Christopher "Alex" Hartman
Dr. Alex Hartman is a Wildlife Biologist with the USGS Western Ecological Research Center at the Dixon Field Station. His interests and expertise are in waterbird ecology, wetlands, behavioral ecology, breeding biology, and the effects of contaminants on avian ecology and reproduction.
Education:
- Ph.D., Ecology, Evolution and Conservation Biology, University of Nevada, Reno, 2008
- M.Sc., Environmental and Natural Resource Sciences, University of Nevada, Reno, 2003
- B.Sc., Biological Sciences, University of California, Davis, 1997
Professional Experience:
- Wildlife Biologist, U.S. Geological Survey, Western Ecological Research Center, Dixon Field Station, California (2013-present)
- Wildlife Biologist, U.S. Geological Survey, Western Ecological Research Center, UC Davis Field Station, California (2011-2013)
- Shorebird Conservation Biologist, Audubon California, Sacramento, California (2009-2011)
- Landbird Program Supervisor, San Francisco Bay Bird Observatory, Milpitas, California (2009)
- Doctoral Research, Program in Ecology, Evolution and Conservation Biology, University of Nevada, Reno (2003-2008)
- Masters Research, Department of Environmental and Natural Resource Sciences, University of Nevada, Reno (2000-2003)
Publications:
2019
Hartman CA, JT Ackerman, MP Herzog, C Strong, and D Trachtenbarg. 2019. Social attraction used to establish Caspian tern nesting colonies in San Francisco Bay. Global Ecology and Conservation 20: e00757.
Hartman CA, JT Ackerman, and MP Herzog. 2019. Mercury exposure and altered parental nesting behavior in a wild songbird. Environmental Science & Technology 53:5396–5405.
Ackerman JT, CA Hartman, and MP Herzog. 2019. Mercury contamination in resident and migrant songbirds and potential effects on body condition. Environmental Pollution 246:797-810.
McDuie F, ML Casazza, CT Overton, MP Herzog, CA Hartman, SH Peterson, CL Feldheim, and JT Ackerman. 2019. GPS tracking data reveals daily spatio-temporal movement patterns of waterfowl. Movement Ecology 7:6.
Peterson SP, JT Ackerman, MP Herzog, CA Hartman, R Croston, CL Feldheim, and ML Casazza. 2019. Sitting ducklings: Timing of hatch, nest departure, and predation risk for dabbling duck broods. Ecology and Evolution 9:5490–5500.
2018
Croston R, CA Hartman, MP Herzog, ML Casazza, and JT Ackerman. 2018. A new approach to automated incubation recess detection using temperature loggers. Condor 120:739–750.
Peterson SH, JT Ackerman, CA Eagles-Smith, MP Herzog, and CA Hartman. 2018. Prey fish returned to Forster’s tern colonies suggest spatial and temporal differences in fish composition and availability. PLoS ONE 13(3):e0193430.
Science and Products
It’s what’s inside that counts: Egg contaminant concentrations are influenced by estimates of egg density, egg volume, and fresh egg mass
Maternal transfer of contaminants in birds: Mercury and selenium concentrations in parents and their eggs
Science foundation Chapter 5 Appendix 5.1: Case study Forester's tern (Sterna forsteri) and California least tern (Sternula antillarum browni)
Estimating mercury exposure of piscivorous birds and sport fish using prey fish monitoring
Egg laying sequence influences egg mercury concentrations and egg size in three bird species: Implications for contaminant monitoring programs
Estimating exposure of piscivorous birds and sport fish to mercury in California lakes using prey fish monitoring: a predictive tool for managers
Experimental dosing of wetlands with coagulants removes mercury from surface water and decreases mercury bioaccumulation in fish
The critical role of islands for waterbird breeding and foraging habitat in managed ponds of the South Bay Salt Pond Restoration Project, South San Francisco Bay, California
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It’s what’s inside that counts: Egg contaminant concentrations are influenced by estimates of egg density, egg volume, and fresh egg mass
In egg contaminant studies, it is necessary to calculate egg contaminant concentrations on a fresh wet weight basis and this requires accurate estimates of egg density and egg volume. We show that the inclusion or exclusion of the eggshell can influence egg contaminant concentrations, and we provide estimates of egg density (both with and without the eggshell) and egg-shape coefficients (used to eAuthorsMark P. Herzog, Joshua T. Ackerman, Collin A. Eagles-Smith, C. Alex HartmanMaternal transfer of contaminants in birds: Mercury and selenium concentrations in parents and their eggs
We conducted a detailed assessment of the maternal transfer of mercury and selenium to eggs in three bird species (n = 107 parents and n = 339 eggs), and developed predictive equations linking contaminant concentrations in eggs to those in six tissues of the mother (blood, muscle, liver, kidney, breast feathers, and head feathers). Mercury concentrations in eggs were positively correlated with merAuthorsJoshua T. Ackerman, Collin A. Eagles-Smith, Mark P. Herzog, C. Alex HartmanScience foundation Chapter 5 Appendix 5.1: Case study Forester's tern (Sterna forsteri) and California least tern (Sternula antillarum browni)
This case study considers two tern species that breed within the San Francisco Bay Estuary, Forster’s Terns (Sterna forsteri) and California Least Terns (Sternula antillarum browni). Forster’s Terns are medium-sized (140 g) terns that breed in coastal and interior marshes of North America. Forster’s Terns can exploit ephemeral habitats, and colony locations often move among years with change in haAuthorsJoshua T. Ackerman, C. Alex Hartman, Cheryl StrongEstimating mercury exposure of piscivorous birds and sport fish using prey fish monitoring
Methylmercury is a global pollutant of aquatic ecosystems, and monitoring programs need tools to predict mercury exposure of wildlife. We developed equations to estimate methylmercury exposure of piscivorous birds and sport fish using mercury concentrations in prey fish. We collected original data on western grebes (Aechmophorus occidentalis) and Clark’s grebes (Aechmophorus clarkii) and summarizeAuthorsJoshua T. Ackerman, C. Alex Hartman, Collin A. Eagles-Smith, Mark P. Herzog, Jay Davis, Gary Ichikawa, Autumn BonnemaEgg laying sequence influences egg mercury concentrations and egg size in three bird species: Implications for contaminant monitoring programs
Bird eggs are commonly used in contaminant monitoring programs and toxicological risk assessments, but intra-clutch variation and sampling methodology could influence interpretability. We examined the influence of egg laying sequence on egg mercury concentrations and burdens in American avocets, black-necked stilts, and Forster's terns. The average decline in mercury concentrations between the firAuthorsJoshua T. Ackerman, Collin A. Eagles-Smith, Mark P. Herzog, Julie L. Yee, C. Alex HartmanEstimating exposure of piscivorous birds and sport fish to mercury in California lakes using prey fish monitoring: a predictive tool for managers
Numerous water bodies in California are listed under the Clean Water Act as being impaired due to mercury (Hg) contamination. The Surface Water Ambient Monitoring Program (SWAMP), via the Bioaccumulation Oversight Group (BOG), has recently completed statewide surveys of contaminants in sport fish tissue from more than 250 lakes and rivers in California and throughout coastal waters. This effort foAuthorsJoshua T. Ackerman, C. Alex Hartman, Collin A. Eagles-Smith, Mark P. Herzog, Jay Davison, Gary Ichikawa, Autumn BonnemaExperimental dosing of wetlands with coagulants removes mercury from surface water and decreases mercury bioaccumulation in fish
Mercury pollution is widespread globally, and strategies for managing mercury contamination in aquatic environments are necessary. We tested whether coagulation with metal-based salts could remove mercury from wetland surface waters and decrease mercury bioaccumulation in fish. In a complete randomized block design, we constructed nine experimental wetlands in California’s Sacramento–San Joaquin DAuthorsJoshua T. Ackerman, Tamara E.C. Kraus, Jacob A. Fleck, David P. Krabbenhoft, William R. Horwarth, Sandra M. Bachand, Mark P. Herzog, C. Alex Hartman, Philip A.M. BachandThe critical role of islands for waterbird breeding and foraging habitat in managed ponds of the South Bay Salt Pond Restoration Project, South San Francisco Bay, California
The South Bay Salt Pond Restoration Project aims to restore 50–90 percent of former salt evaporation ponds into tidal marsh in South San Francisco Bay, California. However, large numbers of waterbirds use these ponds annually as nesting and foraging habitat. Islands within ponds are particularly important habitat for nesting, foraging, and roosting waterbirds. To maintain current waterbird populatAuthorsJoshua T. Ackerman, C. Alex Hartman, Mark P. Herzog, Lacy M. Smith, Stacy M. Moskal, Susan E.W. De La Cruz, Julie L. Yee, John Y. Takekawa - News