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
A new approach to automated incubation recess detection using temperature loggers
Social attraction used to establish Caspian tern (Hydroprogne caspia) nesting colonies on modified islands at the Don Edwards San Francisco Bay National Wildlife Refuge, California—Final report
Duck nest depredation, predator behavior, and female response using video
Evaluation of social attraction measures to establish Forster’s tern (Sterna forsteri) nesting colonies for the South Bay Salt Pond Restoration Project, San Francisco Bay, California—2017 Annual Report
Prey fish returned to Forster’s tern colonies suggest spatial and temporal differences in fish composition and availability
Maternal transfer of mercury to songbird eggs
Season, molt, and body size influence mercury concentrations in grebes
A critical evaluation of the utility of eggshells for estimating mercury concentrations in avian eggs
Island characteristics within wetlands influence waterbird nest success and abundance
Waterbird nest-site selection is influenced by neighboring nests and island topography
Avian mercury exposure and toxicological risk across western North America: A synthesis
Differentiating sex and species of Western Grebes (Aechmophorus occidentalis) and Clark's Grebes (Aechmophorus clarkii) and their eggs using external morphometrics and discriminant function analysis
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A new approach to automated incubation recess detection using temperature loggers
Nest attendance during incubation is an important facet of avian nesting behavior, and understanding the number, timing, and duration of incubation recesses can improve our understanding of the factors determining avian reproductive success. Temperature loggers are a low-cost, noninvasive method for studying nest attendance, but processing and interpreting the data present logistical challenges foAuthorsRebecca Croston, C. Alex Hartman, Mark P. Herzog, Michael L. Casazza, Joshua T. AckermanSocial attraction used to establish Caspian tern (Hydroprogne caspia) nesting colonies on modified islands at the Don Edwards San Francisco Bay National Wildlife Refuge, California—Final report
To address the 2008/2010 and Supplemental 2014 National Oceanic and Atmospheric Administration Fisheries Biological Opinion for operation of the Federal Columbia River Power System, the U.S. Army Corps of Engineers (USACE) and the Bureau of Reclamation (Reclamation) developed and began implementation of Caspian tern (Hydroprogne caspia) management plans. This implementation includes redistributionAuthorsC. Alex Hartman, Joshua T. Ackerman, Mark P. Herzog, Cheryl Strong, David Trachtenbarg, Crystal A. ShoreDuck nest depredation, predator behavior, and female response using video
Depredation plays an important role in determining duck nest success and predator and female duck behavior during nest depredation can influence nest fate. We examined depredation of mallard (Anas platyrhynchos) and gadwall (A. strepera) nests in Suisun Marsh, California, USA, in 2015–2016 with continuous infrared video monitoring to identify nest predators and characterize predator and female ducAuthorsRebecca Croston, Joshua T. Ackerman, Mark P. Herzog, Jeffrey D. Kohl, C. Alex Hartman, Sarah H. Peterson, Cory T. Overton, Cliff L. Feldheim, Michael L. CasazzaEvaluation of social attraction measures to establish Forster’s tern (Sterna forsteri) nesting colonies for the South Bay Salt Pond Restoration Project, San Francisco Bay, California—2017 Annual Report
Forster’s terns (Sterna forsteri), historically one of the most numerous colonial-breeding waterbirds in South San Francisco Bay, California, have had recent decreases in the number of nesting colonies and overall breeding population size. The South Bay Salt Pond (SBSP) Restoration Project aims to restore 50–90 percent of former salt evaporation ponds to tidal marsh habitat in South San FranciscoAuthorsC. Alex Hartman, Joshua T. Ackerman, Mark P. Herzog, Yiwei Wang, Cheryl StrongPrey fish returned to Forster’s tern colonies suggest spatial and temporal differences in fish composition and availability
Predators sample the available prey community when foraging; thus, changes in the environment may be reflected by changes in predator diet and foraging preferences. We examined Forster’s tern (Sterna forsteri) prey species over an 11-year period by sampling approximately 10,000 prey fish returned to 17 breeding colonies in south San Francisco Bay, California. We compared the species composition amAuthorsSarah H. Peterson, Joshua T. Ackerman, Collin A. Eagles-Smith, Mark P. Herzog, C. Alex HartmanMaternal transfer of mercury to songbird eggs
We evaluated the maternal transfer of mercury to eggs in songbirds, determined whether this relationship differed between songbird species, and developed equations for predicting mercury concentrations in eggs from maternal blood. We sampled blood and feathers from 44 house wren (Troglodytes aedon) and 34 tree swallow (Tachycineta bicolor) mothers and collected their full clutches (n = 476 eggs) wAuthorsJoshua T. Ackerman, C. Alex Hartman, Mark P. HerzogSeason, molt, and body size influence mercury concentrations in grebes
We studied seasonal and physiological influences on mercury concentrations in western grebes (Aechmophorus occidentalis) and Clark's grebes (A. occidentalis) across 29 lakes and reservoirs in California, USA. Additionally, at three of these lakes, we conducted a time series study, in which we repeatedly sampled grebe blood mercury concentrations during the spring, summer, and early fall. Grebe bloAuthorsC. Alex Hartman, Joshua T. Ackerman, Mark P. Herzog, Collin A. Eagles-SmithA critical evaluation of the utility of eggshells for estimating mercury concentrations in avian eggs
Eggshells are a potential tool for non-lethally sampling contaminant concentrations in bird eggs, yet few studies have examined their utility to represent mercury exposure. We assessed mercury concentrations in eggshell components for 23 bird species and determined whether they correlated with total mercury (THg) in egg contents. We designed a multi-experiment analysis to examine how THg is partitAuthorsSarah H. Peterson, Joshua T. Ackerman, Collin A. Eagles-Smith, C. Alex Hartman, Mark P. HerzogIsland characteristics within wetlands influence waterbird nest success and abundance
Coastal waterbird populations are threatened by habitat loss and degradation from urban and agricultural development and forecasted sea level rise associated with climate change. Remaining wetlands often must be managed to ensure that waterbird habitat needs, and other ecosystem functions, are met. For many waterbirds, the availability of island nesting habitat is important for conserving breedingAuthorsC. Alex Hartman, Joshua T. Ackerman, Mark P. HerzogWaterbird nest-site selection is influenced by neighboring nests and island topography
Avian nest-site selection is influenced by factors operating across multiple spatial scales. Identifying preferred physical characteristics (e.g., topography, vegetation structure) can inform managers to improve nesting habitat suitability. However, social factors (e.g., attraction, territoriality, competition) can complicate understanding physical characteristics preferred by nesting birds. We siAuthorsC. Alex Hartman, Joshua T. Ackerman, John Y. Takekawa, Mark P. HerzogAvian mercury exposure and toxicological risk across western North America: A synthesis
Methylmercury contamination of the environment is an important issue globally, and birds are useful bioindicators for mercury monitoring programs. The available data on mercury contamination of birds in western North America were synthesized. Original data from multiple databases were obtained and a literature review was conducted to obtain additional mercury concentrations. In total, 29219 origiAuthorsJoshua T. Ackerman, Collin A. Eagles-Smith, Mark P. Herzog, C. Alex Hartman, Sarah H. Peterson, David C. Evers, Allyson K. Jackson, John E. Elliott, Stacy S. Vander Pol, Colleen E. BryanDifferentiating sex and species of Western Grebes (Aechmophorus occidentalis) and Clark's Grebes (Aechmophorus clarkii) and their eggs using external morphometrics and discriminant function analysis
In birds where males and females are similar in size and plumage, sex determination by alternative means is necessary. Discriminant function analysis based on external morphometrics was used to distinguish males from females in two closely related species: Western Grebe (Aechmophorus occidentalis) and Clark's Grebe (A. clarkii). Additionally, discriminant function analysis was used to evaluate morAuthorsC. Alex Hartman, Joshua T. Ackerman, Collin A. Eagles-Smith, Mark P. Herzog - News