Photographs from a Little Brown Bat (Myotis lucifugus) found dead in Montana, USA (A, B, D). (A) Multiple foci of depigmentation (arrowheads) measuring up to 3 mm in diameter are present on the patagia. (B) Under ultraviolet light, there is a single pinpoint focus of orange fluorescence (arrowhead) and multiple pinpoint foci of blue fluorescence (arrow).
Susan Knowles
Susan Knowles is a Wildlife Veterinary Pathologist at the National Wildlife Health Center.
She earned a Doctorate of Veterinary Medicine from the Virginia-Maryland Regional College of Veterinary Medicine and completed a residency in veterinary pathology and earned a Doctorate in Veterinary Pathology from the University of Georgia. She is a Diplomate of the American College of Veterinary Pathologists. She joined the Center in 2013 and her interests include wildlife, aquatic, invertebrate and toxicologic pathology, and pathogen discovery. Before joining the Center, she gained a variety of experience in and around her native Maryland, performing research on shortnose sturgeon, serving as a Veterinary Officer in the United States Public Health Service stationed at the National Institutes of Health, and working as a Natural Resources Biologist for the Maryland Department of Natural Resources where she was a member of the Fish and Wildlife Health Program and served as the Marine Mammal and Sea Turtle Stranding Coordinator for the state.
Professional Experience
2013 – Present Wildlife Veterinary Pathologist, U.S. Geological Survey, National Wildlife Health Center, Madison, WI
2006 – 2013 Resident of Anatomic and Aquatic Pathology and Graduate Assistant, Department of Veterinary Pathology, University of Georgia, Athens, GA
2003 – 2003 Veterinary Officer, Junior COSTEP, United States Public Health Service, Rockville, MD stationed at NIH, Diagnostic and Research Services Branch, Veterinary Pathology, Bethesda, MD
1996 – 2002 Natural Resources Biologist, Maryland Marine Mammal & Sea Turtle Stranding Coordinator, Fish and Wildlife Health Program, Maryland Department of Natural Resources, Cooperative Oxford Laboratory, Oxford, MD
1995 – 1996 Histology Technician, Maryland Department of Natural Resources, Cooperative Oxford Laboratory, Oxford, MD
Education and Certifications
Ph.D. Veterinary Pathology, University of Georgia, 2013
D.V.M., Virginia-Maryland Regional College of Veterinary Medicine, 2006
B.S. Biology, Bucknell University, 1995
Affiliations and Memberships*
Diplomate American College of Veterinary Pathologists
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.
Native Freshwater Mussel Health
2015 Sonora Mud Turtles
Little Brown Bats (Myotis lucifugus) weights and Ct values for SARS-CoV-2 Infection challenge
2018 Embarrass River Microsporidia
2011 and 2017 Pika Pathology Colorado
Metabolomic analysis of pheasantshell mussel (Ortmanniana pectorosa; Order Unionida) from a mass mortality event in the Clinch River, Virginia and Tennessee, USA
Paranannizziopsis spp. associated with skin lesions in wild snakes in North America and development of a real-time PCR assay for rapid detection of the fungus in clinical samples
Experimental infection of Mexican free-tailed bats (Tadarida brasiliensis) with SARS-CoV-2
A Novel Gonadotropic Microsporidian Parasite (Microsporidium clinchi n. sp.) Infecting a Declining Population of Pheasantshell Mussels (Actinonaias pectorosa) (Unioinidae) from the Clinch River, USA
Data from pathology of Lagovirus europaeus GI.2/RHDV2/b (rabbit hemorrhagic disease virus 2) in native North American lagomorphs
Domoic acid and saxitoxin in seabirds from California and Rhode Island 2015-2017
Bayou Sauvage NWR (LA) Haul Trail Snake Mortality, 2015-2017
Necropsy reference number and summary collection information for Washington state population of northern sea otters examined during 1989-2010
Photographs from a Little Brown Bat (Myotis lucifugus) found dead in Montana, USA (A, B, D). (A) Multiple foci of depigmentation (arrowheads) measuring up to 3 mm in diameter are present on the patagia. (B) Under ultraviolet light, there is a single pinpoint focus of orange fluorescence (arrowhead) and multiple pinpoint foci of blue fluorescence (arrow).
Photomicrographs from little brown bats, one with square-eared anomaly, found dead in Montana, USA.
linkPhotomicrographs from an unaffected Little Brown Bat (M. lucifugus; A-B) and Little Brown Bat found dead in Montana, USA with the square-eared anomaly (C-E). Periodic Acid Schiff-Hematoxylin. (A) Pinna of an unaffected Little Brown Bat showing the epidermis (e and arrow), dermis (d) and central elastic cartilage plate (c).
Photomicrographs from little brown bats, one with square-eared anomaly, found dead in Montana, USA.
linkPhotomicrographs from an unaffected Little Brown Bat (M. lucifugus; A-B) and Little Brown Bat found dead in Montana, USA with the square-eared anomaly (C-E). Periodic Acid Schiff-Hematoxylin. (A) Pinna of an unaffected Little Brown Bat showing the epidermis (e and arrow), dermis (d) and central elastic cartilage plate (c).
Photomicrographs of the plagiopatagium from a Little Brown Bat (Myotis lucifugus) captured live in Wyoming, U.S.A. (A) Adult nematodes (asterisks) are present in the dermis. They are filled with larval nematodes (arrowhead). The overlying epidermis is hyperplastic (arrow). H&E stain.
Photomicrographs of the plagiopatagium from a Little Brown Bat (Myotis lucifugus) captured live in Wyoming, U.S.A. (A) Adult nematodes (asterisks) are present in the dermis. They are filled with larval nematodes (arrowhead). The overlying epidermis is hyperplastic (arrow). H&E stain.
Photomicrographs from a Mallard Duck (Anas platyrhynchos) found dead in Missouri, U.S.A. (A) The glomerular mesangium (asterisk) is expanded by amorphous, eosinophilic, acellular material. H&E stain. (B) Tubules in medullary cones are often surrounded by amorphous, eosinophilic, acellular material. H&E stain.
Photomicrographs from a Mallard Duck (Anas platyrhynchos) found dead in Missouri, U.S.A. (A) The glomerular mesangium (asterisk) is expanded by amorphous, eosinophilic, acellular material. H&E stain. (B) Tubules in medullary cones are often surrounded by amorphous, eosinophilic, acellular material. H&E stain.
Photomicrographs from a Common Grackle (Quiscalus quiscula) found dead in Ohio, U.S.A. H&E stains. (A) Longitudinal (arrow) and cross sections (arrowheads) of microfilariae in a pulmonary blood vessel. (B) Microfilariae (arrows) within a parabronchus. (C) Microfilaria (arrow) within the cerebellar parenchyma with no associated inflammation.
Photomicrographs from a Common Grackle (Quiscalus quiscula) found dead in Ohio, U.S.A. H&E stains. (A) Longitudinal (arrow) and cross sections (arrowheads) of microfilariae in a pulmonary blood vessel. (B) Microfilariae (arrows) within a parabronchus. (C) Microfilaria (arrow) within the cerebellar parenchyma with no associated inflammation.
Photomicrographs from the intestine of a Brazilian Free-tailed Bat (Tadarida brasiliensis) found dead in Texas, USA.
Photomicrographs from the intestine of a Brazilian Free-tailed Bat (Tadarida brasiliensis) found dead in Texas, USA.
Photomicrographs from a muskrat (Ondatra zibethicus) found dead in Ohio, USA. (A) Within the liver, there is a cluster of nematode eggs with light brown to eosinophilic bi-operculated shells (arrowheads) with radial striations (arrow) that contain eosinophilic flocculent material (asterisk). H&E stain.
Photomicrographs from a muskrat (Ondatra zibethicus) found dead in Ohio, USA. (A) Within the liver, there is a cluster of nematode eggs with light brown to eosinophilic bi-operculated shells (arrowheads) with radial striations (arrow) that contain eosinophilic flocculent material (asterisk). H&E stain.
Photomicrographs with H&E stain from a Bald Eagle (Haliaeetus leucocephalus) found dead in Wisconsin, USA
linkPhotomicrographs with H&E stain from a Bald Eagle (Haliaeetus leucocephalus) found dead in Wisconsin, USA. (A) Hepatocytes contain one or more variably-sized intracytoplasmic round, clear vacuoles (arrowheads). (B) Bile ducts are plugged with bile (asterisk). (C) Multifocally in the brainstem, there are small perivascular hemorrhages (arrows).
Photomicrographs with H&E stain from a Bald Eagle (Haliaeetus leucocephalus) found dead in Wisconsin, USA
linkPhotomicrographs with H&E stain from a Bald Eagle (Haliaeetus leucocephalus) found dead in Wisconsin, USA. (A) Hepatocytes contain one or more variably-sized intracytoplasmic round, clear vacuoles (arrowheads). (B) Bile ducts are plugged with bile (asterisk). (C) Multifocally in the brainstem, there are small perivascular hemorrhages (arrows).
Photomicrographs from a Northern Shoveler (Spatula clypeata) from Utah, USA. H&E stain. (A) The air sac epithelium is replaced by or covered with a thick layer of fibrin admixed with heterophils and fewer macrophages and eosinophilic and cellular necrotic debris (*).
Photomicrographs from a Northern Shoveler (Spatula clypeata) from Utah, USA. H&E stain. (A) The air sac epithelium is replaced by or covered with a thick layer of fibrin admixed with heterophils and fewer macrophages and eosinophilic and cellular necrotic debris (*).
Photographs from red crossbills (Loxia curvirostra; A, C) and American goldfinches (Spinus tristis; B, D) from Montana, U.S.A. (A) A large yellow/tan plaque (asterisk) is present on the mucosal surface of the crop. (B) White seed-like plaques (arrow) are present on the mucosal surface of the crop.
Photographs from red crossbills (Loxia curvirostra; A, C) and American goldfinches (Spinus tristis; B, D) from Montana, U.S.A. (A) A large yellow/tan plaque (asterisk) is present on the mucosal surface of the crop. (B) White seed-like plaques (arrow) are present on the mucosal surface of the crop.
Photographs from a raccoon (Procyon lotor) from Arizona, US. (A) Large tan nematodes (arrowheads) are present within the subcutaneous tissue and muscle fascia in the distal right forelimb. (B) Closer view of the distal right forelimb showing the large tan nematodes (arrowheads).
Photographs from a raccoon (Procyon lotor) from Arizona, US. (A) Large tan nematodes (arrowheads) are present within the subcutaneous tissue and muscle fascia in the distal right forelimb. (B) Closer view of the distal right forelimb showing the large tan nematodes (arrowheads).
Photomicrographs from a big brown bat (Eptesicus fuscus) from Wisconsin, USA. H&E stain. (A) Low magnification of a cross section through the nares showing nasal cavity (*), oral mucosa (arrowhead), and haired skin (arrow). (B) Higher magnification showing a normal hair follicle (arrow) surrounded by sebaceous glands.
Photomicrographs from a big brown bat (Eptesicus fuscus) from Wisconsin, USA. H&E stain. (A) Low magnification of a cross section through the nares showing nasal cavity (*), oral mucosa (arrowhead), and haired skin (arrow). (B) Higher magnification showing a normal hair follicle (arrow) surrounded by sebaceous glands.
Photographs (A &B) from a Canada Goose (Branta canadensis) found dead in Minnesota, US. (A) The esophagus is dilated and impacted with a large amount of duckweed (arrows). (B) Forty #9 lead pellets are recovered from the ventriculus. (C) Photograph from a Bald Eagle
Photographs (A &B) from a Canada Goose (Branta canadensis) found dead in Minnesota, US. (A) The esophagus is dilated and impacted with a large amount of duckweed (arrows). (B) Forty #9 lead pellets are recovered from the ventriculus. (C) Photograph from a Bald Eagle
Bacteriological analysis of unionid hemolymph collected from freshwater mussel populations in the Pacific northwestern United States
Freshwater mussel viromes increase rapidly in diversity and abundance when hosts are released from captivity into the wild
Little brown bats (Myotis lucifugus) are resistant to SARS-CoV-2 infection
Hirsutonosema embarrassi n. gen. n. sp. (Phylum Microsporidia) in the Ovary of Mucket (Actinonaias ligamentina), Plain Pocketbook (Lampsilis cardium), and Fatmucket (Lampsilis siliquoidea) (Unionidae) from the Embarrass River, Wisconsin, USA
Retrospective review of the pathology of American pikas
Paranannizziopsis spp. infections in wild snakes and a qPCR assay for detection of the fungus
Mussel mass mortality in the Clinch River, USA: Metabolomics detects affected pathways and biomarkers of stress
Pathology and infectious agents of unionid mussels: A primer for pathologists in disease surveillance and investigation of mortality events
A bacteriological comparison of the hemolymph from healthy and moribund unionid mussel populations in the upper Midwestern U.S.A. prompts the development of diagnostic assays to detect Yokenella regensburgei
Further bacteriological analysis of annual Pheasantshell (Actinonaias pectorosa) mussel mortality events in the Clinch River (Virginia/Tennessee), USA, reveals a consistent association with Yokenella Regensburgei
Experimental infection of Mexican free-tailed bats (Tadarida brasiliensis) with SARS-CoV-2
Freshwater mussels show elevated viral richness and intensity during a mortality event
Non-USGS Publications**
**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.
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.
Native Freshwater Mussel Health
2015 Sonora Mud Turtles
Little Brown Bats (Myotis lucifugus) weights and Ct values for SARS-CoV-2 Infection challenge
2018 Embarrass River Microsporidia
2011 and 2017 Pika Pathology Colorado
Metabolomic analysis of pheasantshell mussel (Ortmanniana pectorosa; Order Unionida) from a mass mortality event in the Clinch River, Virginia and Tennessee, USA
Paranannizziopsis spp. associated with skin lesions in wild snakes in North America and development of a real-time PCR assay for rapid detection of the fungus in clinical samples
Experimental infection of Mexican free-tailed bats (Tadarida brasiliensis) with SARS-CoV-2
A Novel Gonadotropic Microsporidian Parasite (Microsporidium clinchi n. sp.) Infecting a Declining Population of Pheasantshell Mussels (Actinonaias pectorosa) (Unioinidae) from the Clinch River, USA
Data from pathology of Lagovirus europaeus GI.2/RHDV2/b (rabbit hemorrhagic disease virus 2) in native North American lagomorphs
Domoic acid and saxitoxin in seabirds from California and Rhode Island 2015-2017
Bayou Sauvage NWR (LA) Haul Trail Snake Mortality, 2015-2017
Necropsy reference number and summary collection information for Washington state population of northern sea otters examined during 1989-2010
Photographs from a Little Brown Bat (Myotis lucifugus) found dead in Montana, USA (A, B, D). (A) Multiple foci of depigmentation (arrowheads) measuring up to 3 mm in diameter are present on the patagia. (B) Under ultraviolet light, there is a single pinpoint focus of orange fluorescence (arrowhead) and multiple pinpoint foci of blue fluorescence (arrow).
Photographs from a Little Brown Bat (Myotis lucifugus) found dead in Montana, USA (A, B, D). (A) Multiple foci of depigmentation (arrowheads) measuring up to 3 mm in diameter are present on the patagia. (B) Under ultraviolet light, there is a single pinpoint focus of orange fluorescence (arrowhead) and multiple pinpoint foci of blue fluorescence (arrow).
Photomicrographs from little brown bats, one with square-eared anomaly, found dead in Montana, USA.
linkPhotomicrographs from an unaffected Little Brown Bat (M. lucifugus; A-B) and Little Brown Bat found dead in Montana, USA with the square-eared anomaly (C-E). Periodic Acid Schiff-Hematoxylin. (A) Pinna of an unaffected Little Brown Bat showing the epidermis (e and arrow), dermis (d) and central elastic cartilage plate (c).
Photomicrographs from little brown bats, one with square-eared anomaly, found dead in Montana, USA.
linkPhotomicrographs from an unaffected Little Brown Bat (M. lucifugus; A-B) and Little Brown Bat found dead in Montana, USA with the square-eared anomaly (C-E). Periodic Acid Schiff-Hematoxylin. (A) Pinna of an unaffected Little Brown Bat showing the epidermis (e and arrow), dermis (d) and central elastic cartilage plate (c).
Photomicrographs of the plagiopatagium from a Little Brown Bat (Myotis lucifugus) captured live in Wyoming, U.S.A. (A) Adult nematodes (asterisks) are present in the dermis. They are filled with larval nematodes (arrowhead). The overlying epidermis is hyperplastic (arrow). H&E stain.
Photomicrographs of the plagiopatagium from a Little Brown Bat (Myotis lucifugus) captured live in Wyoming, U.S.A. (A) Adult nematodes (asterisks) are present in the dermis. They are filled with larval nematodes (arrowhead). The overlying epidermis is hyperplastic (arrow). H&E stain.
Photomicrographs from a Mallard Duck (Anas platyrhynchos) found dead in Missouri, U.S.A. (A) The glomerular mesangium (asterisk) is expanded by amorphous, eosinophilic, acellular material. H&E stain. (B) Tubules in medullary cones are often surrounded by amorphous, eosinophilic, acellular material. H&E stain.
Photomicrographs from a Mallard Duck (Anas platyrhynchos) found dead in Missouri, U.S.A. (A) The glomerular mesangium (asterisk) is expanded by amorphous, eosinophilic, acellular material. H&E stain. (B) Tubules in medullary cones are often surrounded by amorphous, eosinophilic, acellular material. H&E stain.
Photomicrographs from a Common Grackle (Quiscalus quiscula) found dead in Ohio, U.S.A. H&E stains. (A) Longitudinal (arrow) and cross sections (arrowheads) of microfilariae in a pulmonary blood vessel. (B) Microfilariae (arrows) within a parabronchus. (C) Microfilaria (arrow) within the cerebellar parenchyma with no associated inflammation.
Photomicrographs from a Common Grackle (Quiscalus quiscula) found dead in Ohio, U.S.A. H&E stains. (A) Longitudinal (arrow) and cross sections (arrowheads) of microfilariae in a pulmonary blood vessel. (B) Microfilariae (arrows) within a parabronchus. (C) Microfilaria (arrow) within the cerebellar parenchyma with no associated inflammation.
Photomicrographs from the intestine of a Brazilian Free-tailed Bat (Tadarida brasiliensis) found dead in Texas, USA.
Photomicrographs from the intestine of a Brazilian Free-tailed Bat (Tadarida brasiliensis) found dead in Texas, USA.
Photomicrographs from a muskrat (Ondatra zibethicus) found dead in Ohio, USA. (A) Within the liver, there is a cluster of nematode eggs with light brown to eosinophilic bi-operculated shells (arrowheads) with radial striations (arrow) that contain eosinophilic flocculent material (asterisk). H&E stain.
Photomicrographs from a muskrat (Ondatra zibethicus) found dead in Ohio, USA. (A) Within the liver, there is a cluster of nematode eggs with light brown to eosinophilic bi-operculated shells (arrowheads) with radial striations (arrow) that contain eosinophilic flocculent material (asterisk). H&E stain.
Photomicrographs with H&E stain from a Bald Eagle (Haliaeetus leucocephalus) found dead in Wisconsin, USA
linkPhotomicrographs with H&E stain from a Bald Eagle (Haliaeetus leucocephalus) found dead in Wisconsin, USA. (A) Hepatocytes contain one or more variably-sized intracytoplasmic round, clear vacuoles (arrowheads). (B) Bile ducts are plugged with bile (asterisk). (C) Multifocally in the brainstem, there are small perivascular hemorrhages (arrows).
Photomicrographs with H&E stain from a Bald Eagle (Haliaeetus leucocephalus) found dead in Wisconsin, USA
linkPhotomicrographs with H&E stain from a Bald Eagle (Haliaeetus leucocephalus) found dead in Wisconsin, USA. (A) Hepatocytes contain one or more variably-sized intracytoplasmic round, clear vacuoles (arrowheads). (B) Bile ducts are plugged with bile (asterisk). (C) Multifocally in the brainstem, there are small perivascular hemorrhages (arrows).
Photomicrographs from a Northern Shoveler (Spatula clypeata) from Utah, USA. H&E stain. (A) The air sac epithelium is replaced by or covered with a thick layer of fibrin admixed with heterophils and fewer macrophages and eosinophilic and cellular necrotic debris (*).
Photomicrographs from a Northern Shoveler (Spatula clypeata) from Utah, USA. H&E stain. (A) The air sac epithelium is replaced by or covered with a thick layer of fibrin admixed with heterophils and fewer macrophages and eosinophilic and cellular necrotic debris (*).
Photographs from red crossbills (Loxia curvirostra; A, C) and American goldfinches (Spinus tristis; B, D) from Montana, U.S.A. (A) A large yellow/tan plaque (asterisk) is present on the mucosal surface of the crop. (B) White seed-like plaques (arrow) are present on the mucosal surface of the crop.
Photographs from red crossbills (Loxia curvirostra; A, C) and American goldfinches (Spinus tristis; B, D) from Montana, U.S.A. (A) A large yellow/tan plaque (asterisk) is present on the mucosal surface of the crop. (B) White seed-like plaques (arrow) are present on the mucosal surface of the crop.
Photographs from a raccoon (Procyon lotor) from Arizona, US. (A) Large tan nematodes (arrowheads) are present within the subcutaneous tissue and muscle fascia in the distal right forelimb. (B) Closer view of the distal right forelimb showing the large tan nematodes (arrowheads).
Photographs from a raccoon (Procyon lotor) from Arizona, US. (A) Large tan nematodes (arrowheads) are present within the subcutaneous tissue and muscle fascia in the distal right forelimb. (B) Closer view of the distal right forelimb showing the large tan nematodes (arrowheads).
Photomicrographs from a big brown bat (Eptesicus fuscus) from Wisconsin, USA. H&E stain. (A) Low magnification of a cross section through the nares showing nasal cavity (*), oral mucosa (arrowhead), and haired skin (arrow). (B) Higher magnification showing a normal hair follicle (arrow) surrounded by sebaceous glands.
Photomicrographs from a big brown bat (Eptesicus fuscus) from Wisconsin, USA. H&E stain. (A) Low magnification of a cross section through the nares showing nasal cavity (*), oral mucosa (arrowhead), and haired skin (arrow). (B) Higher magnification showing a normal hair follicle (arrow) surrounded by sebaceous glands.
Photographs (A &B) from a Canada Goose (Branta canadensis) found dead in Minnesota, US. (A) The esophagus is dilated and impacted with a large amount of duckweed (arrows). (B) Forty #9 lead pellets are recovered from the ventriculus. (C) Photograph from a Bald Eagle
Photographs (A &B) from a Canada Goose (Branta canadensis) found dead in Minnesota, US. (A) The esophagus is dilated and impacted with a large amount of duckweed (arrows). (B) Forty #9 lead pellets are recovered from the ventriculus. (C) Photograph from a Bald Eagle
Bacteriological analysis of unionid hemolymph collected from freshwater mussel populations in the Pacific northwestern United States
Freshwater mussel viromes increase rapidly in diversity and abundance when hosts are released from captivity into the wild
Little brown bats (Myotis lucifugus) are resistant to SARS-CoV-2 infection
Hirsutonosema embarrassi n. gen. n. sp. (Phylum Microsporidia) in the Ovary of Mucket (Actinonaias ligamentina), Plain Pocketbook (Lampsilis cardium), and Fatmucket (Lampsilis siliquoidea) (Unionidae) from the Embarrass River, Wisconsin, USA
Retrospective review of the pathology of American pikas
Paranannizziopsis spp. infections in wild snakes and a qPCR assay for detection of the fungus
Mussel mass mortality in the Clinch River, USA: Metabolomics detects affected pathways and biomarkers of stress
Pathology and infectious agents of unionid mussels: A primer for pathologists in disease surveillance and investigation of mortality events
A bacteriological comparison of the hemolymph from healthy and moribund unionid mussel populations in the upper Midwestern U.S.A. prompts the development of diagnostic assays to detect Yokenella regensburgei
Further bacteriological analysis of annual Pheasantshell (Actinonaias pectorosa) mussel mortality events in the Clinch River (Virginia/Tennessee), USA, reveals a consistent association with Yokenella Regensburgei
Experimental infection of Mexican free-tailed bats (Tadarida brasiliensis) with SARS-CoV-2
Freshwater mussels show elevated viral richness and intensity during a mortality event
Non-USGS Publications**
**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.
*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