Valerie Shearn-Bochsler
Science and Products
Necropsy & Pathology
The Necropsy and Pathology services are performed by board-certified veterinary pathologists and necropsy technical staff whose principal role is to determine the cause of death for animals submitted to the USGS National Wildlife Health Center.
Investigation of the 2018 thick-billed murre (Uria lomvia) die-off on St. Lawrence Island rules out food shortage as the cause
Die-offs of seabirds in Alaska have occurred with increased frequency since 2015. In 2018, on St. Lawrence Island, seabirds were reported washing up dead on beaches starting in late May, peaking in June, and continuing until early August. The cause of death was documented to be starvation, leading to the conclusion that a severe food shortage was...
Will, Alexis; Thiebot, Jean-Baptiste; Ip, Hon S.; Shoogukwruk, Panguk; Annogiyuk, Morgan; Takahashi, Akinori; Shearn-Bochsler, Valerie I.; Killian, Mary-Lea; Torchetti, Mia Kim; Kitaysky, Alexander Lethal infection of wild raptors with highly pathogenic avian influenza H5N8 and H5N2 viruses in the USA, 2014–15
An outbreak of highly pathogenic avian influenza (HPAI) led to heavy losses of poultry in commercial farms in North America in 2014–15. Enhanced surveillance by virologists and pathologists at the US Geological Survey National Wildlife Health Center and its partners resulted in the identification of lethal infections with clade 2.3.4.4 subgroup...
Knowles, Susan; Shearn-Bochsler, Valerie I.; Ip, Hon S. High costs of infection: Alphavirus infection reduces digestive function and bone and feather growth in nestling house sparrows (Passer domesticus)
Increasingly, ecoimmunology studies aim to use relevant pathogen exposure to examine the impacts of infection on physiological processes in wild animals. Alphaviruses are arthropod-borne, single-stranded RNA (ssRNA) viruses (“arboviruses”) responsible for millions of cases of human illnesses each year. Buggy Creek virus (BCRV) is a unique...
Fassbinder-Orth, Carol A.; Killpack, Tess L.; Goto, Dylan S.; Rainwater, Ellecia L.; Shearn-Bochsler, Valerie I. Chlamydia psittaci in feral Rosy-faced Lovebirds (Agapornis roseicollis) and other backyard birds in Maricopa County, Arizona
In 2013, a mortality event of nonnative, feral Rosy-faced Lovebirds (Agapornis roseicollis) in residential backyards in Maricopa County, Arizona, US was attributed to infection with Chlamydia psittaci. In June 2014, additional mortality occurred in the same region. Accordingly, in August 2014 we sampled live lovebirds and sympatric bird...
Dusek, Robert J.; Justice-Allen, Anne; Bodenstein, Barbara; Knowles, Susan; Grear, Daniel A.; Adams, Laura; Levy, Craig; Yaglom, Haley D.; Shearn-Bochsler, Valerie I.; Ciembor, Paula; Gregory, Christopher R.; Pesti, Denise; Ritchie, Branson W. West Nile virus infection in American singer canaries: An experimental model in a highly susceptible avian species
This study investigated the susceptibility of American singer canaries (Serinus canaria) to West Nile virus (WNV) infection. Adult canaries were inoculated with 105, 102, and 101plaque forming units (PFU) of WNV. All birds became infected and mortality occurred by 5 days postinoculation. The load of viral RNA as determined by RT-qPCR was dose...
Hofmeister, Erik K.; Lund, Melissa; Shearn-Bochsler, Valerie I. Grass is not always greener: Rodenticide exposure of a threatened species near marijuana growing operations
ObjectiveMarijuana (Cannabis spp.) growing operations (MGO) in California have increased substantially since the mid-1990s. One environmental side-effect of MGOs is the extensive use of anticoagulant rodenticides (AR) to prevent damage to marijuana plants caused by wild rodents. In association with a long-term demographic study, we report on...
Franklin, Alan B.; Carlson, Peter C.; Rex, Angela; Rockweit, Jeremy T.; Garza, David; Culhane, Emily; Volker, Steven F; Dusek, Robert J.; Shearn-Bochsler, Valerie I.; Gabriel, Mourad W.; Horak, Katherine E. Mortality trends in northern sea otters (Enhydra lutris kenyoni) collected from the coasts of Washington and Oregon (2002–15)
During 2002−15 we examined the causes of mortality in a population of northern sea otters (Enhydra lutris kenyoni). Beachcast sea otters were collected primarily from the coast of Washington. Although there are no permanent sea otter residents in Oregon, several beachcast otters were collected from the Oregon coast. Infectious diseases were the...
White, C. LeAnn; Lankau, Emily W. ; Lynch, Deanna; Knowles, Susan; Schuler, Krysten L.; Dubey, Jitender P.; Shearn-Bochsler, Valerie I.; Isidoro Ayza, Marcos; Thomas, Nancy J. Novel dermatophilosis and concurrent amyloidosis in Sanderlings (Calidris alba) from Louisiana, USA
We observed Sanderlings (Calidris alba) with facial growths in coastal Louisiana, US during summer of 2016. Severe lesions were associated with lethargy and lack of a flight response. We determined that the skin growth etiology was a bacterium of the genus Dermatophilus, rarely reported infecting birds. Sanderlings also exhibited severe...
Shearn-Bochsler, Valerie I.; Schulz, Jessica L.; Dobbs, Robert C.; Lorch, Jeffrey M.; Waddle, J. Hardin; Grear, Daniel A. Experimental infection of common eider ducklings with Wellfleet Bay virus, a newly characterized orthomyxovirus
Wellfleet Bay virus (WFBV), a novel orthomyxovirus in the genus Quaranjavirus, was first isolated in 2006 from carcasses of common eider (Somateria mollissima) during a mortality event in Wellfleet Bay (Barnstable County, Massachusetts, USA) and has since been repeatedly isolated during recurrent mortality events in this location. Hepatic,...
Shearn-Bochsler, Valerie I.; Ip, Hon S.; Ballmann, Anne; Hall, Jeffrey S.; Allison, Andrew B.; Ballard, Jennifer R.; Ellis, Julie C.; Cook, Robert; Gibbs, Samantha E. J.; Dwyer, Chris P. Mass mortality attributed to acanthocephaliasis at a Gull-billed Tern (Gelochelidon nilotica) colony in coastal California
From 12 May 2013 to 29 May 2013, the Gull-billed Tern (Gelochelidon nilotica) colony at the San Diego Bay National Wildlife Refuge, California, experienced a mass die-off of at least 92 adults, representing 71–92% of the breeding population on the US west coast. Cause of death was determined to be peritonitis due to perforations of the intestine...
Patton, Robert T.; Goodenough, Katharine S.; De La Cruz, Susan; Nevins, HannahRose M.; Cole, Rebecca A.; Bodenstein, Barbara; Shearn-Bochsler, Valerie I.; Collins, Brian; Beck, Jessie; Sadowski, Matthew; Takekawa, John Y. Potential for water borne and invertebrate transmission of West Nile virus in the Great Salt Lake, Utah
In November and December of 2013, a large mortality event involving 15,000 - 20,000 eared grebes (Podiceps nigricollis) occurred at the Great Salt Lake (GSL), UT. The onset of the outbreak in grebes was followed by a mortality event in > 86 bald eagles (Haliaeetus leucocephalus). During the die-off, West Nile virus (WNV) was detected by RT-PCR...
Lund, Melissa; Shearn-Bochsler, Valerie I.; Dusek, Robert J.; Shivers, Jan; Hofmeister, Erik K. Susceptibility and antibody response of the laboratory model zebra finch (Taeniopygia guttata) to West Nile Virus
Since the introduction of West Nile virus (WNV) into North America in 1999 a number of passerine bird species have been found to play a role in the amplification of the virus. Arbovirus surveillance, observational studies and experimental studies have implicated passerine birds (songbirds, e.g., crows, American robins, house sparrows, and house...
Hofmeister, Erik K.; Lund, Melissa; Shearn-Bochsler, Valerie I.; Balakrishnan, Christopher N.
Pathology Case of the Month - Red Wolf
Case History: An adult female 21.6-kg red wolf (Canis rufus) was found dead along the side of a road in North Carolina in November 2012.
Pathology Case of the Month - Timber Wolf
Case History: An aged adult male 36 kg Timber Wolf was found dead in the winter of 2003 in northern Wisconsin, USA. The weather was clear and cold, with low temperatures in the negative single digits. Wolf and coyote tracks were present in the area.
Pathology Case of the Month - Common Eider
Case: A juvenile male 1.46-kg Common Eider (Somateria mollissima) was found dead on a beach in Massachusetts, USA.
Pathology Case of the Month - Gyrfalcon
Case History: A captive, adult male, 930-g Gyrfalcon (Falco rusticolus) was found dead in its enclosure on December 8, 2014.