Avian health and disease, ecology of landbirds, beak deformities in Alaska (“avian keratin disorder”), anatomy and structure of keratinized tissues, wildlife pathology.
Professional Experience
2012 - Present Research Wildlife Biologist, USGS Alaska Science Center, Anchorage, AK
2005 - 2012 Wildlife Biologist, USGS Alaska Science Center, Anchorage, AK
2003 - 2005 Teaching Assistant, Western Washington University, Bellingham, WA
2001 Volunteer Field Assistant, Wild Dog Research Camp, Okavango Delta, Botswana
2000 - 2002 Bioscience Technician, USGS Alaska Science Center, Anchorage, AK
1999 Research Assistant, Wildlife Conservation Society, Haines, AK
1998 Field Research Assistant, U.S. Fish and Wildlife Service, Anchorage, AK
1997 - 1998 Research Assistant, University of Arizona, Tucson, AZ
Education and Certifications
Ph.D. 2012 University of Alaska, Fairbanks, AK Biology and Wildlife
M.A. 2005 Western Washington University, Bellingham, WA English/Creative Nonfiction
B.S. 2000 University of Arizona, Tucson, AZ Ecology and Evolution
B.A. 2000 University of Arizona, Tucson, AZ Gender Studies
Affiliations and Memberships*
American Ornithological Society
Boreal Partners in Flight
The Wildlife Society
Wildlife Disease Association
Science and Products
Wildlife Disease and Environmental Health in Alaska
Harmful Algal Bloom Toxins in Alaska Seabirds
Background of Beak Deformity Research
Species Affected by Beak Deformities
Physical Description of Beak Deformities
Prevalence, Distribution and Timing of Beak Deformities in Birds
Beak Deformity's Effects on Birds
Possible Causes for Beak Deformities
Literature Cited for Beak Deformities
Links Related to Beak Deformity Research
Beak Deformities in Landbirds
Landbird Research in Alaska
Cryptosporidium and Giardia Occurrence Data in Wildlife from Arctic Alaska, 2012-2017
USGS National Wildlife Health Center necropsy results to determine cause of illness/death for seabirds collected in Alaska from January 1, 2017 through December 31, 2021
Serological Survey Data for Francisella tularensis and Brucella spp. Exposure in Wildlife on the Arctic Coastal Plain of Alaska
Tissue Concentrations and Congener Profiles of Harmful Algal Toxins in Seabirds, Forage Fish, and Other Organisms
Dataset: Acute oral toxicity and tissue residues of saxitoxin in the mallard (Anas platyrhynchos)
Data Associated with Poecivirus Testing of Individual Birds with Beak Deformities
Data Associated with Algal Toxin Testing of Seabirds from the Bering and Chukchi Seas, 2017
Data Associated With Algal Toxin Testing of Common Murres (Uria aalge) and Forage Fish in Alaska, 2015-2017
Blood Parasite Infection Data from Northwestern Crows (Corvus caurinus), Alaska, 2007-2008
Serological Data on Influenza A from Birds and Mammals on the Arctic Coastal Plain of Northern Alaska, 2011-2017
Genetic data associated with avian keratin disorder and Poecivirus in black-capped chickadees, Alaska, 2016-2017
Giardia and Cryptosporidium in resident wildlife species in Arctic Alaska
Partnering in search of answers: Seabird die-offs in the Bering and Chukchi Seas
A serological survey of Francisella tularensis exposure in wildlife on the Arctic Coastal Plain of Alaska
Paralytic shellfish toxins associated with Arctic Tern mortalities in Alaska
Harmful algal blooms in the Alaskan Arctic: An emerging threat as oceans warm
Acute oral toxicity and tissue residues of saxitoxin in the mallard (Anas platyrhynchos)
Alaska Landbird Conservation Plan
U.S. Geological Survey Arctic ecosystem assessments
Investigation of algal toxins in a multispecies seabird die-off in the Bering and Chukchi seas
Poecivirus is present in individuals with beak deformities in seven species of North American birds
Cryptic and extensive hybridization between ancient lineages of American crows
Algal toxins in Alaskan seabirds: Evaluating the role of saxitoxin and domoic acid in a large-scale die-off of Common Murres
Science and Products
- Science
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Wildlife Disease and Environmental Health in Alaska
Environmental health is defined by connections between the physical environment, ecological health, and human health. Current research within the U.S. Geological Survey (USGS) recognizes the importance of this integrated research philosophy, which includes study of disease and pollutants as they pertain to both wildlife and humans. Due to its key geographic location and significant wildlife...Harmful Algal Bloom Toxins in Alaska Seabirds
Elevated ocean temperatures are linked to the development of harmful algal blooms (HABs). Toxins from these blooms may pose health threats to marine organisms, including seabirds. Since 2015, the USGS has worked with a variety of stakeholders to develop testing methods and research projects to better understand the geographic extent, timing and impacts of algal toxins in Alaska marine ecosystems...Background of Beak Deformity Research
Large numbers of Black-capped Chickadees with abnormal beaks were reported in south-central Alaska in the late 1990s. More recently, similar beak deformities have appeared in other species throughout the state. At least 30 Alaskan bird species are affected and the geographic extent of the problem appears to be growing. In addition to Alaskan observations, we have received increasing numbers of...Species Affected by Beak Deformities
At least 30 Alaskan bird species are affected and the geographic extent of the problem appears to be growing. In addition to Alaskan observations, we have received increasing numbers of reports from other parts of North America and Europe.Physical Description of Beak Deformities
The most commonly observed physical abnormalities among Alaskan birds are overgrown or crossed beaks. The severity of the deformities varies, ranging from a nearly indiscernible “overbite” to beaks that are more than double their normal length. The upper and lower parts of the beak are also frequently crossed or gapped.Prevalence, Distribution and Timing of Beak Deformities in Birds
The rates of beak deformities documented in Black-capped Chickadees and Northwestern Crows in Alaska are the highest ever recorded within a wild bird population anywhere.Beak Deformity's Effects on Birds
Birds with beak deformities often have difficulty foraging and preening, and may not be able to keep themselves warm and well-fed during cold winter months. Although some birds with beak deformities breed successfully, they typically encounter more challenges than normal birds.Possible Causes for Beak Deformities
Beak deformities can be caused by a variety of factors, including contaminants, nutritional deficiencies, disease, parasites, blunt trauma, or genetic abnormalities. We recently identified a novel picornavirus (Poecivirus) in Black-capped Chickadees with avian keratin disorder (AKD). Our results suggest that Poecivirus is the most likely factor responsible for beak deformities in Alaskan birds...Literature Cited for Beak Deformities
Literature Cited in the Beak Deformity web pagesLinks Related to Beak Deformity Research
Links, videos and news articles related to beak deformity researchBeak Deformities in Landbirds
Over the past 20 years, Alaskans have witnessed a startling increase of beak deformities among Black-capped Chickadees and other species of resident birds. This disease, called avian keratin disorder (AKD), is characterized by debilitating beak overgrowth and other abnormalities of keratinized tissues. Affected birds have difficulty feeding and preening, and may suffer high rates of mortality.Landbird Research in Alaska
On this page, learn about USGS work on Beak Deformities and Boreal Partners in Flight. - Data
Cryptosporidium and Giardia Occurrence Data in Wildlife from Arctic Alaska, 2012-2017
This dataset consists of one table with sample collection locations and results of screening resident wildlife for Cryptosporidium and Giardia in the Alaskan Arctic, 2012-2017. We analyzed feces collected from polar bear, Pacific walrus, Arctic fox, and caribou with MERIFLUOR direct immunofluorescence assay to determine the presence of Cryptosporidium oocysts and Giardia cysts.USGS National Wildlife Health Center necropsy results to determine cause of illness/death for seabirds collected in Alaska from January 1, 2017 through December 31, 2021
Summary of Bering and Chukchi Seas seabird necropsies, 2017-2021. More than 14,000 dead seabirds were reported and a total of 117 carcasses were examined. 92 cases had emaciation identified as the Cause Of Death (COD), seven cases where COD was undetermined, and 17 cases where COD was determined as "Other", which included predation, trauma, encephalitis, peritonitis, and bacterial infection. Low PSerological Survey Data for Francisella tularensis and Brucella spp. Exposure in Wildlife on the Arctic Coastal Plain of Alaska
This dataset consists of one table with diagnostic screening results from a study of Francisella tularensis bacteria exposure in tundra-nesting geese and mammals and Brucella spp. exposure in mammals sampled from multiple locations on the Arctic Coastal Plain of Alaska, 2014-2017. The table provides sample collection and location data of geese, arctic fox, red fox, caribou, small mammal, and polarTissue Concentrations and Congener Profiles of Harmful Algal Toxins in Seabirds, Forage Fish, and Other Organisms
These data are in four tables and contain results from screening tissues of marine organisms for the presence of harmful algal bloom (HAB) toxins: saxitoxin and its related congeners (STX) and domoic acid (DA). Samples collected by USGS or submitted to our laboratory by partners or other stakeholders are screened using commercially-available enzyme linked immunosorbent assays (ELISA). A subset ofDataset: Acute oral toxicity and tissue residues of saxitoxin in the mallard (Anas platyrhynchos)
This data set is composed of data collected from an experimental study inoculating mallard ducks (Anas platyrhynchos) with Saxitoxin and associated control ducks. Data includes the specific of inoculation, observational behavioral data, daily weights, dosing, results of inoculation, testing of samples collected throughout the study, and necropsy results.Data Associated with Poecivirus Testing of Individual Birds with Beak Deformities
This data set is comprised of two tables, one with results of poecivirus screening of tissues from six North American avian species using PCR followed by Sanger sequencing in addition to unbiased metagenomic sequencing, the second lists the names and sequences of primers used.Data Associated with Algal Toxin Testing of Seabirds from the Bering and Chukchi Seas, 2017
This data set is comprised of three tables with results of algal toxin screening for saxitoxin and domoic acid. We used enzyme-linked immunosorbent assay (ELISA) and high-performance liquid chromatography (HPLC) to screen seabirds in the Bering and Chukchi Seas, 2017.Data Associated With Algal Toxin Testing of Common Murres (Uria aalge) and Forage Fish in Alaska, 2015-2017
This data set is comprised of two tables with results of algal toxin screening for saxitoxin and domoic acid. We used enzyme-linked immunosorbent assay (ELISA) and high-performance liquid chromatography (HPLC) to screen seabirds, forage fish, and marine invertebrates from the Gulf of Alaska, 2015-2017.Blood Parasite Infection Data from Northwestern Crows (Corvus caurinus), Alaska, 2007-2008
This data set consists of two tables associated with a study of Haemosporidian parasite infection in Northwestern Crows (Corvus caurinus) sampled at six locations throughout southcentral and southeast Alaska in 2007-2008. The first table contains species, location, banding, and morphometric data for all samples. The second table contains results from heamosporidian parasite screening of crow bloodSerological Data on Influenza A from Birds and Mammals on the Arctic Coastal Plain of Northern Alaska, 2011-2017
These data (in two spreadsheets) are the results of screening for influenza A viruses (IAV) in blood from wild animals that utilize the Arctic region of Alaska. 758 blood samples from nine wildlife species (3 mammal, 6 waterbird) were collected in Arctic Alaska, 2011-2017. Two different tests were used and the results are presented in separate spreadsheets. All blood samples were screened for IAVGenetic data associated with avian keratin disorder and Poecivirus in black-capped chickadees, Alaska, 2016-2017
This dataset contains results of genetic screening for Poecivirus from samples of black-capped chickadees (BCCH; Poecile atricapillus) with and without clinical signs of avian keratin disorder (AKD). Data include information on detection/non-detection of the virus in tissue collected with buccal swabs, cloacal swabs, blood samples, and fecal samples from up to 124 individuals between 2015 and 2017 - Multimedia
- Publications
Filter Total Items: 43
Giardia and Cryptosporidium in resident wildlife species in Arctic Alaska
Giardia and Cryptosporidium are zoonotic protozoan parasites that can infect humans and other taxa, including wildlife, often causing gastrointestinal illness. Both have been identified as One Health priorities in the Arctic, where climate change is expected to influence the distribution of many wildlife and zoonotic diseases, but little is known about their prevalence in local wildlife. To help fAuthorsCaroline R. Van Hemert, Lora Ballweber, David R. Sinnett, Todd C. Atwood, Anthony S. Fischbach, David Gustine, Kristy PabiloniaPartnering in search of answers: Seabird die-offs in the Bering and Chukchi Seas
Prior to 2015, seabird die-offs in Alaskan waters were rare; they typically occurred in mid-winter, linked to epizootic disease events or above-average ocean temperatures associated with strong El Nino-Southern Oscillation events (Bodenstein et al. 2015, Jones et al. 2019, Romano et al. 2020). Since 2015, the U.S. Fish and Wildlife Service (USFWS) has monitored mortality events that have become anAuthorsRobb A. S. Kaler, Gay Sheffield, S Backensto, Jackie Lindsey, T. Jones, J. Parrish, B Ahmasuk, Barbara Bodenstein, Robert J. Dusek, Caroline R. Van Hemert, Matthew M. Smith, P SchwalenbergA serological survey of Francisella tularensis exposure in wildlife on the Arctic Coastal Plain of Alaska
Tularemia is an infectious zoonotic disease caused by one of several subspecies of Francisella tularensis bacteria. Infections by F. tularensis are common throughout the northern hemisphere and have been detected in more than 250 wildlife species. In Alaska, US, where the pathogen was first identified in 1938, studies have identified F. tularensis antibodies in a diverse suite of taxa, including iAuthorsMatthew M. Smith, Caroline R. Van Hemert, Todd C. Atwood, David R. Sinnett, Jerry W. Hupp, Brandt W Meixell, David D. Gustine, Layne G. Adams, Andrew M. RameyParalytic shellfish toxins associated with Arctic Tern mortalities in Alaska
Harmful algal blooms produce biotoxins that can injure or kill fish, wildlife, and humans. These blooms occur naturally but have intensified in many locations globally due to recent climatic changes, including ocean warming. Such changes are especially pronounced in northern regions, where the effects of paralytic shellfish toxins (PSTs) on marine wildlife are of growing concern. In Alaska, seabirAuthorsCaroline R. Van Hemert, John Harley, Gwen Baluss, Matthew M. Smith, Robert J. Dusek, Julia S. Lankton, D. Ransom Hardison, Sarah K. Schoen, Robert KalerHarmful algal blooms in the Alaskan Arctic: An emerging threat as oceans warm
Harmful algal blooms (HABs) present an emerging threat to human and ecosystem health in the Alaskan Arctic. Two HAB toxins are of concern in the region: saxitoxins (STXs), a family of compounds produced by the dinoflagellate Alexandrium catenella, and domoic acid (DA), produced by multiple species in the diatom genus Pseudo-nitzschia. These potent neurotoxins cause paralytic and amnesic shellfishAuthorsDonald Anderson, Evangeline Fachon, Katherine Hubbard, Kathi Lefebvre, Peigen Lin, Robert Pickart, Mindy Richlen, Gay Sheffield, Caroline R. Van HemertAcute oral toxicity and tissue residues of saxitoxin in the mallard (Anas platyrhynchos)
Since 2014, widespread, annual mortality events involving multiple species of seabirds have occurred in the Gulf of Alaska, Bering Sea, and Chukchi Sea. Among these die-offs, emaciation was a common finding with starvation often identified as the cause of death. However, saxitoxin (STX) was detected in many carcasses, indicating exposure of these seabirds to STX in the marine environment. Few dataAuthorsRobert J. Dusek, Matthew M. Smith, Caroline R. Van Hemert, Valerie I. Shearn-Bochsler, Sherwood Hall, Clark D. Ridge, Ransome Hardison, Robert Kaler, Barbara Bodenstein, Erik K. Hofmeister, Jeffrey S. HallAlaska Landbird Conservation Plan
Alaska is a land of extremes. The diversity of its avifauna reflects the heterogeneity of its landscape, with more than 500 species of birds recorded in the state. Species inhabiting primarily terrestrial habitats, known collectively as landbirds, constitute the largest and most ecologically diverse component of the Alaska avifauna. Habitats used by landbirds range from temperate rainforests in soAuthorsTravis L. Booms, Melissa N. Cady, Cheryl A. Carrothers, Lucas H. DeCicco, Maureen L. de Zeeuw, Melanie J. Flamme, Julie Hagelin, Colleen M. Handel, James A. Johnson, Matthew D. Kirchoff, Michelle L. Kissling, Stephen B. Lewis, Steven M. Matsuoka, Debora A. Nigro, Deborah E. Perkins, Heather M. Renner, Susan E. Savage, Kristine M. Sowl, Susan M. Sharbaugh, Iain J Stenhouse, Caroline R. Van HemertU.S. Geological Survey Arctic ecosystem assessments
The U.S Geological Survey (USGS) conducts natural hazard and resource assessments of the Earth’s ecosystems and the response of those ecosystems to environmental change, human activities, and land use. Arctic regions of Alaska are important for cultural and economic sustainability and host a wide variety of wildlife species, many of which are of conservation and management interest to the U.S. DepAuthorsJohn M. Pearce, Caroline R. Van HemertInvestigation of algal toxins in a multispecies seabird die-off in the Bering and Chukchi seas
Between 2014 and 2017, widespread seabird mortality events were documented annually in the Bering and Chukchi seas, concurrent with dramatic reductions of sea ice, warmer than average ocean temperatures, and rapid shifts in marine ecosystems. Among other changes in the marine environment, harmful algal blooms (HABs) that produce the neurotoxins saxitoxin (STX) and domoic acid (DA) have been identiAuthorsCaroline R. Van Hemert, Robert J. Dusek, Matthew M. Smith, Robert Kaler, Gay Sheffield, Lauren M. Divine, Kathy J. Kuletz, Susan Knowles, Julia S. Lankton, D. Ransom Hardison, R. Wayne Litaker, Timothy Jones, Hillary K. Burgess, Julia K. ParrishPoecivirus is present in individuals with beak deformities in seven species of North American birds
Avian keratin disorder (AKD), a disease of unknown etiology characterized by debilitating beak overgrowth, has increasingly affected wild bird populations since the 1990s. A novel picornavirus, poecivirus, is closely correlated with disease status in Black-capped Chickadees (Poecile atricapillus) in Alaska. However, our knowledge of the relationship between poecivirus and beak deformities in otherAuthorsMaxine Zylberberg, Caroline R. Van Hemert, Colleen M. Handel, Rachel Liu, Joseph L. DeRisiCryptic and extensive hybridization between ancient lineages of American crows
Most species and therefore most hybrid zones have historically been defined using phenotypic characters. However, both speciation and hybridization can occur with negligible morphological differentiation. Recently developed genomic tools provide the means to better understand cryptic speciation and hybridization. The Northwestern Crow (Corvus caurinus) and American Crow (Corvus brachyrhynchos) areAuthorsDavid Slager, Kevin Epperly, Renee Ha, Sievert Rohwer, Christopher W. Woodall, Caroline R. Van Hemert, John KlickaAlgal toxins in Alaskan seabirds: Evaluating the role of saxitoxin and domoic acid in a large-scale die-off of Common Murres
Elevated seawater temperatures are linked to the development of harmful algal blooms (HABs), which pose a growing threat to marine birds and other wildlife. During late 2015 and early 2016, a massive die-off of Common Murres (Uria algae; hereafter, murres) was observed in the Gulf of Alaska coincident with a strong marine heat wave. Previous studies have documented illness and death among seabirdsAuthorsCaroline R. Van Hemert, Sarah K. Schoen, R. Wayne Litaker, Matthew M. Smith, Mayumi L. Arimitsu, John F. Piatt, William C. Holland, Ransom Hardison, John M. Pearce - News
*Disclaimer: Listing outside positions with professional scientific organizations on this Staff Profile are for informational purposes only and do not constitute an endorsement of those professional scientific organizations or their activities by the USGS, Department of the Interior, or U.S. Government