Dr. Susan De La Cruz is a Wildlife Biologist with the U.S. Geological Survey's Western Ecological Research Center.
She has over 20 years of wildlife research experience in San Francisco Bay Delta and along the Pacific and Central Flyways and as the senior researcher at the San Francisco Bay Estuary Field Station, she oversees and directs research activities. With Federal, State, University, non-profit, and local partners, she is actively involved in designing, funding, implementing and publishing research on foraging and migration ecology, winter habitat use, survival and contaminant effects in nearshore avian species. Her Ph.D. research focused on how changes in benthic prey resources in the estuary influence winter body condition, subsequent spring migration and cross-seasonal reproduction in surf scoters (Melanitta perspicillata), a declining sea duck species that winters in along the Pacific coast. Other current research includes modeling effects of sea-level rise and geomorphic change on avian foraging ecology and carrying capacity, evaluating the effects of water traffic on avian habitat use and behavior, measuring post-oil spill survival and behavior, determining the value of natural and restored intertidal and subtidal habitats for waterbirds and tidal marsh endemics, assessing impacts of dredge operations on benthic communities, and assessing the effectiveness of sediment augmentation (sediment subsidies) on tidal marsh resiliency.
HIGHLIGHTED PUBLICATIONS
Harris, M.C., Pearce, J.M., Prosser, D.J., White, C.L., Miles, A.K., Sleeman, J.M., Brand, C.J., Cronin, J.P., De La Cruz, S., Densmore, C.L., Doyle, T.W., Dusek, R.J., Fleskes, J.P., Flint, P.L., Guala, G.F., Hall, J.S., Hubbard, L.E., Hunt, R.J., Ip, H.S., Katz, R.A., Laurent, K.W., Miller, M.P., Munn, M.D., Ramey, A.M., Richards, K.D., Russell, R.E., Stokdyk, J.P., Takekawa, J.Y., and Walsh, D.P. 2016. U.S. Geological Survey science strategy for highly pathogenic avian influenza in wildlife and the environment (2016–2020): U.S. Geological Survey Open-File Report 2016–1121, 38 p., http://dx.doi.org/10.3133/ofr20161121.
Mills, K.L., J.K. Gaydos, C.G. Fiorello, E.R. Whitmer, S.E.W. De La Cruz, D.M. Mulcahy, L.I. Vilchis, and M.H. Ziccardi. 2016. Post-release survival and movement of Western Grebes (Aechmophorus occidentalis) implanted with intracoelomic satellite transmitters. Waterbirds 39(2):175-186. http://dx.do
Education and Certifications
University of California, Davis: Ph.D., Ecology, Ecotoxicology Emphasis, December 2010
Dissertation title: Habitat, Diet, and Contaminant Relationships of Surf Scoters Wintering in San Francisco
Texas A&M University: M.S., Wildlife and Fisheries Sciences, December 1998
Thesis title: Screening for Endocrine Disrupting Effects of Xenobiotics in Wildlife Using Oxbow Lakes and Settling
University of California, Davis: B.S., Biological Sciences, December 1992
Science and Products
Avian Influenza Prevalence Correlated to Mercury Concentrations in Wild Waterfowl
New Technologies for Wildlife Tracking
Mercury Accumulation in Waterbirds (Black Rails) Related to Sediment Chemistry in San Francisco Bay Wetlands
Selenium Hazard in the Salton Sea Environment, Summary of Current Knowledge to Inform Future Science
Assessing the Benefits and Vulnerability of Current and Future Potential Ecosystem Services of the Nisqually River Delta and other Puget Sound Estuaries
Suisun Marsh Waterfowl and Wildlife Studies
Avian Ecology and Multi-Species Habitat Use in Pacific Coast Estuaries
Wetland Restoration in the San Francisco Bay Delta and Pacific Northwest
Pacific Coast Fisheries GIS Resource Database
San Francisco Bay Benthic Macroinvertebrate Atlas
San Francisco Bay Estuary Field Station
Food Web and Invertebrate Ecology Studies in Pacific Coast Estuaries
Data describing infection status and movement ecology of North American waterfowl
Data measuring avian influenza infection, mercury concentration, and body condition in wild waterfowl
Aquatic Prey Resources in Response to Estuary Restoration in Willapa Bay, Washington (2014-2015)
Biological Tissue Data Used to Evaluate Selenium Hazards in the Salton Sea Ecosystem (1984-2020)
Sediment biogeochemistry and subsequent mercury biomagnification in wetland food webs of the San Francisco Bay, CA
Western sandpiper diet composition in south San Francisco Bay, CA
Tidal marsh biomass field plot and remote sensing datasets for six regions in the conterminous United States (ver. 2.0, June 2020)
Temporal Viral Viability Data from Avian Influenza A Viruses Maintained in North American Wetlands Under Experimental and Environmental Conditions
Small mammal surveys from northern San Francisco Bay: 1998-2014
Demographics and gross pathology of scoters and scaups killed by the Cosco Busan oil spill in California
Waterfowl recently infected with low pathogenic avian influenza exhibit reduced local movement and delayed migration
Avian influenza antibody prevalence increases with mercury contamination in wild waterfowl
Spatiotemporal changes in influenza A virus prevalence among wild waterfowl inhabiting the continental United States throughout the annual cycle
Reference values and comparison of blood chemistry and plasma protein values between gold standard analyzers and four point-of-care devices in free-ranging canvasbacks (Aythya valisineria)
A climate-mediated shift in the estuarine habitat mosaic limits prey availability and reduces nursery quality for juvenile salmon
Pathways for avian influenza virus spread: GPS reveals wild waterfowl in commercial livestock facilities and connectivity with the natural wetland landscape
Host correlates of avian influenza virus infection in wild waterfowl of the Sacramento Valley, California
Small shorebirds feast on green slime to fuel their long migration
Climate change vulnerability assessment for the California coastal national monument—Trinidad and Point Arena-Stornetta units
Effects of season, location, species, and sex on hematologic and plasma biochemical values and body mass in free-ranging Grebes (Aechmophorus species)
Age‐ and sex‐related dietary specialization facilitate seasonal resource partitioning in a migratory shorebird
Science and Products
- Science
Filter Total Items: 13
Avian Influenza Prevalence Correlated to Mercury Concentrations in Wild Waterfowl
Low pathogenic avian influenza infections were directly correlated with blood mercury concentrations in wild waterfowl, indicating that mercury exposure may be related to pathogen susceptibility. Further study is needed to determine if and how mercury and other environmental contaminant exposures may affect disease susceptibility in wildlife.New Technologies for Wildlife Tracking
Next generation of wildlife tracking using light-weight, 3D printed, waterproof tags.Mercury Accumulation in Waterbirds (Black Rails) Related to Sediment Chemistry in San Francisco Bay Wetlands
The U.S. Geological Survey (USGS) assessed the effect of sediment chemistry, food web structure, and diet on mercury bioaccumulation in black rails in the San Francisco Bay watershed. Differences in mercury accumulation in the birds were related to differences in sediment chemistry in the wetlands.Selenium Hazard in the Salton Sea Environment, Summary of Current Knowledge to Inform Future Science
The effect of selenium (Se) toxicity on wildlife has been known for more than 50 years. The threat of Se contamination gained greater attention from federal agencies in the 1980s due to the observation of embryo deformity and mortality in birds at a National Wildlife Refuge in California. Harmful effects from Se were determined to be connected to irrigation drainage water. As a result, an effort...Assessing the Benefits and Vulnerability of Current and Future Potential Ecosystem Services of the Nisqually River Delta and other Puget Sound Estuaries
The Nisqually River Delta represents the largest wetland restoration in the Pacific Northwest. The restoration resulted in a 50% increase in potential salt marsh habitat. The Delta supports threatened salmon fisheries, large populations of migratory birds, and provides unique opportunities for recreation. The Delta also provides multiple ecosystem services, which are the benefits that wildlife orSuisun Marsh Waterfowl and Wildlife Studies
Suisun Marsh provides critical habitat for wintering and breeding waterbirds in California. USGS WERC collaborates with the California Department of Water Resources to examine trends in bird declines and to assess the habitat factors driving long-term survival of waterfowl, rails, and other birds in this important area.Avian Ecology and Multi-Species Habitat Use in Pacific Coast Estuaries
Waterbirds such as shorebirds, waders, and ducks depend on healthy and productive estuaries to “fuel up” for long distance migrations along the Pacific Flyway. Estuarine ecosystems include a mosaic of managed, natural, and restoring wetlands, and provide critical stop-over and wintering areas for federally protected migratory bird species. USGS WERC’s Dr. Susan De La Cruz works with federal, state...Wetland Restoration in the San Francisco Bay Delta and Pacific Northwest
Estuaries and healthy coastal habitats are among the most productive ecosystems on Earth. They provide a variety of benefits, including habitat and food for fish and wildlife, flood and erosion protection, improved water quality, increased carbon sequestration, as well as beautiful scenery and opportunities for recreation. Along the U.S. Pacific Coast, both the San Francisco Bay estuary and the...Pacific Coast Fisheries GIS Resource Database
Pacific Coast fisheries information is currently available only from wildlife agencies in disparate databases. To maximize the value of these data, the Bureau of Ocean Energy Management, Regulation, and Enforcement and U. S. Geological Survey have combined data from several of these sources into a single, comprehensive database. This gives resource managers a tool to easily extract species or...San Francisco Bay Benthic Macroinvertebrate Atlas
Information on benthic macroinvertebrate populations is currently available from numerous agencies in disparate databases. To maximize the value of these data, San Francisco State University and the U. S. Geological Survey have combined data from several of these sources into a single comprehensive database. To request this database, please contact Dr. Susan De La Cruz (sdelacruz@usgs.gov)San Francisco Bay Estuary Field Station
The San Francisco Bay Field Station is the center of studies on recovering tidal wetland ecosystems and ongoing efforts to balance the restoration of local marshes and the needs of seabirds. Click on the "Science" tab for a comprehensive summary of this station and its research.Food Web and Invertebrate Ecology Studies in Pacific Coast Estuaries
Invertebrate communities provide food for several economically and ecologically important fish and waterbird species in coastal estuaries. Scientists at the WERC San Francisco Bay Estuary Field Station specialize in studying foraging ecology of waterbirds and fishes, general food web dynamics across estuaries, and the effects of habitat restoration and other factors on waterbird prey availability. - Data
Data describing infection status and movement ecology of North American waterfowl
These data, which support a USGS authored manuscript, describe how active and previous previous infection with avian influenza impacts the movement ecology of several wild waterfowl species that overwinter in California. Results varied by species and demonstrate that the relationships between avian influenza infection and wild bird movements are context- and species-dependent.Data measuring avian influenza infection, mercury concentration, and body condition in wild waterfowl
These data represent mercury contamination, influenza infection, and body condition in 11 species of dabbling and diving ducks in the Pacific Flyway. These data support a USGS lead scientific publication.Aquatic Prey Resources in Response to Estuary Restoration in Willapa Bay, Washington (2014-2015)
The ongoing restoration of more than 200 hectares of estuarine habitat at Willapa National Wildlife Refuge, southwestern Washington, is expected to benefit a variety of species, including salmonids that use estuarine and tidal marshes as rearing and feeding areas as well as migratory waterbirds. During March through June 2014 and 2015, this study was initiated to assess aquatic prey resources. WeBiological Tissue Data Used to Evaluate Selenium Hazards in the Salton Sea Ecosystem (1984-2020)
In response to the rapidly evolving conditions at the Salton Sea with the emergence of both newly formed wetland habitat and increasing hazards to wildlife, the U.S. Bureau of Reclamation and U.S. Geological Survey have funded a re-evaluation of data gaps regarding selenium concentrations in biota the region. As part of this work, selenium concentrations in biological tissue samples were compiledSediment biogeochemistry and subsequent mercury biomagnification in wetland food webs of the San Francisco Bay, CA
Methylmercury (MeHg) is a globally pervasive contaminant that biomagnifies in food webs and can reach toxic concentrations in consumers at higher trophic levels, including wildlife and humans. The production of MeHg, and its subsequent entry and biomagnification in food webs, is governed by a complex suite of biogeochemical, physical, and ecological processes, resulting in variation in the distribWestern sandpiper diet composition in south San Francisco Bay, CA
Diet composition can be influenced by age- and sex-related factors including an individual's morphology, social status, and acquired skills; however, specialization may only be necessary when competition is intensified by high population densities or increased energetic demands. The western sandpiper is a small (22-35 grams) migratory shorebird that exhibits female-biased sexual size dimorphism wiTidal marsh biomass field plot and remote sensing datasets for six regions in the conterminous United States (ver. 2.0, June 2020)
Remote sensing based maps of tidal marshes, both of their extents and carbon stocks, have the potential to play a key role in conducting greenhouse gas inventories and implementing climate mitigation policies. Our objective was to generate a single remote sensing model of tidal marsh aboveground biomass and carbon that represents nationally diverse tidal marshes within the conterminous United StatTemporal Viral Viability Data from Avian Influenza A Viruses Maintained in North American Wetlands Under Experimental and Environmental Conditions
Data sets containing: (1) sample collection and influenza A virus (IAV) screening information for wild ducks, (2) water temperature data for six North American wetlands, (3) water quality measurement from those wetlands, (4) laboratory-based study of viral viability using Minnesota wetland water, (5) naive mallards challenged experimentally with IAVs identified from the field experiment, and (6) gSmall mammal surveys from northern San Francisco Bay: 1998-2014
This datasets summarizes small mammal trapping efforts that USGS San Francisco Bay Estuary Field Station has led, co-led, or supervised, to detect and monitor the endangered salt marsh harvest mouse (Reithrodontomys raviventris) in the northern reaches of San Francisco Bay from 1998-2014. As the salt marsh harvest mouse is listed as endangered under the Endangered Species Act, sensitive location - Publications
Filter Total Items: 47
Demographics and gross pathology of scoters and scaups killed by the Cosco Busan oil spill in California
Unusual wildlife mortality events provide a unique opportunity to collect information on demographics, disease, and body condition in affected wildlife, which may be useful for informing oil spill damage assessments and future spill responses. In November 2007, the Cosco Busan Oil Spill occurred in San Francisco Bay, California, a globally important wintering area for waterfowl. The spill resultedAuthorsJessie Beck, Ryan D. Carle, HannahRose M. Nevins, Susan E. W. De La Cruz, Erica Donnelly-GreenanWaterfowl recently infected with low pathogenic avian influenza exhibit reduced local movement and delayed migration
Understanding relationships between infection and wildlife movement patterns is important for predicting pathogen spread, especially for multispecies pathogens and those that can spread to humans and domestic animals, such as avian influenza viruses (AIVs). Although infection with low pathogenic AIVs is generally considered asymptomatic in wild birds, prior work has shown that influenza-infected bAuthorsClaire S. Teitelbaum, Michael L. Casazza, Fiona McDuie, Susan E. W. De La Cruz, Cory T. Overton, Laurie Anne Hall, Elliott Matchett, Josh T. Ackerman, Jeffery D. Sullivan, Andrew M. Ramey, Diann ProsserAvian influenza antibody prevalence increases with mercury contamination in wild waterfowl
Environmental contamination is widespread and can negatively impact wildlife health. Some contaminants, including heavy metals, have immunosuppressive effects, but prior studies have rarely measured contamination and disease simultaneously, which limits our understanding of how contaminants and pathogens interact to influence wildlife health. Here, we measured mercury concentrations, influenza infAuthorsClaire Stewart Teitelbaum, Josh T. Ackerman, Mason A. Hill, Jaqueline M. Satter, Michael L. Casazza, Susan E. W. De La Cruz, Walter M. Boyce, Evan James Buck, John M. Eadie, Mark P. Herzog, Elliott Matchett, Cory T. Overton, Sarah H. Peterson, Magdalena Plancarte, Andrew M. Ramey, Jeffery D. Sullivan, Diann ProsserSpatiotemporal changes in influenza A virus prevalence among wild waterfowl inhabiting the continental United States throughout the annual cycle
Avian influenza viruses can pose serious risks to agricultural production, human health, and wildlife. An understanding of viruses in wild reservoir species across time and space is important to informing surveillance programs, risk models, and potential population impacts for vulnerable species. Although it is recognized that influenza A virus prevalence peaks in reservoir waterfowl in late summeAuthorsCody M. Kent, Andrew M. Ramey, Josh T. Ackerman, Justin Bahl, Sarah N. Bevins, Andrew S. Bowman, Walter Boyce, Carol Cardona, Michael L. Casazza, Troy D. Cline, Susan E. W. De La Cruz, Jeffrey S. Hall, Nichola J. Hill, Hon S. Ip, Scott Krauss, Jennifer M. Mullinax, Jacqueline M. Nolting, Magdalena Plancarte, Rebecca L. Poulson, Jonathan A. Runstadler, Richard D. Slemons, David E. Stallknecht, Jeffery D. Sullivan, John Y. Takekawa, Richard J. Webby, Robert G. Webster, Diann J. ProsserReference values and comparison of blood chemistry and plasma protein values between gold standard analyzers and four point-of-care devices in free-ranging canvasbacks (Aythya valisineria)
Accurate, timely, and cost-effective blood chemistry analysis is an essential tool for directing emergency treatment, monitoring the health status of captive and free-ranging individuals and flocks, and improving the efficacy of conservation actions. Blood samples were obtained from 52 canvasbacks (Aythya valisineria) that were captured on San Francisco Bay, California, during December 2017 as parAuthorsNancy L. Anderson, Susan E. W. De La Cruz, Maris Brenn-White, Greg Frankfurter, Michael H. Ziccardi, Beatriz Martínez-LópezA climate-mediated shift in the estuarine habitat mosaic limits prey availability and reduces nursery quality for juvenile salmon
The estuarine habitat mosaic supports the reproduction, growth, and survival of resident and migratory fish species by providing a diverse portfolio of unique habitats with varying physical and biological features. Global climate change is expected to result in increasing temperatures, rising sea levels, and changes in riverine hydrology, which will have profound effects on the extent and compositAuthorsMelanie J. Davis, Isa Woo, Christopher S. Ellings, Sayre Hodgson, David Beauchamp, Glynnis Nakai, Susan E. W. De La CruzPathways for avian influenza virus spread: GPS reveals wild waterfowl in commercial livestock facilities and connectivity with the natural wetland landscape
Zoonotic diseases are of considerable concern to the human population and viruses such as avian influenza (AIV) threaten food security, wildlife conservation and human health. Wild waterfowl and the natural wetlands they use are known AIV reservoirs, with birds capable of virus transmission to domestic poultry populations. While infection risk models have linked migration routes and AIV outbreaks,AuthorsFiona McDuie, Elliott Matchett, Diann Prosser, John Y. Takekawa, Maurice E. Pitesky, Austen Lorenz, Madeline M McCuen, Cory T. Overton, Josh T. Ackerman, Susan E. W. De La Cruz, Michael L. CasazzaHost correlates of avian influenza virus infection in wild waterfowl of the Sacramento Valley, California
Avian influenza viruses (AIVs) are distributed globally in members of the family Anatidae (waterfowl), and significant disease may occur when these viruses infect commercial poultry or humans. Early detection of AIV through surveillance of wild waterfowl is one measure to prevent future disease outbreaks. Surveillance efforts that are designed to account for host and environmental determinants ofAuthorsElizabeth A. Bianchini, Raymond J. Bogiatto, Robin A. Donatello, Michael L. Casazza, Josh T. Ackerman, Susan E. W. De La Cruz, Troy D. ClineSmall shorebirds feast on green slime to fuel their long migration
Shorebirds wade in shallow waters along shorelines searching for food. More than a million shorebirds visit the San Francisco Estuary each year during their migration to feast on the insects, worms, clams, and crabs that live on or under the surface of the sand or mud. The abundant food in the Estuary provides shorebirds with the energy they need to migrate thousands of kilometers, between their bAuthorsLaurie Anne Hall, Susan E. W. De La Cruz, Isa Woo, Tomohiro Kuwae, David Mcgovern Nelson, John Y. TakekawaClimate change vulnerability assessment for the California coastal national monument—Trinidad and Point Arena-Stornetta units
Executive SummaryThe California Coastal National Monument protects islets, reefs, and rock outcropping habitats in six onshore units, including the Trinidad and Point Arena-Stornetta Units.The California Coastal National Monument provides crucial habitat for resident and migratory species of seabirds, marine mammals, and invertebrates, which includes several federally listed threatened and endangeAuthorsKaren M. Thorne, Chase M. Freeman, Kevin J. Buffington, Susan E.W. De La CruzEffects of season, location, species, and sex on hematologic and plasma biochemical values and body mass in free-ranging Grebes (Aechmophorus species)
The effects of season, location, species, and sex on body weight and a comprehensive array of blood chemistry and hematology analytes were compared for free-ranging western (Aechmophorus occidentalis) and Clark's (Aechmophorus clarkii) grebes. Birds (n = 56) were collected from Puget Sound, WA, and Monterey Bay and San Francisco Bay, CA, from February 2007 to March 2011. The data supported generalAuthorsNancy L Anderson, Susan E. W. De La Cruz, Joseph K Gaydos, Michael H. Ziccardi, Danielle J HarveyAge‐ and sex‐related dietary specialization facilitate seasonal resource partitioning in a migratory shorebird
Dietary specialization is common in animals and has important implications for individual fitness, inter‐ and intraspecific competition, and the adaptive potential of a species. Diet composition can be influenced by age‐ and sex‐related factors including an individual's morphology, social status, and acquired skills; however, specialization may only be necessary when competition is intensified byAuthorsLaurie Anne Hall, Susan E. W. De La Cruz, Isa Woo, Tomohiro Kuwae, John Y. Takekawa - News