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Person

Susan Knowles

Veterinary Pathologist

National Wildlife Health Center

Email: sknowles@usgs.gov
Office Phone: 608-270-2462
Fax: 608-270-2415
ORCID: 0000-0002-0254-6491

Location
6006 Schroeder Road
Madison , WI 53711-6223
US

Supervisor: David S Blehert
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These data sets are is a compilation of bird and environmental samples obtained from 6 sites in Maricopa County, Arizona on the dates shown. Sites were only visited and sampled if they had Rosy-cheeked lovebirds coming to bird feeders at the location and with the permission of the property owner. Two swab samples were obtained from each captured bird and 3 swab samples were collected from the environment at each site. Each sample was tested by PCR for Chlamydia psittaci, Psittacine Circovirus genotype 1 [PCV-1]), and Psittacine Circovirus genotype 2 (PCV-2) and, for appropriate samples (love birds and environmental samples) and where enough sample material remained for PBFD virus Pathotype 2.
During 2002−2015 we examined the causes of mortality in beachcast northern sea otters (Enhydra lutris kenyoni) collected from the coasts of Washington and Oregon states. A total of 333 moribund or dead sea otters were reported through opportunistic observations and 93 otter carcasses were collected for necropsy. Retrieved carcasses received a full diagnostic evaluation to determine cause of death when carcass condition permitted. Otter stranding reports were received from the entire Washington coast and northern Oregon coast, but carcasses located near areas populated by humans were most often in suitable condition for cause of death determination. Data in this release include basic demographic information on the...
We reviewed pathological findings and to a lesser extent epidemiological data from 70 free-ranging columbiforms naturally infected with Pigeon paramyxovirus-1 (PPMV-1) from 25 different PPMV-1 mortality events in columbiforms in the USA. In a subset of 17 birds from 10 of the studied outbreaks, we carried out immunohistochemistry targeting PPMV-1 nucleoprotein to determine the tissue distribution of the virus.
As harmful algal blooms (HABs) increase in magnitude and duration worldwide, they are becoming an expanding threat to marine wildlife. Over the past decade, domoic acid (DA) and saxitoxin (STX) have been increasingly problematic bicoastally in the United States. We investigated pooled seabird mortality data from opportunistic sampling events between 2007-2018, across three states, to examine the patterns and role of DA and STX in seabird mortality events from the continental United States. Patterns in DA and STX levels and affected tissue type were reviewed, and two specific accounts of localized and pervasive event types were examined. There has been increased toxin detection with expanded tissue testing during...
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We experimentally challenged wild Mexican free-tailed bats (TABR) with SARS-CoV-2 to determine the susceptibility, reservoir potential, and population impacts of infection in this species. Of nine bats oronasally inoculated with SARS-CoV-2, five became infected and orally excreted moderate amounts of virus for up to 18 days post inoculation. These five subjects all seroconverted and cleared the virus before the end of the study with no obvious clinical signs of disease. We additionally found no evidence of viral transmission to uninoculated subjects. These results indicate that while TABR are susceptible to SARS-CoV-2 infection, infection of wild populations of TABR would not likely cause mortality.
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