Thomas Custer (Former Employee)
Science and Products
Filter Total Items: 179
Reproductive success of barn swallows nesting near a selenium-contaminated lake in east Texas, USA
Reproductive success and contaminant levels in 1986 and 1987 were compared between Barn Swallows nesting at selenium-contaminated Martin Lake, Texas, USA, and swallows nesting at a reference site. Nests were initiated about the same time or earlier at Martin Lake than at the reference site and clutch size was similar between the two locations. Nest success was significantly higher at Martin Lake t
Authors
K. A. King, T. W. Custer, D.A. Weaver
Flow cytometry for monitoring contaminant exposure in black-crowned night-herons
The flow cytometry method (FCM) was employed to determine cellular DNA content of black-crowned night-heron (Nycticorax nycticorax) embryos and 10-day-old chicks collected at sites differing in types of chemical contamination. The coefficient of variation of DNA content (CV) in blood collected from embryos suggested cytogenetic damage at a site in Louisiana known to be contaminated with petrole
Authors
T. W. Custer, J. W. Bickham, T.B. Lyne, T. Lewis, L.A. Ruedas, Christine M. Custer, M. J. Melancon
Prevalence of eustrongylidosis in wading birds from colonies in California, Texas, and Rhode Island, USA
Snowy Egret (Egretta thula) and Black-crowned Night-Heron (Nycticorax nycticorax) nestlings from colonies in Texas, Rhode Island, and California and Great Egret (Casmerodius albus) nestlings from Texas were examined for eustrongylidosis, or infection by the parasitic nematode Eustrongylides spp. In 31% (24/77) of all broods examined, at least one nestling was infected. Snowy Egret broods from Texa
Authors
J. C. Franson, T. W. Custer
Relation among cytochrome P450, AH-active PCB congeners and dioxin equivalents in pipping black-crowned night-heron embryos
Pipping black-crowned night-heron (Nycticorax nycticorax) embryos were collected from a relatively uncontaminated site (next to Chincoteague National Wildlife Refuge, VA) and three polluted sites (Cat Island, Green Bay, Lake Michigan, WI; Bair Island, San Francisco Bay, CA; West Marin Island, San Francisco Bay, CA). Hepatic cytochrome P-450-associated monooxygenases and cytochrome P-450 proteins,
Authors
Barnett A. Rattner, J. S. Hatfield, M. J. Melancon, T. W. Custer, D. E. Tillitt
Herbivory on shoalgrass by wintering redheads in Texas
An estimated 80% of redheads (Aythya americana) winter on the Laguna Madre of south Texas and Mexico and feed almost exclusively on shoalgrass (Halodule wrightii) rhizomes. Shoalgrass abundance has decreased by 60% over the past 30 years, and because the effects of shoalgrass loss on wintering redheads are unknown, we initiated a study to define habitat selection criteria and document the effect
Authors
C. A. Mitchell, T. W. Custer, P.J. Zwank
Trace elements in canvasbacks (Aythya valisineria) wintering in Louisiana, USA, 1987-1988
We determined trace element concentrations in livers of canvasbacks (Aythya valisineria) collected at Catahoula Lake and the Mississippi River Delta, Louisiana during, the winter of 1987–1988. Forty percent of canvasbacks wintering at Lake Catahoula had elevated concentrations of lead (>6·7 μg g−1 dry weight) in the liver; 33% had concentrations consistent with lead intoxication (>26·7 μg g−1). Ba
Authors
Thomas W. Custer, William L. Hohman
Environmental contaminants in redheads wintering in coastal Louisiana and Texas
Whole body and liver analyses indicated that wintering redheads (Aythya americana; n = 70) in coastal Louisiana (one site) and Texas (two sites) were relatively free of contamination with common trace elements, organochlorines, and hydrocarbons. Most trace elements, including As, Cr, Hg, Mg, Mn, Ni, Pb, Se, Sr, and Zn, were within background concentrations in livers; levels of B, Cd, Cu, and Fe
Authors
T.C. Michot, T. W. Custer, A.J. Nault, C. A. Mitchell
Biomonitoring environmental contamination with pipping black-crowned night heron embryos: Induction of cytochrome P450
Cytochrome P450-associated monooxygenase activities and cytochrome P450 proteins were measured in pipping black-crowned night heron (Nycticorax nycticorax) embryos collected from a reference site (next to the Chincoteague National Wildlife Refuge, VA) and three polluted sites (Cat Island, Green Bay, Lake Michigan, WI; Bair Island, San Francisco Bay, CA; West Marin Island, San Francisco Bay, CA). I
Authors
Barnett A. Rattner, M. J. Melancon, T. W. Custer, R. L. Hothem, K. A. King, L. J. LeCaptain, J. W. Spann, Bruce R. Woodin, John J. Stegeman
Biomonitoring environmental contamination with pipping black-crowned night heron embryos: Induction of cytochrome P450
Cytochrome P450-associated monooxygenase activities and cytochrome P450 proteins were measured in pipping black-crowned night heron (Nycticorax nycticorax) embryos collected from a reference site (next to the Chincoteague National Wildlife Refuge, VA) and three polluted sites (Cat Island, Green Bay, Lake Michigan, WI; Bair Island, San Francisco Bay, CA; West Marin Island, San Francisco Bay, CA).
Authors
Barnett A. Rattner, M. J. Melancon, T. W. Custer, R. L. Hothem, K. A. King, L. J. LeCaptain, J. W. Spann, Bruce R. Woodin, John J. Stegeman
Relationships among cytochromes P450 and dioxin equivalents in pipping heron embryos from Virginia, the Great Lakes and San Francisco Bay
Pipping black-crowned night-heron (Nycticorax nycticorax) embryos were collected from undisturbed (Chincoteague National Wildlife Refuge, VA) and industrialized (Cat Island, Green Bay, WI; San Francisco Bay, CA) locations. Hepatic P450 associated monooxygenases (AHH, EROD, BROD, ECOD) and P450 proteins (CYP1A, CYP2B) were induced up to 85-fold, and were associated with burdens of total PCBs and 11
Authors
Barnett A. Rattner, J. S. Hatfield, M. J. Melancon, T. W. Custer, D.E. Tillett
Trace elements and organochlorines in the shoalgrass community of the lower Laguna Madre Texas
Our objectives were to measure concentrations of seven trace elements and 14 organochlorine compounds in sediment and biota of the shoalgrass (Halodule wrightii) community of the lower Laguna Madre of south Texas and to determine whether chemicals associated with agriculture (e.g. mercury, arsenic, selenium, organochlorine pesticides) were highest near agricultural drainages. Arsenic, mercury, sel
Authors
T. W. Custer, C. A. Mitchell
Feeding flights of breeding double-crested cormorants at two Wisconsin colonies
Unmarked Double-crested Cormorants (Phalacrocorax auritus) (n = 523) were followed by airplane from Cat Island and Spider Island, two nesting colonies in Wisconsin, to their first landing site. Cormorants flew an average of 2.0 km from Cat Island (maximum 40 km) and 2.4 km from Spider Island (maximum12 km). The mean direction of landing sites differed seasonally for fights from Spider Island, bu
Authors
T. W. Custer, C. Bunck
Science and Products
Filter Total Items: 179
Reproductive success of barn swallows nesting near a selenium-contaminated lake in east Texas, USA
Reproductive success and contaminant levels in 1986 and 1987 were compared between Barn Swallows nesting at selenium-contaminated Martin Lake, Texas, USA, and swallows nesting at a reference site. Nests were initiated about the same time or earlier at Martin Lake than at the reference site and clutch size was similar between the two locations. Nest success was significantly higher at Martin Lake t
Authors
K. A. King, T. W. Custer, D.A. Weaver
Flow cytometry for monitoring contaminant exposure in black-crowned night-herons
The flow cytometry method (FCM) was employed to determine cellular DNA content of black-crowned night-heron (Nycticorax nycticorax) embryos and 10-day-old chicks collected at sites differing in types of chemical contamination. The coefficient of variation of DNA content (CV) in blood collected from embryos suggested cytogenetic damage at a site in Louisiana known to be contaminated with petrole
Authors
T. W. Custer, J. W. Bickham, T.B. Lyne, T. Lewis, L.A. Ruedas, Christine M. Custer, M. J. Melancon
Prevalence of eustrongylidosis in wading birds from colonies in California, Texas, and Rhode Island, USA
Snowy Egret (Egretta thula) and Black-crowned Night-Heron (Nycticorax nycticorax) nestlings from colonies in Texas, Rhode Island, and California and Great Egret (Casmerodius albus) nestlings from Texas were examined for eustrongylidosis, or infection by the parasitic nematode Eustrongylides spp. In 31% (24/77) of all broods examined, at least one nestling was infected. Snowy Egret broods from Texa
Authors
J. C. Franson, T. W. Custer
Relation among cytochrome P450, AH-active PCB congeners and dioxin equivalents in pipping black-crowned night-heron embryos
Pipping black-crowned night-heron (Nycticorax nycticorax) embryos were collected from a relatively uncontaminated site (next to Chincoteague National Wildlife Refuge, VA) and three polluted sites (Cat Island, Green Bay, Lake Michigan, WI; Bair Island, San Francisco Bay, CA; West Marin Island, San Francisco Bay, CA). Hepatic cytochrome P-450-associated monooxygenases and cytochrome P-450 proteins,
Authors
Barnett A. Rattner, J. S. Hatfield, M. J. Melancon, T. W. Custer, D. E. Tillitt
Herbivory on shoalgrass by wintering redheads in Texas
An estimated 80% of redheads (Aythya americana) winter on the Laguna Madre of south Texas and Mexico and feed almost exclusively on shoalgrass (Halodule wrightii) rhizomes. Shoalgrass abundance has decreased by 60% over the past 30 years, and because the effects of shoalgrass loss on wintering redheads are unknown, we initiated a study to define habitat selection criteria and document the effect
Authors
C. A. Mitchell, T. W. Custer, P.J. Zwank
Trace elements in canvasbacks (Aythya valisineria) wintering in Louisiana, USA, 1987-1988
We determined trace element concentrations in livers of canvasbacks (Aythya valisineria) collected at Catahoula Lake and the Mississippi River Delta, Louisiana during, the winter of 1987–1988. Forty percent of canvasbacks wintering at Lake Catahoula had elevated concentrations of lead (>6·7 μg g−1 dry weight) in the liver; 33% had concentrations consistent with lead intoxication (>26·7 μg g−1). Ba
Authors
Thomas W. Custer, William L. Hohman
Environmental contaminants in redheads wintering in coastal Louisiana and Texas
Whole body and liver analyses indicated that wintering redheads (Aythya americana; n = 70) in coastal Louisiana (one site) and Texas (two sites) were relatively free of contamination with common trace elements, organochlorines, and hydrocarbons. Most trace elements, including As, Cr, Hg, Mg, Mn, Ni, Pb, Se, Sr, and Zn, were within background concentrations in livers; levels of B, Cd, Cu, and Fe
Authors
T.C. Michot, T. W. Custer, A.J. Nault, C. A. Mitchell
Biomonitoring environmental contamination with pipping black-crowned night heron embryos: Induction of cytochrome P450
Cytochrome P450-associated monooxygenase activities and cytochrome P450 proteins were measured in pipping black-crowned night heron (Nycticorax nycticorax) embryos collected from a reference site (next to the Chincoteague National Wildlife Refuge, VA) and three polluted sites (Cat Island, Green Bay, Lake Michigan, WI; Bair Island, San Francisco Bay, CA; West Marin Island, San Francisco Bay, CA). I
Authors
Barnett A. Rattner, M. J. Melancon, T. W. Custer, R. L. Hothem, K. A. King, L. J. LeCaptain, J. W. Spann, Bruce R. Woodin, John J. Stegeman
Biomonitoring environmental contamination with pipping black-crowned night heron embryos: Induction of cytochrome P450
Cytochrome P450-associated monooxygenase activities and cytochrome P450 proteins were measured in pipping black-crowned night heron (Nycticorax nycticorax) embryos collected from a reference site (next to the Chincoteague National Wildlife Refuge, VA) and three polluted sites (Cat Island, Green Bay, Lake Michigan, WI; Bair Island, San Francisco Bay, CA; West Marin Island, San Francisco Bay, CA).
Authors
Barnett A. Rattner, M. J. Melancon, T. W. Custer, R. L. Hothem, K. A. King, L. J. LeCaptain, J. W. Spann, Bruce R. Woodin, John J. Stegeman
Relationships among cytochromes P450 and dioxin equivalents in pipping heron embryos from Virginia, the Great Lakes and San Francisco Bay
Pipping black-crowned night-heron (Nycticorax nycticorax) embryos were collected from undisturbed (Chincoteague National Wildlife Refuge, VA) and industrialized (Cat Island, Green Bay, WI; San Francisco Bay, CA) locations. Hepatic P450 associated monooxygenases (AHH, EROD, BROD, ECOD) and P450 proteins (CYP1A, CYP2B) were induced up to 85-fold, and were associated with burdens of total PCBs and 11
Authors
Barnett A. Rattner, J. S. Hatfield, M. J. Melancon, T. W. Custer, D.E. Tillett
Trace elements and organochlorines in the shoalgrass community of the lower Laguna Madre Texas
Our objectives were to measure concentrations of seven trace elements and 14 organochlorine compounds in sediment and biota of the shoalgrass (Halodule wrightii) community of the lower Laguna Madre of south Texas and to determine whether chemicals associated with agriculture (e.g. mercury, arsenic, selenium, organochlorine pesticides) were highest near agricultural drainages. Arsenic, mercury, sel
Authors
T. W. Custer, C. A. Mitchell
Feeding flights of breeding double-crested cormorants at two Wisconsin colonies
Unmarked Double-crested Cormorants (Phalacrocorax auritus) (n = 523) were followed by airplane from Cat Island and Spider Island, two nesting colonies in Wisconsin, to their first landing site. Cormorants flew an average of 2.0 km from Cat Island (maximum 40 km) and 2.4 km from Spider Island (maximum12 km). The mean direction of landing sites differed seasonally for fights from Spider Island, bu
Authors
T. W. Custer, C. Bunck