Environmental contaminants in eastern Cooper's hawk eggs
No abstract available.
Connecticut, Maryland, Michigan, Pennsylvania, Wis↗
Geology topics
T. Earl Kaiser
Publications and source records attributed to T. Earl Kaiser.
Temporal accumulation of organochlorine pesticides in shorebirds wintering on the south Texas coast, 1979-80
Organochlorine pesticide residues were determined in 168 shorebirds of three species collected at approximate bimonthly intervals during the fall and winter months of 1979–80 near Port Mansfield on the south Texas coast. The study was conducted to determine if shorebirds wintering on mudflats at the outlets of agricultural drains in Texas accumulated pesticides during this period. The predominant Organochlorine residues detected in shorebirds were DDE, dieldrin, and toxaphene. Ninety-five % of the skinned carcasses analyzed contained detectable levels of DDE, 13% contained dieldrin, and 22% contained toxaphene. DDE significantly increased in all species of shorebirds from October to December, with potentially dangerous levels accumulating in some long-billed dowitchers ( Limnodromus scolopaceus ) and American avocets ( Recurvirostra americana ), but DDE residues seldom exceeded 0.5 ppm in carcasses of western sandpipers ( Calidris mauri ). After about two months on the study area, no further residue increases were documented. The high levels of DDE detected in a large proportion of the dowitchers, and to a lesser extent in the avocets, are near or within the range known to inhibit reproduction in some avian species. This study demonstrates that certain aquatic areas near agricultural lands on the south Texas coast may be potential threats to waterbirds eight years after the use of DDT was banned in the United States.
Texas↗
Clutch size, reproductive success, and organochlorine contaminants in Atlantic coast black-crowned night-herons
In 1979, we gathered clutch-size and reproductive-success data on Black-crowned Night-Herons ( Nycticorax nycticorax ) nesting in three New England and two North Carolina colonies. In 1975, we gathered similar data from one of the New England and one of the North Carolina colonies. Latitudinal differences in clutch initiation were not evident. Mean clutch size was larger in the New England than in the North Carolina colonies. Mean clutch size was smaller in late nests from one New England colony studied in both years and another New England colony studied in 1979; seasonal trends in clutch size for other colonies were not found. In 1979, nest success was greater in two New England colonies than in one North Carolina colony. Within-season differences in nest success occurred but were inconsistent among colonies. In the four instances where statistical comparisons could be made, larger clutches were more successful than smaller ones in two colonies; large and small clutches had similar success in two other colonies. One egg was collected from each of several nests in each colony in 1979 for organochlorine contaminant analysis, and the fate of the remaining eggs was recorded. Concentrations of DDE and PCBs did not differ with clutch size; concentrations of PCBs were lower, however, in eggs laid late in the season. Although the data suggest an effect of DDE on hatching success in the northern more contaminated colonies, the impact of environmental contaminants on overall reproductive success appears to be minimal.
Massachusetts, North Carolina, Rhode Island↗
Organochlorine residues in bats after a forest spraying with DDT
Background levels of DDT and its metabolites (ZDDT) were extremely low or not detected in five species of forest-dwelling bats in northeastern Oregon, i.e., areas not sprayed with DDT in 1974. Other organochlorine pesticides were rarely found and no polychlotinated biphenyls (PCBs) were detected at any time during the study. Four of five species of bats showed significant changes in Z:DDT residues in, their carcasses following the single DDT spray application. Myotis californicus and M. volans showed the highest post-spray carcass residues, 6.90 and 6.21 ppm (wet weight). respectively. Lasionycteris noctivagans and Eptesicus fuscus also showed an increase; however, M. evotis exhibited no significant post-spray change. By 1977 (3 years post-spray), residues declined and only M. californicus and M. volans contained levels that were significantly above those in the nonspray (control) area. We are uncertain if the elevated residue levels resulting from the DDT-spray project adversely affected any of the bats. An attempt to relate bat carcass ZDDT residues to food habits, through analysis of stomach contents, yielded no clear relationships.
Northwest Science↗
Organochlorine pesticide, PCB, and PBB residues and necropsy data for bald eagles from 29 states - 1975-77
During 1975-77, 168 bald eagles ( Haliaeetus leucocephalus ) found moribund or dead in 29 states were analyzed for organochlorine pesticides and polychlorinated biphenyls (PCBs); 32 specimens from 13 states were analyzed for polybrominated biphenyls (PBBs). PCBs were present in 166 bald eagle carcasses and DDE was found in 165. TDE and dieldrin were identified in 137 samples, trans-nonachlor in 118, and oxychlordane in 90. Brains of five eagles contained possible lethal levels of dieldrin, and two eagles possibly died of endrin poisoning. Nine eagle livers, analyzed because of suspected lead poisoning, contained high levels of lead. Twenty percent of the eagles died from shooting, the most common cause of death; this cause of death, however, has declined.
Alaska, California, Colorado, Florida, Georgia, Id↗
Insecticides applied to a nursery colony of little brown bats (Myotis lucifugus): Lethal concentrations in brain tissues
Forty-six Myotis lucifugus were collected in May and June 1974 at a nursery colony in Hillsborough County, New Hampshire, that had been sprayed with DDT and chlordane in August and September 1973. When collected, 27 bats were alive, two were convulsing, and 17 were dead. Brains, carcasses, and milk and masticated insects from stomachs were analyzed for organochlorine insecticides and poly-chlorinated biphenyls (PCB's). Concentrations of chemical residues in brains of surviving bats were compared with those of dead and convulsing bats. These comparisons indicated that DDT was the cause of death. Lethal brain concentrations of DDT in adult females averaged 24.52 parts per million (ppm) and suggested that adult M. lucifugus are approximately twice as sensitive to DDT as are adult laboratory rats and mice. Juvenile bats were about 1.5 times more sensitive than adult bats. Large chemical residues were present in milk. We found a statistically significant relationship between declines in carcass residues in lactating females and uterine regression for six of 10 toxicants. Among juveniles, there were corresponding, significant increases (for nine of 10 toxicants) in carcass levels of residues correlated with increasing age (growth of forearm).
New Hampsire↗
Organochlorine residues and eggshell thinning in anhingas and waders
Residues of organochlorine compounds occur commonly in environmental samples and have been associated with adverse effects in numerous avian species (Cooke 1973; L. F. Stickel 1973; W. H. Stickel 1975; Ohlendorf et al. 1977; H. M. Ohlendorf, R. W. Risebrough, and K. Vermeer, unpublished manuscript). The affected species are usually terminal consumers, generally those feeding on aquatic organisms (primarily fish) or birds. Brown Pelicans ( Pelecanus occidentalis ), Double-crested Cormorants (Phalacrocorax auritus) , and certain herons are among the species that have exhibited shell thinning in some regions (see Ohlendorf et al. 1977 for review). In 1972, we began a study to determine: (1) geographic differences in the occurrence of environmental pollutants in Anhingas ( Anhinga anhinga ) and waders in the eastern United States; (2) differences in environmental pollutant levels among those species nesting at the same localities; and (3) whether eggshell thickness had changed since the widespread use of organochlorine pesticides began in the mid-1940's. The wader species included in our study were: Great Blue Heron ( Ardea herodias ), Green Heron ( Butorides virescens ), Little Blue Heron ( Florida caerulea ), Cattle Egret ( Bubulcus ibis ), Reddish Egret ( Dichromanassa rufescens ), Great Egret ( Casmerodius albus ), Snowy Egret ( Egretta thula ), Louisiana Heron ( Hydranassa tricolor ), Black-crowned Night Heron ( Nycticorax nycticorax ), Yellow-crowned Night Heron ( Nyctanassa violacea ), Least Bittern ( Ixobrychus exilis ), American Bittern ( Botaurus lentiginosus ), Wood Stork ( Mycteria americana ), Glossy Ibis ( Plegadis falcinellus ), White Ibis ( Eudocimus albus ), and Roseate Spoonbill ( Ajaia ajaja ).
Conference Paper↗