters. California lawmakers created OSPR in 1991 due to several major spills including the Exxon Valdez in 1989. The lab is funded by a fee on petroleum entering California refineries.

Photos Copyright Aquarium of The Pacific. Top Photo: Rescued green sea turtle.

Categories: General
  • August 29, 2018

Person holding large net with oiled duck on boat
Staff and volunteers of the Oiled Wildlife Care Network, managed by UC Davis, capture oiled wildlife using nets.

Laboratory with table covered in blue towel with oiled bird wrapped in towel held by man wearing white coveralls, white hat, glasses, and purple gloves. Woman also standing with mask, white coveralls, blue gloves, holding a clipboard and pen.
Staff of the Oiled Wildlife Care Network examine a bird collected from the Nov 7 2007 oil spill in San Francisco Bay.

Close up of person wearing purple gloves holding oiled cormorant with one hand on head and other hand on beak
Staff and volunteers of the Oiled Wildlife Care Network wash oil from a bird.

Young boy in yellow boots, black pants, red and gray jacket and man wearing blue jeans, blue jacket and glasses holding blue box tipped out toward water with bird looking out from box.
Staff and volunteers release rehabilitated wildlife.
 

Scientists from the California Department of Fish and Wildlife (CDFW) and University of California, Davis have published an opinion essay that advocates rehabilitation and release, rather than euthanization, of animals injured by oil spills. The essay, entitled “Life and Death: How Should We Respond to Oiled Wildlife?” can be found in the June 2018 issue of the Journal of Fish and Wildlife Management.

CDFW Environmental Scientist Laird Henkel and Dr. Michael Ziccardi, director of the Oiled Wildlife Care Network at the UC Davis School of Veterinary Medicine, argue that a coordinated effort to attempt rehabilitation of oiled wildlife is warranted on scientific, financial and ethical grounds.

Efforts to clean birds and mammals oiled by spills are not only publicly expected in California, but also mandated by laws enacted in the early 1990s. However, some critics have argued that rehabilitation is a waste of resources and that the most responsible action is to immediately euthanize impacted animals.

In their paper, Henkel and Ziccardi cite scientific studies that show oiled animals often survive just as well as non-oiled control animals, and that euthanasia should only be considered for animals unlikely to return to normal function after rehabilitation.

The scientists assert that the costs for wildlife rehabilitation are typically a very small portion of overall oil spill response costs. Costs are also typically independent of post-spill funds secured to restore impacted natural resources — the cost of cleaning wildlife does not reduce the post-spill restoration work.

From an ethical standpoint, Henkel and Ziccardi note that some people consider individual animals to have intrinsic value, and that as consumers of petroleum products, we have an obligation to reduce suffering and mitigate injuries from spills associated with the production, distribution, and use of petroleum products.

The scientists cite public safety and legal issues as additional rationale for rehabilitation. They contend that members of the public, untrained to care for animals, will attempt to help oiled animals on their own if professional organizations do not. They further assert that legislation protecting the environment is often catalyzed by public outrage over seeing oiled wildlife.

The essay can be found online at the link opens in new windowJournal of Fish and Wildlife Management website.

For more information on oiled wildlife rehabilitation in California, visit the link opens in new windowOiled Wildlife Care Network, or CDFW’s Office of Spill Prevention and Response.

All photos courtesy of University of California, Davis. Cover: One of many oiled ducks being soaped and treated.

Categories: General