Thomas Custer (Former Employee)
Science and Products
Filter Total Items: 167
Brain cholinesterase activity of nestling great egrets snowy egrets and black-crowned night-herons Brain cholinesterase activity of nestling great egrets snowy egrets and black-crowned night-herons
Inhibition of brain cholinesterase (ChE) activity in birds is often used to diagnose exposure or death from organophosphorus or carbamate pesticides. Brain ChE activity in the young of altricial species increases with age; however, this relationship has only been demonstrated in the European starling (Sturnus vulgaris). Brain ChE activity of nestling great egrets (Casmerodius albus)...
Authors
T. W. Custer, H. M. Ohlendorf
Organochlorines and mercury in eggs of coastal terns and herons in California, USA Organochlorines and mercury in eggs of coastal terns and herons in California, USA
In San Franciso Bay, California, USA, concentrations of DDE and mercury in eggs differed among Caspian Tern, Forster's Tern, Black-crowned Night-Heron, and Snowy Egret in 1982. Geometric mean DDE concentrations were higher (P 0.05) in Caspian Tern eggs (6.93 ppm, wet weight) than in eggs of other species (1.92-2.84 ppm). Mean mercury concentrations were significantly greater in Caspian...
Authors
H. M. Ohlendorf, T. W. Custer, Roy W. Lowe, M. Rigney, E. Cromartie
Nesting by pomarine jaegers near Barrow, Alaska, 1971 Nesting by pomarine jaegers near Barrow, Alaska, 1971
An estimated 5.7 pairs of pomarine jaegers km -2 (14.8 mi -2) nested near Barrow, Alaska, in 1971. Hatching success of 67 eggs (34 nests) was 57%. Fledging success of 44 nestlings (26 nests) was 32%. An estimated 0.4 young survived to 25 d of age per nesting attempt. Low fledging success is explained by an abrupt decline in lemming abundance.
Authors
Thomas W. Custer, Frank A. Pitelka
Exposure to insecticides of brushland wildlife within the Lower Rio Grande Valley, Texas, USA Exposure to insecticides of brushland wildlife within the Lower Rio Grande Valley, Texas, USA
Brushland wildlife within the Lower Rio Grande Valley of south Texas were studied following applications of eleven insecticides to nearby sugarcane or cotton fields. During the study no wildlife were found dead. Mean brain acetylcholinesterase (AChE) activity of great-tailed grackles (Quiscalus mexicanus) and mourning doves (Zenaida macroura) was significantly lower than controls...
Authors
T. W. Custer, C. A. Mitchell
Organochlorine contaminants and reproductive success of black skimmers in south Texas, 1984 Organochlorine contaminants and reproductive success of black skimmers in south Texas, 1984
Ninety-four Black Skimmer (Rhynchops niger) nests on a dredged-material island colony near Laguna Vista, Texas, were fenced and monitored in 1984 from early incubation until 21 d after the last egg hatched. The daily probability of success was greater during the nestling (99.7%/d/nest) period than during the incubation (98.5%) or hatching (98.5%) periods. By contrast, the success of eggs...
Authors
Thomas W. Custer, Christine A. Mitchell
Reproductive success and heavy metal contamination in Rhode Island common terns Reproductive success and heavy metal contamination in Rhode Island common terns
Common tern cIutch size, reproductive success and growth of young recorded from an abandoned barge on the Providence River, an area of heavy metal contamination, were equal to, or greater than, .from less contaminated areas. Concentrations of copper and zinc were higher in livers of nestling terns from the Providence River than from other, less contaminated, areas. However...
Authors
T. W. Custer, J. C. Franson, John F. Moore, J.E. Myers
Science and Products
Filter Total Items: 167
Brain cholinesterase activity of nestling great egrets snowy egrets and black-crowned night-herons Brain cholinesterase activity of nestling great egrets snowy egrets and black-crowned night-herons
Inhibition of brain cholinesterase (ChE) activity in birds is often used to diagnose exposure or death from organophosphorus or carbamate pesticides. Brain ChE activity in the young of altricial species increases with age; however, this relationship has only been demonstrated in the European starling (Sturnus vulgaris). Brain ChE activity of nestling great egrets (Casmerodius albus)...
Authors
T. W. Custer, H. M. Ohlendorf
Organochlorines and mercury in eggs of coastal terns and herons in California, USA Organochlorines and mercury in eggs of coastal terns and herons in California, USA
In San Franciso Bay, California, USA, concentrations of DDE and mercury in eggs differed among Caspian Tern, Forster's Tern, Black-crowned Night-Heron, and Snowy Egret in 1982. Geometric mean DDE concentrations were higher (P 0.05) in Caspian Tern eggs (6.93 ppm, wet weight) than in eggs of other species (1.92-2.84 ppm). Mean mercury concentrations were significantly greater in Caspian...
Authors
H. M. Ohlendorf, T. W. Custer, Roy W. Lowe, M. Rigney, E. Cromartie
Nesting by pomarine jaegers near Barrow, Alaska, 1971 Nesting by pomarine jaegers near Barrow, Alaska, 1971
An estimated 5.7 pairs of pomarine jaegers km -2 (14.8 mi -2) nested near Barrow, Alaska, in 1971. Hatching success of 67 eggs (34 nests) was 57%. Fledging success of 44 nestlings (26 nests) was 32%. An estimated 0.4 young survived to 25 d of age per nesting attempt. Low fledging success is explained by an abrupt decline in lemming abundance.
Authors
Thomas W. Custer, Frank A. Pitelka
Exposure to insecticides of brushland wildlife within the Lower Rio Grande Valley, Texas, USA Exposure to insecticides of brushland wildlife within the Lower Rio Grande Valley, Texas, USA
Brushland wildlife within the Lower Rio Grande Valley of south Texas were studied following applications of eleven insecticides to nearby sugarcane or cotton fields. During the study no wildlife were found dead. Mean brain acetylcholinesterase (AChE) activity of great-tailed grackles (Quiscalus mexicanus) and mourning doves (Zenaida macroura) was significantly lower than controls...
Authors
T. W. Custer, C. A. Mitchell
Organochlorine contaminants and reproductive success of black skimmers in south Texas, 1984 Organochlorine contaminants and reproductive success of black skimmers in south Texas, 1984
Ninety-four Black Skimmer (Rhynchops niger) nests on a dredged-material island colony near Laguna Vista, Texas, were fenced and monitored in 1984 from early incubation until 21 d after the last egg hatched. The daily probability of success was greater during the nestling (99.7%/d/nest) period than during the incubation (98.5%) or hatching (98.5%) periods. By contrast, the success of eggs...
Authors
Thomas W. Custer, Christine A. Mitchell
Reproductive success and heavy metal contamination in Rhode Island common terns Reproductive success and heavy metal contamination in Rhode Island common terns
Common tern cIutch size, reproductive success and growth of young recorded from an abandoned barge on the Providence River, an area of heavy metal contamination, were equal to, or greater than, .from less contaminated areas. Concentrations of copper and zinc were higher in livers of nestling terns from the Providence River than from other, less contaminated, areas. However...
Authors
T. W. Custer, J. C. Franson, John F. Moore, J.E. Myers