Thomas Custer (Former Employee)
Science and Products
Filter Total Items: 185
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
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
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
Redhead duck behavior on lower Laguna Madre and adjacent ponds of southern Texas
Behavior of redheads (Aythya americana) during winter was studied on the hypersaline lower Laguna Madre and adjacent freshwater to brackish water ponds of southern Texas. On Laguna Madre, feeding (46%) and sleeping (37%) were the most common behaviors. Redheads fed more during early morning (64%) than during the rest of the day (40%); feeding activity was negatively correlated with temperature. Re
Authors
C. A. Mitchell, T. W. Custer, P.J. Zwank
Cytochrome P450 responses and PCB congeners in pipping heron embryos from Virginia, the Great Lakes and San Francisco Bay
Pipping black-crowned night-heron (Nvcticorax nvcticorax) embryos were collected from undisturbed (Chincoteague National Wildlife Refuge VA; CNWR) and industrialized (Cat Island, Green Bay WI and San Francisco Bay, CA; SFB) locations. Hepatic monooxygenases (AHH, EROD, BROD, ECOD) were induced up to 100-fold, and were correlated (r=0.50 to 0.72) with total PCB burdens (N =61 embryos). A subset of
Authors
Barnett A. Rattner, M. J. Melancon, T. W. Custer, D.E. Tillett, Bruce R. Woodin, John J. Stegeman
Determination of hatching date for eggs of black-crowned night-herons, snowy egrets and great egrets
Flotation of eggs in water and specific gravity of eggs of Black-crowned Night-Herons (Nycticorax nycticorax), Snowy Egrets (Egretta thula) and Great Egrets (Casmerodius albus) were evaluated as methods to determine date of hatching. Length of incubation and duration of hatching period were also documented for each species. Although species gravity was a better predictor of hatching date than egg
Authors
T. W. Custer, G.W. Pendleton, R.W. Roach
Determination of hatching date for eggs of black-crowned night-herons, snowy egrets and great egrets
Floatation of eggs in water and specific gravity of eggs of Black-crowned Night-Herons (Nycticorax nycticorax ), Snowy Egrets (Egretta thula ) and Great Egrets (Casmerodius albus ) were evaluated as methods to determine date of hatching. Although specific gravity was a better predictor of hatching date than egg flotation, both techniques were imprecise. The regression between specific gravity a
Authors
T. W. Custer, G.W. Pendleton, R.W. Roach
Feeding flights of breeding double-crested cormorants at two Wisconsin colonies
Unmarked Double-crested Cormorants (Phalacrocorax auritus ) 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 (maximum 12 km). The mean direction of landing sites differed seasonally for flights from Spider Island, but not
Authors
T. W. Custer, C. Bunck
Effects of mercury, selenium, and organochlorine contaminants on reproduction of Forster's terns and black skimmers nesting in a contaminated Texas bay
Mean mercury (0.40 μg/g), and geometric mean DDE (1.6 μg/g) and polychlorinated biphenyl (PCB) (2.3 μg/g) concentrations in Forster's tern (Sterna forsteri) eggs from Lavaca Bay were higher than those in tern eggs from a reference area in San Antonio Bay, but residues were not correlated with hatching success. Nest success was similar between bays. Selenium levels in Lavaca Bay tern eggs (0.71 μg/
Authors
Kirke A. King, Thomas W. Custer, J. S. Quinn
The occurrence of chlorostyrenes in egrets and herons collected in Galveston Bay
No abstract available.
Authors
C.P. Rice, T. W. Custer
Herons and egrets as proposed indicators of estuarine contamination in the United States
The National Contaminant Biomonitoring Program of the U.S. Fish and Wildlife Service Includes the sampling of freshwater fish, starlings, and duck wings. In order to include an estuarine component, herons and egrets are being evaluated. Organochlorine concentrations were measured In eggs and chicks of Snowy Egrets Egretta thula, Great Egrets Casmerodius albus, and Black-crowned Night-Herons Nyctic
Authors
T. W. Custer, Barnett A. Rattner, H. M. Ohlendorf, M. J. Melancon
Science and Products
Filter Total Items: 185
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
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
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
Redhead duck behavior on lower Laguna Madre and adjacent ponds of southern Texas
Behavior of redheads (Aythya americana) during winter was studied on the hypersaline lower Laguna Madre and adjacent freshwater to brackish water ponds of southern Texas. On Laguna Madre, feeding (46%) and sleeping (37%) were the most common behaviors. Redheads fed more during early morning (64%) than during the rest of the day (40%); feeding activity was negatively correlated with temperature. Re
Authors
C. A. Mitchell, T. W. Custer, P.J. Zwank
Cytochrome P450 responses and PCB congeners in pipping heron embryos from Virginia, the Great Lakes and San Francisco Bay
Pipping black-crowned night-heron (Nvcticorax nvcticorax) embryos were collected from undisturbed (Chincoteague National Wildlife Refuge VA; CNWR) and industrialized (Cat Island, Green Bay WI and San Francisco Bay, CA; SFB) locations. Hepatic monooxygenases (AHH, EROD, BROD, ECOD) were induced up to 100-fold, and were correlated (r=0.50 to 0.72) with total PCB burdens (N =61 embryos). A subset of
Authors
Barnett A. Rattner, M. J. Melancon, T. W. Custer, D.E. Tillett, Bruce R. Woodin, John J. Stegeman
Determination of hatching date for eggs of black-crowned night-herons, snowy egrets and great egrets
Flotation of eggs in water and specific gravity of eggs of Black-crowned Night-Herons (Nycticorax nycticorax), Snowy Egrets (Egretta thula) and Great Egrets (Casmerodius albus) were evaluated as methods to determine date of hatching. Length of incubation and duration of hatching period were also documented for each species. Although species gravity was a better predictor of hatching date than egg
Authors
T. W. Custer, G.W. Pendleton, R.W. Roach
Determination of hatching date for eggs of black-crowned night-herons, snowy egrets and great egrets
Floatation of eggs in water and specific gravity of eggs of Black-crowned Night-Herons (Nycticorax nycticorax ), Snowy Egrets (Egretta thula ) and Great Egrets (Casmerodius albus ) were evaluated as methods to determine date of hatching. Although specific gravity was a better predictor of hatching date than egg flotation, both techniques were imprecise. The regression between specific gravity a
Authors
T. W. Custer, G.W. Pendleton, R.W. Roach
Feeding flights of breeding double-crested cormorants at two Wisconsin colonies
Unmarked Double-crested Cormorants (Phalacrocorax auritus ) 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 (maximum 12 km). The mean direction of landing sites differed seasonally for flights from Spider Island, but not
Authors
T. W. Custer, C. Bunck
Effects of mercury, selenium, and organochlorine contaminants on reproduction of Forster's terns and black skimmers nesting in a contaminated Texas bay
Mean mercury (0.40 μg/g), and geometric mean DDE (1.6 μg/g) and polychlorinated biphenyl (PCB) (2.3 μg/g) concentrations in Forster's tern (Sterna forsteri) eggs from Lavaca Bay were higher than those in tern eggs from a reference area in San Antonio Bay, but residues were not correlated with hatching success. Nest success was similar between bays. Selenium levels in Lavaca Bay tern eggs (0.71 μg/
Authors
Kirke A. King, Thomas W. Custer, J. S. Quinn
The occurrence of chlorostyrenes in egrets and herons collected in Galveston Bay
No abstract available.
Authors
C.P. Rice, T. W. Custer
Herons and egrets as proposed indicators of estuarine contamination in the United States
The National Contaminant Biomonitoring Program of the U.S. Fish and Wildlife Service Includes the sampling of freshwater fish, starlings, and duck wings. In order to include an estuarine component, herons and egrets are being evaluated. Organochlorine concentrations were measured In eggs and chicks of Snowy Egrets Egretta thula, Great Egrets Casmerodius albus, and Black-crowned Night-Herons Nyctic
Authors
T. W. Custer, Barnett A. Rattner, H. M. Ohlendorf, M. J. Melancon