I am an Avian Ecologist at the U.S. Geological Survey Forest and Rangeland Ecosystem Science Center in Corvallis, Oregon. My research focuses on identifying and understanding environmental threats primarily to avian populations and providing sound scientific research to implement conservation solutions.
My work focuses on understanding the physiological responses of wildlife to environmental contaminants and landscape-scale stressors. I specialize in field-based ecological studies to assess the impacts of stressors (lead, mercury, prey availability, rodenticides) on the behavior and reproduction of avian species. Additionally, my laboratory-based studies examine the physiological responses of a variety of wildlife (birds, amphibians, and fishes) to a wide array of environmental contaminants.
Professional Experience
2012 – Present: Ecologist, USGS Forest and Rangeland Ecosystem Science Center, Corvallis, OR
2008–2012: Post-doctoral Research Scholar, University of California, Davis & USGS Western Ecological Research Center, Davis, CA
Education and Certifications
Ph.D., Integrative Biology, Florida Atlantic University, Boca Raton, FL (2008)
M.S., Fisheries & Wildlife Science, North Carolina State University, Raleigh, NC (2003)
B.S., Environmental Science, University of Lethbridge, Lethbridge, AB, Canada (1999)
Affiliations and Memberships*
2019-2022: Associate Editor, Avian Research
2014-2016: Associate Editor, Journal of Wildlife Management
2012-2015: Associate Editor, Wetlands
Science and Products
Contaminant Ecology Research Team (FRESC)
The FRESC Contaminant Ecology research program evaluates the distribution, movement, and ecological effects of environmental contaminants across the landscape and strives to provide relevant science in support of natural resource conservation, management, and decision making.
If you are unable to access or download a product, email fresc_outreach@usgs.gov a request, including the full citation, or call (541) 750-1030.
Anticoagulant rodenticide concentrations in blood and tissue of California condors and turkey vultures (ver. 2.0, May 2023)
The dataset includes specifics on liver tissue and blood plasma anticoagulant rodenticide concentrations measured using high-performance liquid chromatography-tandem mass spectrometry.
Anticoagulant rodenticide exposure in Barred Owls (Strix varia) collected in Washington and Oregon 2015-2017
This dataset includes anticoagulant rodenticide (AR) screening results of 40 Barred Owls (Strix varia) collected in forested landscapes of Washington and Oregon from 2015-2017. Liver tissue was collected from each owl and screened for exposure to eight AR compounds, including 4 first-generation ARs (warfarin, diphacinone, chlorophacinone, and coumachlor), and 4 second-generation ARs (brodifacoum,
Pacific Northwest Avian Scavenger Lead and Mercury Dataset, 2012-2016
The dataset includes the bird species, region where sampled, sampling site, capture location, mercury concentration in whole blood, lead concentration in whole blood, sulfur stable isotope concentration in blood plasma, carbon isotope concentration in blood plasma, whole blood ALAD activity, and fecal corticosterone concentrations.
Summary of Total Mercury Concentrations in Dragonfly Larvae, Western Mosquitofish, and Tree Swallow Eggs Collected from Cosumnes River Preserve 2011 2013
The Cosumnes River Preserve in the Californias Central Valley contains a mosaic of managed wetlands where conditions may promote high levels of methylmercury bioaccumulation. In order to document potential environmental health risk in these wetlands due to mercury, we analyzed dragonfly larvae, western mosquitofish, and tree swallow eggs collected from wetlands and rice fields of the Preserve from
Fluctuating asymmetry in waterbirds in relation to mercury exposure
The dataset includes the bird species, sex, mercury concentration in breast feathers and whole blood, and the composite measure of fluctuating asymmetry. Statistical models were developed for each species to analyze the relationship between mercury exposure in either breast feathers or whole blood and the composite measure of fluctuating asymmetry, while accounting for the sex of each bird.
Bullet fragments in Belding's ground squirrels in Oregon and California in 2014-2015
The dataset includes specifics on fragments of bullets recovered from shot Belding's ground squirrels from Oregon and California. Ground squirrels were radiographed and then we used ImageJ software to count and measure the area of those bullet fragments. A subset of shot carcasses were then digested and bullet fragments were recovered. Statistical models were developed to predict either the number
If you are unable to access or download a product, email fresc_outreach@usgs.gov a request, including the full citation, or call (541) 750-1030.
Filter Total Items: 35
Anticoagulant rodenticides are associated with increased stress and reduced body condition of avian scavengers in the Pacific Northwest
Anticoagulant rodenticides (AR) have been used globally to manage commensal rodents for decades. However their application has also resulted in primary, secondary, and tertiary poisoning in wildlife. Widespread exposure to ARs (primarily second generation ARs; SGARs) in raptors and avian scavengers has triggered considerable conservation concern over their potential effects on populations. To iden
Authors
Garth Herring, Collin Eagles-Smith, Jeremy A. Buck
A 37 K SNP array for the management and conservation of Golden Eagles (Aquila chrysaetos)
We describe the development of a custom 37 K Affymetrix Axiom myDesign single nucleotide polymorphism (SNP) array for a culturally and ecologically important apex predator, the golden eagle (Aquila chrysaetos). Using this SNP array, we performed population genomic analysis on 154 individuals of known natal localities and detected three genetic clusters that we designated as Taiga/High Arctic, Grea
Authors
Megan E. Judkins, Gary W. Roemer, Brian Millsap, Joseph G. Barnes, Bryan E. Bedrosian, Stephen L. Clarke, Robert Domenech, Garth Herring, Myles Lamont, Brian W. Smith, Dale W. Stahlecker, Matthew J. Stuber, Wesley C. Warren, Ronald A. Van Den Bussche
Collateral damage: Anticoagulant rodenticides pose threats to California condors
Anticoagulant rodenticides (ARs) are widespread environmental contaminants that pose risks to scavenging birds because they routinely occur within their prey and can cause secondary poisoning. However, little is known about AR exposure in one of the rarest avian scavengers in the world, the California condor (Gymnogyps californianus). We assessed AR exposure in California condors and surrogate tur
Authors
Garth Herring, Collin Eagles-Smith, Rachel Wolstenholme, Alacia Welch, Chris West, Barnett A. Rattner
Mercury exposure of tidal marsh songbirds in the northeastern United States and its association with nest survival
The biogeochemistry of tidal marsh sediments facilitates the transformation of mercury (Hg) into the biologically available form methylmercury (MeHg), resulting in elevated Hg exposures to tidal marsh wildlife. Saltmarsh and Acadian Nelson’s sparrows (Ammospiza caudacutua and A. nelsoni subvirgatus, respectively) exclusively inhabit tidal marshes, potentially experiencing elevated risk to Hg expos
Authors
Katherine J Ruskin, Garth Herring, Collin Eagles-Smith, Alyssa B. Eiklor, Chris S Elphick, Matthew A. Etterson, Chrisopher B. Field, Rebecca A. Longnecker, Adrienne I. Kovach, W Greg Shriver, James F. Walsh, Brian J. Olsen
Small mammal shooting as a conduit for lead exposure in avian scavengers
Lead (Pb) exposure is a widespread wildlife conservation threat. Although commonly associated with Pb-based ammunition from big-game hunting, small mammals (e.g., ground squirrels) shot for recreational or pest-management purposes represent a potentially important Pb vector in agricultural regions. We measured the responses of avian scavengers to pest-shooting events and examined their Pb exposure
Authors
Garth Herring, Collin Eagles-Smith, John Goodell, Jeremy A. Buck, James Willacker
The lead (Pb) lining of agriculture‐related subsidies: enhanced Golden Eagle growth rates tempered by Pb exposure
Supplementary food resources (e.g., subsidies) associated with agriculture can benefit wildlife species, increasing predictability and availability of food. Avian scavengers including raptors often utilize subsidies associated with both recreational hunting and pest shooting on agricultural lands. However, these subsidies can contain lead (Pb) fragments if they are culled with Pb‐based ammunition,
Authors
Garth Herring, Collin Eagles-Smith, Jeremy A. Buck, Alyssa E. Shiel, Chris R. Vennum, Colleen Emery, Branden L. Johnson, David Leal, Julie A. Heath, Benjamin M Dudek, Charles R. Preston, Brian Woodbridge
Anticoagulant rodenticides in Strix owls indicate widespread exposure in west coast forests
Exposure of nontarget wildlife to anticoagulant rodenticides (AR) is a global conservation concern typically centered around urban or agricultural areas. Recently, however, the illegal use of ARs in remote forests of California, USA, has exposed sensitive predators, including the federally threatened northern spotted owl (Strix occidentalis caurina). We used congeneric barred owls (S. varia) as a
Authors
David Wiens, Krista E. Dilione, Collin A. Eagles-Smith, Garth Herring, Damon B. Lesmeister, Mourad W. Gabriel, Greta Wengert, David C. Simon
Mercury and lead exposure in avian scavengers from the Pacific Northwest suggest risks to California condors: Implications for reintroduction and recovery
Mercury (Hg) and lead (Pb) are widespread contaminants that pose risks to avian scavengers. In fact, Pb exposure is the primary factor limiting population recovery in the endangered California condor (Gymnogyps californianus) and Hg can impair avian reproduction at environmentally relevant exposures. The Pacific Northwest region of the US was historically part of the condor's native range, and eff
Authors
Garth Herring, Collin A. Eagles-Smith, Daniel E. Varland
Critically assessing the utility of portable lead analyzers for wildlife conservation
Lead (Pb) exposure in wildlife is a widespread management and conservation concern. Quantitative determination of Pb concentrations in wildlife tissues is the foundation for estimating exposure and risk. Development of low‐cost, portable instruments has improved access and cost‐effectiveness of determining Pb concentrations in blood samples, while also facilitating the ability for wildlife researc
Authors
Garth Herring, Collin A. Eagles-Smith, Bryan Bedrosian, Derek Craighead, Robert Domenech, Heiko W. Langner, Chris N. Parish, Adam Shreading, Alacia Welch, Rachel Wolstenholme
Characterizing Golden Eagle risk to lead and anticoagulant rodenticide exposure: A review
Contaminant exposure is among the many threats to Golden Eagle (Aquila chrysaetos) populations throughout North America, particularly lead poisoning and anticoagulant rodenticides (AR). These threats may act in concert with others (e.g., lead poisoning and trauma associated with striking objects) to exacerbate risk. Golden Eagles are skilled hunters but also exploit scavenging opportunities, makin
Authors
Garth Herring, Collin A. Eagles-Smith, Jeremy A. Buck
Correlates of immune defenses in golden eagle nestlings
An individual's investment in constitutive immune defenses depends on both intrinsic and extrinsic factors. We examined how Leucocytozoon parasite presence, body condition (scaled mass), heterophil-to-lymphocyte (H:L) ratio, sex, and age affected immune defenses in golden eagle (Aquila chrysaetos) nestlings from three regions: California, Oregon, and Idaho. We quantified hemolytic-complement activ
Authors
Elisabeth MacColl, Kris Vanesky, Jeremy A. Buck, Benjamin Dudek, Collin A. Eagles-Smith, Julie A. Heath, Garth Herring, Chris Vennum, Cynthia J. Downs
Mercury exposure may influence fluctuating asymmetry in waterbirds
Variation in avian bilateral symmetry can be an indicator of developmental instability in response to a variety of stressors, including environmental contaminants. The authors used composite measures of fluctuating asymmetry to examine the influence of mercury concentrations in 2 tissues on fluctuating asymmetry within 4 waterbird species. Fluctuating asymmetry increased with mercury concentration
Authors
Garth Herring, Collin A. Eagles-Smith, Joshua T. Ackerman
Non-USGS Publications**
Lyons, J.E., Collazo, J.A., Herring, G., 2015, Testing assumptions for conservation of migratory shorebirds and coastal managed wetlands: Wetlands Ecology Management, p. online, https://doi.org/10.1007/s11273-015-9477-4.
Ackerman, J.T., Herzog, M., Hartman, C.A., Herring, G., 2014, Forster’s tern chick survival in response to a managed relocation of predatory California gulls: The Journal of Wildlife Management, v. 78, no. 5, p. 818-829, https://doi.org/10.1002/jwmg.728.
Hartman, C.A., Ackerman, J.T., Herring, G., Isanhart, J., Herzog, M., 2013, Marsh wrens as bioindicators of mercury in wetlands of Great Salt Lake- do blood and feathers reflect site-specific exposure risk to bird reproduction?: Environmental Science and Technology, v. 47, no. 12, p. 6597-6605, https://doi.org/10.1021/es400910x.
Herring, G., Ackerman, J.T., Herzog, M.P., 2012, Mercury exposure may suppress baseline corticosterone levels in juvenile birds: Environmental Science and Technology, v. 46, p. 6339-6346.
Hill, N.J., Takekawa, J.Y., Ackerman, J.T., Hobson, K.A., Herring, G., Cardona, C.J., Runstadler, J.A., Boyce, W.M., 2012, Migration strategy affects avian influenza dynamics in mallards (Anas platyrhynchos): Molecular Ecology, p. online, https://doi.org/10.1111/j.1365-294X.2012.05735.x.
Herring, G., Ackerman, J.T., 2011, California gull chicks raised near colony edges have elevated stress levels: General and Comparative Endocrinology, v. 173, p. 72-77.
Herring, G., Herring, H.K., Gawlik, D.E., 2015, Social Cues and Environmental Conditions Influence Foraging Flight Distances of Breeding Wood Storks (Mycteria americana): Waterbirds, v. 38, no. 1, p. 30-39, https://doi.org/10.1675/063.038.0105.
Herring, G., Ackerman, J.T., Takekawa, J.Y., Eagles-Smith, C.A., Eadie, J.M., 2011, Identifying nest predators of American avocets (Recurvirostra americana) and black-necked stilts (Himantopus mexicanus) in San Francisco Bay, California: Southwestern Naturalist, v. 56, no. 1, p. 35-43.
Beerens, J.M., Gawlik, D.E., Herring, G., Cook, M.I., 2011, Dynamic habitat selection by two wading bird species with divergent foraging strategies in a seasonally fluctuating wetland: Auk, v. 128, p. 651-662.
Herring, G., Ackerman, J.T., Eagles-Smith, C.A., Adelsbach, T.L., Melancon, M.J., Stebbins, K.R., Hoffman, D.J., 2010, Organochlorine and PBDE concentrations in relation to cytochrome P450 activity in livers of Forster's terns (Sterna forsteri)and Caspian terns(Hydroprogne caspia),in San Francisco Bay, California: Sm, v. 58, p. 863-873.
Herring, G., Ackerman, J.T., Eagles-Smith, C.A., Takekawa, J.Y., 2010, Sexing California gulls using morphometrics and discriminant function analysis: Waterbirds, v. 33, no. 1, p. 79-85.
Herring, G., Collazo, J.A., 2009, Site characteristics and prey abundance at foraging sites used by lesser scaup (Aythya affinis)wintering in Florida: Southeastern Naturalist, v. 8, p. 363-374.
Herring, G., Gawlik, D.E., 2012, Differential physiological responses to prey availability by the great egret and white ibis: Journal of Wildlife Management, p. online, https://doi.org/10.1002/jwmg.445.
Dorn, N.J., Cook, M.I., Herring, G., Boyle, R.A., Nelson, J., Gawlik, D.E., 2011, Aquatic prey switching and urban foraging by the white ibis Eudocimus albusare determined by wetland hydrological conditions: Ibis, v. 153, p. 323-335.
Herring, G., Cook, M.I., Gawlik, D.E., Call, E.M., 2011, Food availability is expressed through physiological stress indicators in nestling white ibis- a food supplementation experiment: Functional Ecology, v. 25, p. 682-690.
Herring, G., Gawlik, D.E., 2010, Avian radio-transmitter harness wear and failure: Southeastern Naturalist, v. 9, p. 595-604.
Herring, G., Ackerman, J.T., Eagles-Smith, C.A., 2010, Embryo malposition as a potential mechanism for mercury-induced hatching failure in bird eggs: Environmental Toxicology and Chemistry, v. 29, no. 8, p. 1788-1794.
Herring, G., Gawlik, D.E., Cook, M.I., Beerens, J.M., 2010, Sensitivity of nesting great egrets (Ardea alba)and white ibises(Eudocimus albus)to reduced prey availability: Auk, v. 127, p. 660-670.
Herring, G., Gawlik, D.E., Rumbold, D.G., 2009, Feather mercury concentrations and physiological condition of great egret and white ibis nestlings in the Florida Everglades: Science of the Total Environment, v. 407, p. 2641-2649.
Herring, G., Gawlik, D.E., 2009, Stability of avian fecal corticosterone metabolite levels in frozen avian feces: Journal of Wildlife Management, v. 73, p. 1010-1013.
Dorn, N.J., Herring, G., Gawlik, D.E., 2008, Estimation of crayfish abundance and size-structure in diets of white ibis chicks: Waterbirds, v. 31, p. 417-423.
Herring, G., Gawlik, D.E., Beerens, J.M., 2008, Evaluating two new methods for capturing large wetland birds: Journal of Field Ornithology, v. 79, p. 102-110.
Herring, G., Gawlik, D.E., 2008, Potential for successful population establishment of the nonindigenous sacred ibis in the Florida Everglades: Biological Invasions, v. 10, p. 969-976.
Herring, G., Gawlik, D.E., Beerens, J.M., 2008, Sex determination for the great egret and white ibis: Waterbirds, v. 31, p. 298-303.
Marx, D.E., Hejl, S.J., Herring, G., 2008, Wintering grassland bird habitat selection following summer prescribed fire in a Texas Gulf Coast tallgrass prairie: Fire Ecology Special Issue, v. 4, no. 2, p. 46-62.
Herring, G., Gawlik, D.E., 2007, The role of stress proteins in the study of allostatic overload in birds- Use and applicability to current studies in avian ecology: The Scientific World Journal, v. 7, p. 1596-1602.
Herring, G., Collazo, J.A., 2006, Lesser scaup winter foraging and nutrient reserve acquisition in east-central Florida: Journal of Wildlife Management, v. 70, p. 1682-1689.
Rivera-Milan, F.F., Collazo, J.A., Stahala, C., Moore, W.J., Davis, A., Herring, G., Steinkamp, M., Pagliaro, R., Thompson, J.L., Bracey, W., 2005, Estimation of density and population size and recommendations for monitoring trends of Bahama parrots on Great Abaco and Great Inagua: Wildlife Society Bulletin, v. 33, p. 823-834.
Herring, G., Collazo, J.A., 2005, Habitat use, movements, and home range of wintering lesser scaup in Florida: Waterbirds, v. 28, p. 71-78.
Herring, G., Collazo, J.A., 2004, Winter survival of lesser scaup in east-central Florida: Journal of Wildlife Management, v. 68, p. 1082-1087.
Knapton, R.W., Petrie, S.A., Herring, G., 2000, Human disturbance of diving ducks on Long Point Bay, Lake Erie: Wildlife Society Bulletin, v. 28, p. 923-930.
**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
- Science
Contaminant Ecology Research Team (FRESC)
The FRESC Contaminant Ecology research program evaluates the distribution, movement, and ecological effects of environmental contaminants across the landscape and strives to provide relevant science in support of natural resource conservation, management, and decision making. - Data
If you are unable to access or download a product, email fresc_outreach@usgs.gov a request, including the full citation, or call (541) 750-1030.
Anticoagulant rodenticide concentrations in blood and tissue of California condors and turkey vultures (ver. 2.0, May 2023)
The dataset includes specifics on liver tissue and blood plasma anticoagulant rodenticide concentrations measured using high-performance liquid chromatography-tandem mass spectrometry.Anticoagulant rodenticide exposure in Barred Owls (Strix varia) collected in Washington and Oregon 2015-2017
This dataset includes anticoagulant rodenticide (AR) screening results of 40 Barred Owls (Strix varia) collected in forested landscapes of Washington and Oregon from 2015-2017. Liver tissue was collected from each owl and screened for exposure to eight AR compounds, including 4 first-generation ARs (warfarin, diphacinone, chlorophacinone, and coumachlor), and 4 second-generation ARs (brodifacoum,Pacific Northwest Avian Scavenger Lead and Mercury Dataset, 2012-2016
The dataset includes the bird species, region where sampled, sampling site, capture location, mercury concentration in whole blood, lead concentration in whole blood, sulfur stable isotope concentration in blood plasma, carbon isotope concentration in blood plasma, whole blood ALAD activity, and fecal corticosterone concentrations.Summary of Total Mercury Concentrations in Dragonfly Larvae, Western Mosquitofish, and Tree Swallow Eggs Collected from Cosumnes River Preserve 2011 2013
The Cosumnes River Preserve in the Californias Central Valley contains a mosaic of managed wetlands where conditions may promote high levels of methylmercury bioaccumulation. In order to document potential environmental health risk in these wetlands due to mercury, we analyzed dragonfly larvae, western mosquitofish, and tree swallow eggs collected from wetlands and rice fields of the Preserve fromFluctuating asymmetry in waterbirds in relation to mercury exposure
The dataset includes the bird species, sex, mercury concentration in breast feathers and whole blood, and the composite measure of fluctuating asymmetry. Statistical models were developed for each species to analyze the relationship between mercury exposure in either breast feathers or whole blood and the composite measure of fluctuating asymmetry, while accounting for the sex of each bird.Bullet fragments in Belding's ground squirrels in Oregon and California in 2014-2015
The dataset includes specifics on fragments of bullets recovered from shot Belding's ground squirrels from Oregon and California. Ground squirrels were radiographed and then we used ImageJ software to count and measure the area of those bullet fragments. A subset of shot carcasses were then digested and bullet fragments were recovered. Statistical models were developed to predict either the number - Multimedia
- Publications
If you are unable to access or download a product, email fresc_outreach@usgs.gov a request, including the full citation, or call (541) 750-1030.
Filter Total Items: 35Anticoagulant rodenticides are associated with increased stress and reduced body condition of avian scavengers in the Pacific Northwest
Anticoagulant rodenticides (AR) have been used globally to manage commensal rodents for decades. However their application has also resulted in primary, secondary, and tertiary poisoning in wildlife. Widespread exposure to ARs (primarily second generation ARs; SGARs) in raptors and avian scavengers has triggered considerable conservation concern over their potential effects on populations. To idenAuthorsGarth Herring, Collin Eagles-Smith, Jeremy A. BuckA 37 K SNP array for the management and conservation of Golden Eagles (Aquila chrysaetos)
We describe the development of a custom 37 K Affymetrix Axiom myDesign single nucleotide polymorphism (SNP) array for a culturally and ecologically important apex predator, the golden eagle (Aquila chrysaetos). Using this SNP array, we performed population genomic analysis on 154 individuals of known natal localities and detected three genetic clusters that we designated as Taiga/High Arctic, GreaAuthorsMegan E. Judkins, Gary W. Roemer, Brian Millsap, Joseph G. Barnes, Bryan E. Bedrosian, Stephen L. Clarke, Robert Domenech, Garth Herring, Myles Lamont, Brian W. Smith, Dale W. Stahlecker, Matthew J. Stuber, Wesley C. Warren, Ronald A. Van Den BusscheCollateral damage: Anticoagulant rodenticides pose threats to California condors
Anticoagulant rodenticides (ARs) are widespread environmental contaminants that pose risks to scavenging birds because they routinely occur within their prey and can cause secondary poisoning. However, little is known about AR exposure in one of the rarest avian scavengers in the world, the California condor (Gymnogyps californianus). We assessed AR exposure in California condors and surrogate turAuthorsGarth Herring, Collin Eagles-Smith, Rachel Wolstenholme, Alacia Welch, Chris West, Barnett A. RattnerMercury exposure of tidal marsh songbirds in the northeastern United States and its association with nest survival
The biogeochemistry of tidal marsh sediments facilitates the transformation of mercury (Hg) into the biologically available form methylmercury (MeHg), resulting in elevated Hg exposures to tidal marsh wildlife. Saltmarsh and Acadian Nelson’s sparrows (Ammospiza caudacutua and A. nelsoni subvirgatus, respectively) exclusively inhabit tidal marshes, potentially experiencing elevated risk to Hg exposAuthorsKatherine J Ruskin, Garth Herring, Collin Eagles-Smith, Alyssa B. Eiklor, Chris S Elphick, Matthew A. Etterson, Chrisopher B. Field, Rebecca A. Longnecker, Adrienne I. Kovach, W Greg Shriver, James F. Walsh, Brian J. OlsenSmall mammal shooting as a conduit for lead exposure in avian scavengers
Lead (Pb) exposure is a widespread wildlife conservation threat. Although commonly associated with Pb-based ammunition from big-game hunting, small mammals (e.g., ground squirrels) shot for recreational or pest-management purposes represent a potentially important Pb vector in agricultural regions. We measured the responses of avian scavengers to pest-shooting events and examined their Pb exposureAuthorsGarth Herring, Collin Eagles-Smith, John Goodell, Jeremy A. Buck, James WillackerThe lead (Pb) lining of agriculture‐related subsidies: enhanced Golden Eagle growth rates tempered by Pb exposure
Supplementary food resources (e.g., subsidies) associated with agriculture can benefit wildlife species, increasing predictability and availability of food. Avian scavengers including raptors often utilize subsidies associated with both recreational hunting and pest shooting on agricultural lands. However, these subsidies can contain lead (Pb) fragments if they are culled with Pb‐based ammunition,AuthorsGarth Herring, Collin Eagles-Smith, Jeremy A. Buck, Alyssa E. Shiel, Chris R. Vennum, Colleen Emery, Branden L. Johnson, David Leal, Julie A. Heath, Benjamin M Dudek, Charles R. Preston, Brian WoodbridgeAnticoagulant rodenticides in Strix owls indicate widespread exposure in west coast forests
Exposure of nontarget wildlife to anticoagulant rodenticides (AR) is a global conservation concern typically centered around urban or agricultural areas. Recently, however, the illegal use of ARs in remote forests of California, USA, has exposed sensitive predators, including the federally threatened northern spotted owl (Strix occidentalis caurina). We used congeneric barred owls (S. varia) as aAuthorsDavid Wiens, Krista E. Dilione, Collin A. Eagles-Smith, Garth Herring, Damon B. Lesmeister, Mourad W. Gabriel, Greta Wengert, David C. SimonMercury and lead exposure in avian scavengers from the Pacific Northwest suggest risks to California condors: Implications for reintroduction and recovery
Mercury (Hg) and lead (Pb) are widespread contaminants that pose risks to avian scavengers. In fact, Pb exposure is the primary factor limiting population recovery in the endangered California condor (Gymnogyps californianus) and Hg can impair avian reproduction at environmentally relevant exposures. The Pacific Northwest region of the US was historically part of the condor's native range, and effAuthorsGarth Herring, Collin A. Eagles-Smith, Daniel E. VarlandCritically assessing the utility of portable lead analyzers for wildlife conservation
Lead (Pb) exposure in wildlife is a widespread management and conservation concern. Quantitative determination of Pb concentrations in wildlife tissues is the foundation for estimating exposure and risk. Development of low‐cost, portable instruments has improved access and cost‐effectiveness of determining Pb concentrations in blood samples, while also facilitating the ability for wildlife researcAuthorsGarth Herring, Collin A. Eagles-Smith, Bryan Bedrosian, Derek Craighead, Robert Domenech, Heiko W. Langner, Chris N. Parish, Adam Shreading, Alacia Welch, Rachel WolstenholmeCharacterizing Golden Eagle risk to lead and anticoagulant rodenticide exposure: A review
Contaminant exposure is among the many threats to Golden Eagle (Aquila chrysaetos) populations throughout North America, particularly lead poisoning and anticoagulant rodenticides (AR). These threats may act in concert with others (e.g., lead poisoning and trauma associated with striking objects) to exacerbate risk. Golden Eagles are skilled hunters but also exploit scavenging opportunities, makinAuthorsGarth Herring, Collin A. Eagles-Smith, Jeremy A. BuckCorrelates of immune defenses in golden eagle nestlings
An individual's investment in constitutive immune defenses depends on both intrinsic and extrinsic factors. We examined how Leucocytozoon parasite presence, body condition (scaled mass), heterophil-to-lymphocyte (H:L) ratio, sex, and age affected immune defenses in golden eagle (Aquila chrysaetos) nestlings from three regions: California, Oregon, and Idaho. We quantified hemolytic-complement activAuthorsElisabeth MacColl, Kris Vanesky, Jeremy A. Buck, Benjamin Dudek, Collin A. Eagles-Smith, Julie A. Heath, Garth Herring, Chris Vennum, Cynthia J. DownsMercury exposure may influence fluctuating asymmetry in waterbirds
Variation in avian bilateral symmetry can be an indicator of developmental instability in response to a variety of stressors, including environmental contaminants. The authors used composite measures of fluctuating asymmetry to examine the influence of mercury concentrations in 2 tissues on fluctuating asymmetry within 4 waterbird species. Fluctuating asymmetry increased with mercury concentrationAuthorsGarth Herring, Collin A. Eagles-Smith, Joshua T. AckermanNon-USGS Publications**
Lyons, J.E., Collazo, J.A., Herring, G., 2015, Testing assumptions for conservation of migratory shorebirds and coastal managed wetlands: Wetlands Ecology Management, p. online, https://doi.org/10.1007/s11273-015-9477-4.Ackerman, J.T., Herzog, M., Hartman, C.A., Herring, G., 2014, Forster’s tern chick survival in response to a managed relocation of predatory California gulls: The Journal of Wildlife Management, v. 78, no. 5, p. 818-829, https://doi.org/10.1002/jwmg.728.Hartman, C.A., Ackerman, J.T., Herring, G., Isanhart, J., Herzog, M., 2013, Marsh wrens as bioindicators of mercury in wetlands of Great Salt Lake- do blood and feathers reflect site-specific exposure risk to bird reproduction?: Environmental Science and Technology, v. 47, no. 12, p. 6597-6605, https://doi.org/10.1021/es400910x.Herring, G., Ackerman, J.T., Herzog, M.P., 2012, Mercury exposure may suppress baseline corticosterone levels in juvenile birds: Environmental Science and Technology, v. 46, p. 6339-6346.Hill, N.J., Takekawa, J.Y., Ackerman, J.T., Hobson, K.A., Herring, G., Cardona, C.J., Runstadler, J.A., Boyce, W.M., 2012, Migration strategy affects avian influenza dynamics in mallards (Anas platyrhynchos): Molecular Ecology, p. online, https://doi.org/10.1111/j.1365-294X.2012.05735.x.Herring, G., Ackerman, J.T., 2011, California gull chicks raised near colony edges have elevated stress levels: General and Comparative Endocrinology, v. 173, p. 72-77.Herring, G., Herring, H.K., Gawlik, D.E., 2015, Social Cues and Environmental Conditions Influence Foraging Flight Distances of Breeding Wood Storks (Mycteria americana): Waterbirds, v. 38, no. 1, p. 30-39, https://doi.org/10.1675/063.038.0105.Herring, G., Ackerman, J.T., Takekawa, J.Y., Eagles-Smith, C.A., Eadie, J.M., 2011, Identifying nest predators of American avocets (Recurvirostra americana) and black-necked stilts (Himantopus mexicanus) in San Francisco Bay, California: Southwestern Naturalist, v. 56, no. 1, p. 35-43.Beerens, J.M., Gawlik, D.E., Herring, G., Cook, M.I., 2011, Dynamic habitat selection by two wading bird species with divergent foraging strategies in a seasonally fluctuating wetland: Auk, v. 128, p. 651-662.Herring, G., Ackerman, J.T., Eagles-Smith, C.A., Adelsbach, T.L., Melancon, M.J., Stebbins, K.R., Hoffman, D.J., 2010, Organochlorine and PBDE concentrations in relation to cytochrome P450 activity in livers of Forster's terns (Sterna forsteri)and Caspian terns(Hydroprogne caspia),in San Francisco Bay, California: Sm, v. 58, p. 863-873.Herring, G., Ackerman, J.T., Eagles-Smith, C.A., Takekawa, J.Y., 2010, Sexing California gulls using morphometrics and discriminant function analysis: Waterbirds, v. 33, no. 1, p. 79-85.Herring, G., Collazo, J.A., 2009, Site characteristics and prey abundance at foraging sites used by lesser scaup (Aythya affinis)wintering in Florida: Southeastern Naturalist, v. 8, p. 363-374.Herring, G., Gawlik, D.E., 2012, Differential physiological responses to prey availability by the great egret and white ibis: Journal of Wildlife Management, p. online, https://doi.org/10.1002/jwmg.445.Dorn, N.J., Cook, M.I., Herring, G., Boyle, R.A., Nelson, J., Gawlik, D.E., 2011, Aquatic prey switching and urban foraging by the white ibis Eudocimus albusare determined by wetland hydrological conditions: Ibis, v. 153, p. 323-335.Herring, G., Cook, M.I., Gawlik, D.E., Call, E.M., 2011, Food availability is expressed through physiological stress indicators in nestling white ibis- a food supplementation experiment: Functional Ecology, v. 25, p. 682-690.Herring, G., Gawlik, D.E., 2010, Avian radio-transmitter harness wear and failure: Southeastern Naturalist, v. 9, p. 595-604.Herring, G., Ackerman, J.T., Eagles-Smith, C.A., 2010, Embryo malposition as a potential mechanism for mercury-induced hatching failure in bird eggs: Environmental Toxicology and Chemistry, v. 29, no. 8, p. 1788-1794.Herring, G., Gawlik, D.E., Cook, M.I., Beerens, J.M., 2010, Sensitivity of nesting great egrets (Ardea alba)and white ibises(Eudocimus albus)to reduced prey availability: Auk, v. 127, p. 660-670.Herring, G., Gawlik, D.E., Rumbold, D.G., 2009, Feather mercury concentrations and physiological condition of great egret and white ibis nestlings in the Florida Everglades: Science of the Total Environment, v. 407, p. 2641-2649.Herring, G., Gawlik, D.E., 2009, Stability of avian fecal corticosterone metabolite levels in frozen avian feces: Journal of Wildlife Management, v. 73, p. 1010-1013.Dorn, N.J., Herring, G., Gawlik, D.E., 2008, Estimation of crayfish abundance and size-structure in diets of white ibis chicks: Waterbirds, v. 31, p. 417-423.Herring, G., Gawlik, D.E., Beerens, J.M., 2008, Evaluating two new methods for capturing large wetland birds: Journal of Field Ornithology, v. 79, p. 102-110.Herring, G., Gawlik, D.E., 2008, Potential for successful population establishment of the nonindigenous sacred ibis in the Florida Everglades: Biological Invasions, v. 10, p. 969-976.Herring, G., Gawlik, D.E., Beerens, J.M., 2008, Sex determination for the great egret and white ibis: Waterbirds, v. 31, p. 298-303.Marx, D.E., Hejl, S.J., Herring, G., 2008, Wintering grassland bird habitat selection following summer prescribed fire in a Texas Gulf Coast tallgrass prairie: Fire Ecology Special Issue, v. 4, no. 2, p. 46-62.Herring, G., Gawlik, D.E., 2007, The role of stress proteins in the study of allostatic overload in birds- Use and applicability to current studies in avian ecology: The Scientific World Journal, v. 7, p. 1596-1602.Herring, G., Collazo, J.A., 2006, Lesser scaup winter foraging and nutrient reserve acquisition in east-central Florida: Journal of Wildlife Management, v. 70, p. 1682-1689.Rivera-Milan, F.F., Collazo, J.A., Stahala, C., Moore, W.J., Davis, A., Herring, G., Steinkamp, M., Pagliaro, R., Thompson, J.L., Bracey, W., 2005, Estimation of density and population size and recommendations for monitoring trends of Bahama parrots on Great Abaco and Great Inagua: Wildlife Society Bulletin, v. 33, p. 823-834.Herring, G., Collazo, J.A., 2005, Habitat use, movements, and home range of wintering lesser scaup in Florida: Waterbirds, v. 28, p. 71-78.Herring, G., Collazo, J.A., 2004, Winter survival of lesser scaup in east-central Florida: Journal of Wildlife Management, v. 68, p. 1082-1087.Knapton, R.W., Petrie, S.A., Herring, G., 2000, Human disturbance of diving ducks on Long Point Bay, Lake Erie: Wildlife Society Bulletin, v. 28, p. 923-930.**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.
- 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