Here’s a look at some of the work being done by UC Davis One Health Institute faculty members. Sticking with the theme, these projects all focus on a variety of birds and bats. Visit the OHI website to see what other species we’re working with throughout the world.

Determining Genetic Diversity of Hummingbirds to Conserve Species


The Ernest Lab Hummingbird Health Program focuses on examining diseases that afflict California hummingbirds, of which there are about seven species. The lab is led by Holly Ernest, a wildlife veterinarian and ecological geneticist for the UC Davis Wildlife Health Center.

The lab is determining genetic diversity, population structure and taxonomic status through genomic analysis. Veterinary and graduate students and technicians in the lab developed DNA-based disease diagnostic tests (analyzing DNA from pathogens) and molecular tools to determine whether a hummingbird is a species hybrid. 

Holly's group is actively involved with citizen science and public bird conservation education. Members of the public – from kids to senior citizens – help them at their hummingbird field sites throughout California to capture and examine the birds for diseases. Holly is one of very few licensed Master bird banders in the U.S. specializing in hummingbirds, and she helps teach banders-in-training.

Future plans: Full genome analysis to determine species differences. To conserve species, you must be able to identify them.

The collaborative hummingbird work is being done with other veterinarians and professors, such as Dr. Lisa Tell, Dr. Leslie Woods and others. Holly's team is also working with state, federal and NGO collaborators like the Hummingbird Monitoring Network.

The two publications above are in memory of Dr. Loreto Godoy, a Chilean veterinarian and one of Holly's PhD students, who was killed in an auto accident in June of 2013. An endowed graduate student fellowship is being created in her name.  More than $19,000 in donations and pledges have been secured–just a little further to get to $25,000 for the endowment. You can help fundraise for the scholarship at the links below:

Contact Holly Ernest at

Defining a New Subspecies of the Endangered Great Gray Owl

There are only a few hundred Great Gray Owls remaining in the Sierra Nevadas. The Ernest Wildlife Genetics and Population Health Lab has been working on health and conservation genetics of this endangered species, which is the largest owl in the world by length. (Not by weight—they’re quite slim).

They have a new paper in press defining a new subspecies of Great Gray Owl—the genetically distinct Yosemite population. This paper is the product of collaboration with Josh Hull, who did his PhD and post-doc work on the owl in Holly’s lab and is now Recovery Division Chief at the Sacramento Office of the US Fish and Wildlife Service and an assistant adjunct professor in UC Davis Animal Science.

Joe Medley and Eric Jepsen, two other coauthors, completed their Avian Science Master's degree work in the Ernest Lab, with a focus on the Great Gray Owl. They also partnered with the USDA Forest Service, UC Davis Wildlife and Fisheries Biology Department and field owl biologists in Canada and the United States.

Contact Holly Ernest at

Toxicity From Spent Lead Shot in Argentina

Waterfowl hunting in northeastern Argentina is locally encouraged because some dominant duck species are considered agricultural pests. Furthermore, duck hunting has become a profitable industry, and over the years Argentina has turned into an international hotspot that attracts hunters from all over the world.

Based on licenses sold, there are about 4,000 hunter days per waterfowl season, which at the current quotas suggests at least 100,000 ducks hunted in Argentina from May to August, all of them with lead ammunition, the only available option.

Our research measures lead levels in several duck species, as well as in the soil, water and vegetation. We focused on the wetlands and rice fields near the provinces of Santa Fe and Corrientes, both of which are used extensively by waterfowl and hunters. We’ve sampled five commonly hunted species of ducks. The figure on the right depicts the amount of ingested lead pellets found in each species in our study. We also tracked heightened levels of lead in the livers, bones and blood of ducks. We found strong positive association between morphological abnormalities and lead levels in blood.

We also found lead in the blood of yellow anacondas – which prey on waterfowl -- within the area of our duck study. All of the anacondas we sampled in a separate, remote location were negative. More study is needed here, however.

The amount of spent lead shot discharged into wetlands of Argentina yearly is unknown. However, the findings in our study strongly suggest that lead poisoning from spent shot is a risk for local waterfowl and other species.

Taking a One Health approach, we have engaged a wide range of stakeholders, including hunters, outfitters, government agencies, local communities and schools. Our ultimate goal is to contribute to the ban of lead shot in Argentina, which would serve as an example for the rest of Latin America. 

Since we began our project in 2007, Cordoba province has completely banned lead shot in wetlands, Santa Fe has reduced hunting quotas by 50 percent when lead shot is used and Buenos Aires province has established regulations to begin the banning process. This work is being done in conjunction with Wildlife Conservation Society, and two Argentina universities, Universidad Nacional del Centro de la Provincia de Buenos Aires, and Universidad Nacional del Litoral, and is funded by Morris Animal Foundation.

Publications:  Recent & Chronic Exposure of Wild Ducks to Lead in Human-Modified Wetlands in Santa Fe Province, Argentina  

Article in press for the journal, Ecotoxicology and Environmental Safety: Lead gunshot pellet ingestion and tissue lead levels in wild ducks from Argentina hunting hotspots, by Ferreyra, Romano, Beldomenico, Caselli, Correa and Uhart. 

Contact Marcela Uhart at  

Quantifying Release Readiness for Oiled Wildlife

After oiled birds are rehabilitated, it’s important to evaluate their health to ensure that they’re ready to be released back to the wild. One such measurement is Fibrinogen--an acute phase protein found in all vertebrates.

Fibrinogen levels tend to demonstrably rise after an inflammatory response and can remain high if chronic inflammation persists. A reliable measurement of fibrinogen levels could help scientists determine when a bird is ready for release.

The current quantitative measurement of fibrinogen is the modified Clauss method, but it requires that large samples be taken, then frozen and transported on ice. The constraints of the above-described method limit its utility.

Our study tested three different methodologies on eight rehabilitated wild brown pelicans and 13 healthy captive African penguins. The conclusion was that, despite the drawbacks, the Clauss method is the best option for avian fibrinogen determination. Read the details of the study in the poster below. 

Note: Our collaboration with the UC Davis Clinical Pathology Lab validated the use of the modified Clauss method on birds.

Contact Christine Fiorello at

West Nile Virus and Burrowing Owls

West Nile Virus emerged in the United States in the late 1990s, causing sometimes fatal disease in humans, horses, and a variety of bird species. 

The burrowing owl is a species of special concern in California, but its susceptibility to West Nile Virus is unknown. Despite the known susceptibility of owls to West Nile, the California Raptor Center at UC Davis has received surprisingly few with the disease. It is critical to gain an understanding of the virus's impact on owl species in the state, not only for the conservation of the burrowing owl, but also to protect the entire ecosystem that would be affected by the loss of these predators.

Drs. Christine Fiorello and Michelle Hawkins propose to quantify the exposure of the more common owl species during a period of high West Nile Virus activity in the region, as well as that of the more threatened species during the whole history of the presence of the virus in the state. Results from this proposed study will begin to answer crucial questions regarding the exposure of owls to West Nile Virus in the Yolo County area of California. 


Chlamydia psittaci Prevalence in Over-Winters Birds vs. Migratory Birds in California  

Recently, some birds of prey have been presented to the California Raptor Center at UC Davis for clinical signs associated with Chlamydia psittaci, a bacteria that can cause significant disease in birds and people. 

Dr. Michelle Hawkins, Director of the California Raptor Center, in collaboration with the Golden Gate Raptor Observatory and US Fish and Wildlife, are studying whether the disease is more prevalent in the over-winter populations of birds in the Northern California valley, or whether the disease is also found in migratory birds passing through this region. Dr. Hawkins is also studying the clinical and pathologic findings associated with this disease in Northern California raptors.

Contact Michelle Hawkins at

The California Raptor Center's Successful Events

The Condor's Shadow: The film explores the efforts taken by biologists, zookeepers and scientists to pull the California condor back from the brink of extinction. More than 100 people attended the screening on Sept. 28, which was followed by a Q&A with the filmmaker. 

Fall Open House: Hundreds flowed through the center on Oct. 19. Volunteers gave presentations while attendees strolled amongst the rehabilitated hawks, falcons eagles and owls. Special thanks to Whole Foods Market Davis and Mendocino Brewing Company for supporting the center by providing complimentary appetizers and beer tasting. We very much appreciate it. 

You can support the California Raptor Center, too.