Thomas Custer (Former Employee)
Science and Products
Wildlife Toxicology
The team's long term goal is:
- Examine the causes, fates, exposures, biological accumulation, and adverse effects (including sublethal effects) of environmental contaminants on animal (largely bird) populations.
Systematic Approach to Understanding Tree Swallow Health in the Great Lakes Region—Science to Inform Restoration
Four papers by U.S. Geological Survey (USGS) scientists document tree swallow (Tachycineta bicolor) chemical exposure, physiological responses, and reproductive success in the Great Lakes region. These studies were designed to understand if there are health threats to swallows from contaminant exposure, and to provide resource managers with information about the actual as opposed to...
Birds as Indicators of Contaminant Exposure in the Great Lakes
Perfluoroalkyl contaminant exposure in tree swallows nesting at Clarks Marsh, Oscoda, Michigan, USA
A site in north eastern Michigan, Oscoda Township, has some of the highest recorded exposure in birds to perfluorinated substances (PFASs) in the U.S. Some egg and plasma concentrations at that location exceeded the lowest reproductive effect threshold established for two avian laboratory species. The objectives of this study were to determine...
Custer, Christine M.; Custer, Thomas W.; Delaney, Robert; Dummer, Paul; Schultz, Sandra L.; Karouna-Renier, Natalie K. Element concentrations in tree swallows (Tachycineta bicolor) from the U.S. and Binational Great Lakes’ areas of concern
Selected elements were targeted in state Remedial Action Plans as one group of chemicals affecting the Beneficial Use Impairments of Great Lakes Areas of Concern (AOC). Livers of nestling tree swallows, Tachycineta bicolor, were harvested from 76 sites in the Great Lakes which included multiple sites at 27 AOCs and 12 reference sites from 2010...
Custer, Thomas W.; Custer, Christine M.; Dummer, Paul; Goldberg, Diana R.; Franson, J. Christian Reproductive success and contaminant associations in tree swallows (Tachycineta bicolor) used to assess a Beneficial Use Impairment in U.S. and Binational Great Lakes’ Areas of Concern
During 2010-2014, tree swallow (Tachycineta bicolor) reproductive success was monitored at 68 sites across all 5 Great Lakes, including 58 sites located within Great Lakes Areas of Concern (AOCs) and 10 non-AOCs. Sample eggs were collected from tree swallow clutches and analyzed for contaminants including polychlorinated biphenyls (PCBs), dioxins...
Custer, Christine M.; Custer, Thomas W.; Etterson, Matthew A.; Dummer, Paul; Goldberg, Diana R.; Franson, J. Christian Annual variation in polychlorinated biphenyl (PCB) exposure in tree swallow (Tachycineta bicolor) eggs and nestlings at Great Lakes Restoration Initiative (GLRI) study sites
Tree swallow (Tachycineta bicolor) eggs and nestlings were collected from 16 sites across the Great Lakes to quantify normal annual variation in total polychlorinated biphenyl (PCB) exposure and to validate the sample size choice in earlier work. A sample size of five eggs or five nestlings per site was adequate to quantify exposure to PCBs in...
Custer, Christine M.; Custer, Thomas W.; Dummer, Paul; Goldberg, Diana R.; Franson, J. Christian
Synthesis of tree swallow (Tachycineta bicolor) data for Beneficial Use Impairment (BUI) assessment at Wisconsin Areas of Concern
Assessment of the “Bird or Animal Deformities or Reproductive Problems” Beneficial Use Impairment (BUI) can be accomplished by (1) comparing tissue concentrations to established background and Lowest Observable Effect Level (LOEL) for reproductive effects, or (2) directly measuring reproductive success at Areas of Concern (AOCs) and statistically...
Custer, Christine M.; Custer, Thomas W.; Dummer, Paul EROD activity, chromosomal damage, and oxidative stress in response to contaminants exposure in tree swallow (Tachycineta bicolor) nestlings from Great Lakes Areas of Concern
Tree swallow, Tachycineta bicolor, nestlings were collected from 60 sites in the Great Lakes, which included multiple sites within 27 Areas of Concern (AOCs) and six sites not listed as AOCs from 2010 to 2014. Nestlings, approximately 12 days-of-age, were evaluated for ethoxyresorufin-O-dealkylase (EROD) activity, chromosomal damage, and six...
Custer, Thomas W.; Custer, Christine M.; Dummer, Paul; Bigorgne, Emilie; Oziolor, Elias; Karouna-Renier, Natalie K.; Schultz, Sandra L.; Erickson, Richard A.; Aagaard, Kevin; Matson, Cole W. Organic contamination in tree swallow (Tachycineta bicolor) nestlings at United States and binational great Lakes Areas of Concern
Contaminant exposure of tree swallows, Tachycineta bicolor, nesting in 27 Areas of Concern (AOCs) in the Great Lakes basin was assessed from 2010 to 2014 to assist managers and regulators in their assessments of Great Lakes AOCs. Contaminant concentrations in nestlings from AOCs were compared with those in nestlings from nearby non-AOC sites....
Custer, Thomas W.; Custer, Christine M.; Dummer, Paul; Goldberg, Diana R.; Franson, J. Christian; Erickson, Richard A. Concentrations and spatial patterns of organic contaminants in tree swallow (Tachycineta bicolor) eggs at United States and binational Great Lakes Areas of Concern, 2010–2015
Tree swallows, Tachycineta bicolor, were sampled across the Great Lakes basin in 2010 through 2015 to provide a system-wide assessment of current exposure to organic contaminants. The results provide information identified as critical by regulators to assess the “bird or animal deformity or reproductive problems” beneficial use...
Custer, Christine M.; Custer, Thomas W.; Dummer, Paul; Goldberg, Diana R.; Franson, J. Christian Mercury concentrations in eggs of red-winged blackbirds and tree swallows breeding in Voyageurs National Park, Minnesota
Most investigations of the environmental effects of mercury (Hg) have focused on aquatic food webs that include piscivorous fish or wildlife. However, recent investigations have shown that other species, including passerine songbirds, may also be at risk from exposure to methylmercury (MeHg). We quantified Hg concentrations in eggs of two species...
Tyser, Robin W.; Rolfhus, Kristofer R.; Wiener, James G.; Windels, Steve K.; Custer, Thomas W.; Dummer, Paul Chromosomal damage and EROD induction in tree swallows (Tachycineta bicolor) along the Upper Mississippi River, Minnesota, USA
The health of tree swallows, Tachycineta bicolor, on the Upper Mississippi River (UMR) was assessed in 2010 and 2011 using biomarkers at six sites downriver of Minneapolis/St. Paul, MN metropolitan area, a tributary into the UMR, and a nearby lake. Chromosomal damage was evaluated in nestling blood by measuring the coefficient of...
Bigorgne, Emilie; Custer, Thomas W.; Dummer, Paul; Erickson, Richard A.; Karouna-Renier, Natalie K.; Schultz, Sandra L.; Custer, Christine M.; Thogmartin, Wayne E.; Matson, Cole W. Incubation stage and polychlorinated biphenyl (PCB) congener patterns in an altricial and precocial bird species
The composition of polychlorinated biphenyl (PCB) congeners was compared between non-incubated and embryonated eggs of tree swallows (Tachycineta bicolor) and little terns (Sterna albifrons) to determine if measurable changes in PCB congeners occurred during the embryonic period. There was no indication of changes in PCB congener patterns over the...
Custer, Christine M.; Custer, Thomas W.; Thyen, Stefan; Becker, Peter H. Contaminant exposure of birds nesting in Green Bay, Wisconsin, USA
In earlier studies, elevated concentrations of polychlorinated biphenyl (PCB) and p,p'-dichlorodiphenyldichloroethylene (DDE) were reported in double-crested cormorant (Phalacrocorax auritus) eggs and tree swallow (Tachycineta bicolor) eggs and nestlings collected from lower Green Bay (WI, USA) in 1994 and 1995 and black-crowned night-heron (...
Custer, Thomas W.; Dummer, Paul M.; Custer, Christine M.; Franson, J. Christian; Jones, Michael