Geology topics
Publications and source records attributed to M. Anne Ross McLane.
Mallard drakes accumulated mercury rapidly from dietary dosage of methylmercury dicyandiamide and eliminated it slowly, retaining approximately one half at the end of 84 days; no measurable loss occurred between the end of the 7th and 56th days, but loss resumed concurrently with new feather growth, and continued through the 112th day, the close of the study.
Wings from woodcock ( Philohela minor ) were first monitored for organochlorine pesticides and polychlorinated biphenyls (PCBs) in the eastern U.S. in 1971. Regional differences in these compounds were clearly demonstrated and baseline residue levels were obtained for later comparisons. An expanded sampling of wings in 1972 revealed that residues in wings of adult woodcock may differ significantly from those in immatures, and that residues of several important agricultural insecticides and PCBs had declined significantly. More extensive sampling was undertaken in 1975 to determine if changes in residue levels had taken place in the intervening years. PCBs, mirex, and heptachlor epoxide increased significantly between 1972 and 1975 in adult woodcock wings. In immature woodcock wings mirex, dieldrin, and PCBs increased significantly between 1972 and 1975, but DDT residues decreased significantly.
The relative importance of two organochlorine pesticides in the recent reproductive failure of raptors was investigated. Captive barn owls were fed 3.0 ppm DDE and 0.5 ppm dieldrin; doses were given separately and in combination for two years. Breeding success was followed from the laying of eggs through natural incubation and rearing of young. DDE was associated with significant eggshell thinning, egg breakage, embryo mortality, and reduced production per pair. Dieldrin alone was associated with slight but significant eggshell thinning, but not with reduction of breeding success. Ecological implications of the results are discussed; it is suggested that DDE had a much more severe effect on reproduction in wild raptors than dieldrin, which contributed to their decline primarily through adult mortality.
Aroclor® 1248 was fed to captive screech owls ( Otus asio ) at the rate of three ppm in the diet to determine if reproductive effects such as fewer eggs per clutch, lower hatchability, malformation of the chicks, or higher mortality rates of chicks would appear in this raptorial species as they did in chickens. There were no effects on eggshell thickness, number of eggs laid, young hatched, and young fledged from feeding a low level of Aroclor® 1248 to captive screech owls. The polychlorinated biphenyl (PCB) residues found in the eggs of the dosed birds ranged from 3.9 ppm to 17.8 ppm. Background PCB residues in the diet of all experimental birds ranged from non-detected to 0.62 ppm.
Pesticide residues in wings of adult woodcock (Philohela minor) were used to monitor regional differences in a 1970-71 survey of DDT, DDE, TDE, dieldrin, mirex, and PCBs in Maine, New Hampshire, New York, New Jersey, Pennsylvania, North Carolina, South Carolina, Georgia, Lousiana, Michigan, and Wisconsin. In 1971-72, wings were sampled again to compare levels of organochlorine insecticide residues with those of the previous survey and to delineate differences in residue values between adult and immature woodcock. Three additional states, Massachusetts, Minnesota, and Vermont, and one additional organochlorine insecticide, heptachlor epoxide, were included in the second survey. Residue levels in the 1971-72 wings showed the same pattern as that observed in 1970-71: organochlorine insecticide residues were highest in wings collected in the southern states and in New Jersey; residues were lowest in samplings taken in the northern and midwestern states. Residues of DDT, TDE, and dieldrin in the 1971-72 wings were slightly lower than those found in 1970-71. DDE, PCB, and mirex residues were significantly lower (P<0.05, P<0.01, and P<0.01, respectively) in 1971-72. Wings of immature woodcock in Louisiana had significantly lower (P <0.05) mirex residues than did adult wings.
During Late 1970 and early 1971, 229 woodcock (Philohela minor) were collected from 23 Eastern and Midwestern States. Analyses for chlorinated hydrocarbons and mercury in these migratory birds showed generally low levels which are not considered dangerous to human consumers. In this survey, Louisiana woodcock had lower residues of heptachlor epoxide and DDE than those tested in a 1965 survey. PCB levels, however, may have increased. Mirex levels were greatest in Mississipi and Louisiana woodcock. Pooling of birds and averaging of individually analyzed birds did not provide equivalent estimates of equivalent residues; pool values tended to be larger and more variable. Levels of six chlorinated hydrocarbons and mercury were negatively correlated with the latitude of the collection site. However, this relationship seemed weakest for PCB's. Among eight chemical residues, PCB levels were most often correlated with levels of the other seven. Levels of chlorinated hydrocarbons in wings were correlated with levels in breast muscle and in carcass; however, mean levels of certain residues differed significantly among wing, muscle, and carcass even when compared on a lipid basis.
A survey of organochlorine residues in woodcock wings was undertaken to determine whether these wings are suitable for showing regional differences in residues and to obtain a baseline in 1970-71 for later comparisons. Woodcock wings were obtained from the annual hunter's wing survey. Samples came from eight States (Louisiana, Maine, Michigan, New Hampshire, New Jersey, New York, Pennsylvania, and Wisconsin) and one tri-State area (North Carolina, South Carolina, and Georgia). Wings from the tri-State area contained significantly higher (P<0.01) concentrations of DDT (including DDT, DDD, and DDE) than those from other States. Concentrations of polychlorinated biphenyls (PCB's) also were significantly higher (P<0.05) in samples from these three States. Wings from Louisiana and the tri-State area had significantly higher (P<0.01) concentrations of dieldrin than wings from the other States, and those from Louisiana had significantly higher (P < 0.01) concentrations of mirex than those from other States. (Residues are on lipid base) The compounds detected and the ranges of residue means for all sampling areas were as follows: Total DDT (5.89--65.15 ppm); DDT (0.34 m--14.93 ppm); DDE (4.66--47.47 ppm); DDD (0.11--3.44 ppm); mirex (0.76--16.93 ppm); dieldrin (0.09--3.06 ppm); and PCB's (4.27--8.63 ppm). Woodcock wings appear to be suitable for determining regional differences in organochlorine residues in this species.
No abstract available.