Dr. Ackerman is a Principal Investigator with USGS and an Associate in the Department of Wildlife, Fish, and Conservation Biology at the University of California-Davis.
His research expertise is in wildlife ecology and ecotoxicology, and his research program focuses on bird ecology, wetland management and restoration, contaminant bioaccumulation in fish and wildlife, and effects of contaminants on animal health and populations.
Education
- Ph.D. 2002, Ecology, University of California-Davis
- B.S. 1997 (Magna Cum Laude), Wildlife, Fish, and Conservation Biology, University of California-Davis
Professional Experience
- Research Wildlife Biologist, U.S. Geological Survey, Western Ecological Research Center, Dixon Field Station, California (2006-present)
- Wildlife Biologist, U.S. Geological Survey, Western Ecological Research Center, San Francisco Bay Estuary Field Station, Vallejo, California (2004-2006)
- Post-doctoral Researcher, John Muir Institute of the Environment, University of California-Davis (2003-2004)
- Post-doctoral Researcher, Dept. of Wildlife, Fish, and Conservation Biology, University of California-Davis (2002-2003)
- Teaching Assistant, Ecology and Management of Waterfowl and Game Birds (Spring 2002) and Field Methods in Wildlife, Fish, and Conservation Biology (Summer 2001), Dept. of Wildlife, Fish, and Conservation Biology, University of California-Davis
- Waterfowl Researcher (1999-2000), Crew Leader (Spring 1998, 1999, 2000), and Technician (Spring 1997), California Waterfowl Association, Sacramento, California
- Doctoral Research, Dept. of Wildlife, Fish, and Conservation Biology, University of California-Davis (1997-2002)
- Biological Technician (Summer 1995) and Biological Aid (Summer 1994), U.S. Forest Service, Tahoe National Forest, Nevada City, California
Selected Publications
2020 Ackerman, JT, MP Herzog, DC Evers, DA Cristol, KP Kenow, GH Heinz, RA Lavoie, RL Brasso, ML Mallory, JF Provencher, BM Braune, A Matz, JA Schmutz, CA Eagles-Smith, LJ Savoy, MW Meyer, and CA Hartman. Synthesis of maternal transfer of mercury in birds: implications for altered toxicity risk. Environmental Science and Technology 54:2878-2891.
2016 Ackerman, JT, CA Eagles-Smith, MP Herzog, CA Hartman, SH Peterson, DC Evers, AK Jackson, JE Elliott, SS Vander Pol, and CE Bryan. Avian mercury exposure and toxicological risk across western North America: a synthesis. Science of the Total Environment 568:749-769.
2014 Ackerman, JT, MP Herzog, GS Yarris, ML Casazza, E Burns, and JM Eadie. Chapter 5: Waterfowl ecology and management in Suisun Marsh: Ecological History and Possible Futures. University of California Press: Berkeley, California.
Science and Products
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
Migration stopover ecology of Cinnamon Teal in western North America
Wetland availability and salinity concentrations for breeding waterfowl in Suisun Marsh, California
Breeding waterbird populations have declined in south San Francisco Bay: An assessment over two decades
Informing wetland management with waterfowl movement and sanctuary use responses to human-induced disturbance
Nocturnal incubation recess and flushing behavior by duck hens
Demethylation of methylmercury in bird, fish, and earthworm
Foraging in marine habitats increases mercury concentrations in a generalist seabird
Isotope fractionation from In Vivo methylmercury detoxification in waterbirds
Egg morphometrics and egg shape coefficients for White-faced Ibis (Plegadis chihi)
Interrupted incubation: How dabbling ducks respond when flushed from the nest
Wetland Management Technique Designed to Reduce Mercury in Water and Fish Tested During a Short-Term Field Study
Science to Help Understand Exposure and Toxicological Effects of Environmental Mercury to Representative Birds
Ecologically-Driven Exposure Pathways Science Team
Suisun Marsh Waterfowl and Wildlife Studies
Scientists Identify Processes that Affect Fish Mercury Concentrations in Estuarine Wetlands
New Method Can Measure Naturally Occurring Element Exposure in Hummingbirds Without Harm
Waterbird Breeding Ecology and Management
Mercury Bioaccumulation in Wetlands
Breeding and Wintering Ecology of Waterfowl
Contaminants in Waterbirds and Effects on Avian Reproduction
Efficacy of Eggshell Analyses as a Nonlethal Method to Estimate Mercury Exposure in Bird Embryos
Dixon Field Station
Nocturnal Incubation Recess and Flushing Behavior by Duck Hens Nesting in Grizzly Island Wildlife Area 2015-2018
Migration stopover ecology of cinnamon teal in western North America
Egg Morphometric Data Obtained for White-faced Ibis Nesting in Bear River Migratory Bird Refuge, Great Salt Lake, Utah (2010-2012)
How Mallard and Gadwall Hens Nesting in Grizzly Island Wildlife Area Respond when Flushed (2015 - 2018)
Breeding Waterbird Populations in South San Francisco Bay 2005-2019
Mercury Concentrations in Western Gulls along the West Coast, USA, 2015-2017
Hair and blood total mercury concentrations in raccoons and striped skunks from Suisun Marsh 2016 to 2019
Avian Eggshell Thickness for 12 Species in the Western U.S. from 2014 to 2018
Mercury Bioaccumulation in US National Parks Using Dragonfly Larvae as Biosentinels, 2009-2018
Nest data for white-faced Ibis in Bear River Migratory Bird Refuge, Great Salt Lake, Utah in summer 2012
Mercury and selenium concentrations in bird eggs at Great Salt Lake, Utah
Temporal Viral Viability Data from Avian Influenza A Viruses Maintained in North American Wetlands Under Experimental and Environmental Conditions
Re-establishing Waterbird Breeding Colonies in San Francisco Bay
This U.S. Geological Survey (USGS), Western Ecological Research Center (WERC) story map details how partners are using science and management to maintain and establish new bird nesting colonies in support of the South Bay Salt Pond Restoration Project. Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government.
Science and Products
- Publications
Filter Total Items: 176
Pathways 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,Host 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 ofMigration stopover ecology of Cinnamon Teal in western North America
Identifying migration routes and fall stopover sites of Cinnamon Teal (Spatula cyanoptera septentrionalium) can provide a spatial guide to management and conservation efforts, and address vulnerabilities in wetland networks that support migratory waterbirds. Using high spatiotemporal resolution GPS-GSM transmitters, we analyzed 61 fall migration tracks across western North America during our threeWetland availability and salinity concentrations for breeding waterfowl in Suisun Marsh, California
Availability of wetlands with low salinities during the breeding season can influence waterfowl reproductive success and population recruitment. Salinities as low as 2 ppt (3.6 mScm–1) can impair duckling growth and influence behavior, with mortality occurring above 9 ppt (14.8 mScm–1). We used satellite imagery to quantify the amount of available water, and sampled surface water salinity at GrizzBreeding waterbird populations have declined in south San Francisco Bay: An assessment over two decades
In south San Francisco Bay, former salt ponds now managed as wildlife habitat support large populations of breeding waterbirds. In 2006, the South Bay Salt Pond Restoration Project began the process of converting 50% to 90% of these managed pond habitats into tidal marsh. We compared American Avocet (Recurvirostra americana) and Black-necked Stilt (Himantopus mexicanus) abundance in south San FranInforming wetland management with waterfowl movement and sanctuary use responses to human-induced disturbance
Long-term environmental management to prevent waterfowl population declines is informed by ecology, movement behavior and habitat use patterns. Extrinsic factors, such as human-induced disturbance, can cause behavioral changes which may influence movement and resource needs, driving variation that affects management efficacy. To better understand the relationship between human-based disturbance anNocturnal incubation recess and flushing behavior by duck hens
Incubating birds must balance the needs of their developing embryos with their own physiological needs, and many birds accomplish this by taking periodic breaks from incubation. Mallard (Anas platyrhynchos) and gadwall (Mareca strepera) hens typically take incubation recesses in the early morning and late afternoon, but recesses can also take place at night. We examined nocturnal incubation recessDemethylation of methylmercury in bird, fish, and earthworm
Toxicity of methylmercury (MeHg) to wildlife and humans results from its binding to cysteine residues of proteins, forming MeHg-cysteinate (MeHgCys) complexes that hinder biological functions. MeHgCys complexes can be detoxified in vivo, yet how this occurs is unknown. We report that MeHgCys complexes are transformed into selenocysteinate (Hg(Sec)4) complexes in multiple animals from two phyla (aForaging in marine habitats increases mercury concentrations in a generalist seabird
Methylmercury concentrations vary widely across geographic space and among habitat types, with marine and aquatic-feeding organisms typically exhibiting higher mercury concentrations than terrestrial-feeding organisms. However, there are few model organisms to directly compare mercury concentrations as a result of foraging in marine, estuarine, or terrestrial food webs. The ecological impacts of dIsotope fractionation from In Vivo methylmercury detoxification in waterbirds
The robust application of stable mercury (Hg) isotopes for mercury source apportionment and risk assessment necessitates the understanding of mass-dependent fractionation (MDF) due to internal transformations within organisms. Here, we used high energy-resolution XANES spectroscopy and isotope ratios of total mercury (δ202THg) and methylmercury (δ202MeHg) to elucidate the chemical speciation of HgEgg morphometrics and egg shape coefficients for White-faced Ibis (Plegadis chihi)
Egg size is a useful metric for maternal investment, offspring quality, and contaminant studies. Yet these values and the egg shape coefficients required to estimate egg size are not available for many species, including White-faced-Ibis (Plegadis chihi). We provide egg morphometrics derived from 319 White-faced Ibis eggs sampled at Bear River Migratory Bird Refuge, Great Salt Lake, Utah, from 201Interrupted incubation: How dabbling ducks respond when flushed from the nest
Nesting birds must provide a thermal environment sufficient for egg development while also meeting self‐maintenance needs. Many birds, particularly those with uniparental incubation, achieve this balance through periodic incubation recesses, during which foraging and other self‐maintenance activities can occur. However, incubating birds may experience disturbances such as predator or human activit - Science
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Wetland Management Technique Designed to Reduce Mercury in Water and Fish Tested During a Short-Term Field Study
Results from a 3-year study indicate there was support for the use of open- and deep-water treatment pools at the downstream end of seasonal wetlands to reduce methylmercury concentrations in water exported from the wetlands, but the treatment had no measurable effect on wetland fish. Questions remain about the long-term potential for mercury removal using this wetland management strategy.Science to Help Understand Exposure and Toxicological Effects of Environmental Mercury to Representative Birds
Exposure and toxicity of environmental mercury to birds can be enhanced or lessened due to the available sources and forms of mercury and other species dependent factors such as life stage, migratory patterns, foraging and nesting behaviors, transfer of mercury from mothers to eggs, and sex. For example, mercury exposure can lead to sublethal toxicological effects that can influence parental...Ecologically-Driven Exposure Pathways Science Team
The Ecologically-Driven Exposure pathways team identifies internal and external pathways and processes that can alter exposure and toxicity of contaminants and pathogens to wildlife the environment. That information is used to distinguish actual health risks to fish and wildlife. If actual risks are identified this project will inform how to economically and effectively minimize risk by providing...Suisun 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.Scientists Identify Processes that Affect Fish Mercury Concentrations in Estuarine Wetlands
In a study designed to help resource managers when considering mercury exposure risk, scientists determined that sulfur cycling—a process closely related to mercury methylation rates—and ecological conditions that influence exposure are important factors affecting fish mercury concentrations in estuarine wetlands.New Method Can Measure Naturally Occurring Element Exposure in Hummingbirds Without Harm
Seventeen naturally occurring trace elements, including those associated with adverse health impacts when birds are exposed to toxic levels (iron, lead, mercury, selenium, zinc, cadmium, and arsenic) were measured in small birds without harm. The nonlethal method was developed for hummingbirds, with Anna's hummingbirds (Calypte anna) as a test species and can be more broadly applied to other...Waterbird Breeding Ecology and Management
The San Francisco Bay is designated as a site of hemispheric importance to shorebirds and annually supports over one million waterbirds. Within the USGS WERC waterbird breeding ecology program, Dr. Josh Ackerman and partners are studying habitat selection, movements, and factors influencing waterbird nest success and chick growth and survival.Mercury Bioaccumulation in Wetlands
Wetlands provide numerous ecosystem services, but also can be sources of methylmercury production and export. Click the next tab to learn how WERC's Dr. Josh Ackerman is evaluating the ecological factors that drive contaminant bioaccumulation in wetland-dependent fish and wildlife.Breeding and Wintering Ecology of Waterfowl
Western U.S. wetlands provide critical habitat for wintering and breeding waterfowl in California. WERC's Dr. Josh Ackerman is working toward collecting data to understand factors influencing duck nest success, to improve and restore breeding habitat for resident duck populations in California, and understand composition of predator communities. To learn more about how USGS WERC is implementing...Contaminants in Waterbirds and Effects on Avian Reproduction
California’s Central Valley and San Francisco Bay Estuary have a long history of mercury contamination from past mercury mining and gold extraction. Waterbirds are particularly susceptible to mercury because of their use of wetland habitats where methylmercury (the most toxic and biologically available form) is produced and relatively low methylmercury exposure can reduce reproductive success...Efficacy of Eggshell Analyses as a Nonlethal Method to Estimate Mercury Exposure in Bird Embryos
U.S. Geological Survey (USGS) scientists evaluated a nonlethal method to estimate mercury in the embryos of 23 bird species using mercury content in eggshells. This method was effective for a wide range of ages and species.Dixon Field Station
WERC scientists at the Dixon Field Station conduct studies from the San Francisco Bay-Delta in California to the Great Basin spanning California and Nevada. - Data
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Nocturnal Incubation Recess and Flushing Behavior by Duck Hens Nesting in Grizzly Island Wildlife Area 2015-2018
This dataset describes nocturnal incubation recess behavior for mallard and gadwall hens nesting in Grizzly Island Wildlife Area in breeding seasons 2015-2018. It includes the frequency, start time and duration of recesses, and details a method for determining whether a recess was initiated in response to a predator at the nest using nest temperature data. These data support the following pubMigration stopover ecology of cinnamon teal in western North America
Identifying migration routes and fall stopover sites of cinnamon teal (Spatula cyanoptera septentrionalium) can provide a spatial guide to management and conservation efforts, and address vulnerabilities in wetland networks that support migratory waterbirds. Using high spatio-temporal resolution GSM-GPS transmitters, we tracked the fall migration of 61 cinnamon teal across western North America ovEgg Morphometric Data Obtained for White-faced Ibis Nesting in Bear River Migratory Bird Refuge, Great Salt Lake, Utah (2010-2012)
This data consists of egg morphometric data from white-faced ibis. Eggs were collected in the field and then measured and dissected in the lab to obtain estimates of length, width and mass. This data supports the following publication: Herzog, M.P., Ackerman, J.T. and Hartman, C.A., 2021. Egg morphometrics and egg shape coefficients for White-faced Ibis (Plegadis chihi). The Wilson JournalHow Mallard and Gadwall Hens Nesting in Grizzly Island Wildlife Area Respond when Flushed (2015 - 2018)
This dataset describes responses to flushes by surveyors and predators for mallard and gadwall hens nesting on the Grizzly Island Wildlife Area, Suisun Marsh, California in 2015 through 2018. It includes the start time and duration of recesses, as well as the cause of recess initiation and responses of hens to various trapping activities at the nest site. These data support the following publBreeding Waterbird Populations in South San Francisco Bay 2005-2019
The dataset includes three separate excel spreadsheets which provides waterbird (and predator) observations within individual survey units during the May 2019 breeding waterbird survey of south San Francisco Bay (2019WaterbirdSurveyFullData.xlsx), the total number of American avocets, black-necked stilts, and Forster's terns within each pond unit surveyed during the May 2019 survey (2019WaterbirdSMercury Concentrations in Western Gulls along the West Coast, USA, 2015-2017
We investigated whether foraging habitat, sex, or fidelity to a foraging area effected blood mercury concentrations in western gulls (Larus occidentalis) from three colonies on the west coast of the United States. Dataset includes total mercury concentrations in western gulls from three colony locations and associated foraging habitat of individual gulls. These data support the following publicHair and blood total mercury concentrations in raccoons and striped skunks from Suisun Marsh 2016 to 2019
Total mercury concentrations were determined in hair and whole blood of raccoons and skunks in Suisun Marsh from 2016 to 2019. Individual skunks and raccoons were identified by a unique identifier (Animal_ID) and some animals were sampled multiple times. This dataset includes animal sex, age class, the date the sample was collected, animal body mass, head length, and head-to-torso length. TheAvian Eggshell Thickness for 12 Species in the Western U.S. from 2014 to 2018
Eggshell thickness was measured at the egg equator and poles (sharp pole and blunt pole) for 12 avian species. Eggshell thickness was related to egg morphometrics (egg length and width), embryonic development, egg status, and mercury contamination. Individual eggshells each have up to 3 thickness measurements, linked by the eggshell identification. Each measurement has the corresponding egg lengthMercury Bioaccumulation in US National Parks Using Dragonfly Larvae as Biosentinels, 2009-2018
Comma-separated values (.csv) files containing data related to a National-scale assessment of mercury bioaccumulation in the US National Parks using dragonfly larvae as biosentinels through a citizen science framework.Nest data for white-faced Ibis in Bear River Migratory Bird Refuge, Great Salt Lake, Utah in summer 2012
Nest monitoring data of white-faced ibis. Data were collected at seven day intervals and provide information on success and failure of the nest during that interval. Summary vegetation and habitat data were also collected at the nest. These data support the following publication: Mark P. Herzog, Ackerman, Joshua T., Hartman, C. Alex, and Browers, Howard, 2020, Nesting ecology of White-facedMercury and selenium concentrations in bird eggs at Great Salt Lake, Utah
These metadata provide data used to examine mercury and selenium concentrations in eggs of birds breeding in wetlands of the Great Salt Lake ecosystem, Utah, particularly at Bear River Migratory Bird Refuge. Eggs were salvaged during 2010 - 2012 and include 33 species of birds. These data support the following publication: Ackerman, J.T., Herzog, M.P., Hartman, C.A., Isanhart, J., Herring,Temporal 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) g - Multimedia
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Re-establishing Waterbird Breeding Colonies in San Francisco Bay
This U.S. Geological Survey (USGS), Western Ecological Research Center (WERC) story map details how partners are using science and management to maintain and establish new bird nesting colonies in support of the South Bay Salt Pond Restoration Project. Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government.
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