Geology topics
M. A. Haegele
Publications and source records attributed to M. A. Haegele.
Acute oral and percutaneous toxicity of pesticides to mallards: Correlations with mammalian toxicity data
Acute oral (po) and 24-hr percutaneous (perc) LD50 values for 21 common pesticides (19 anticholinesterases, of which 18 were organophosphates, and one was a carbamate; one was an organochlorine central nervous system stimulant; and one was an organonitrogen pneumotoxicant) were determined in mallards ( Anas platyrhynchos ). Three of the pesticides tested were more toxic percutaneously than orally. An index to the percutaneous hazard of a pesticide, the dermal toxicity index (DTI = po LD50/perc LD50 × 100), was also calculated for each pesticide. These toxicity values in mallards were compared with toxicity data for rats from the literature. Significant positive correlations were found between log po and log percutaneous LD50 values in mallards ( r = 0.65, p < 0.01), between log po LD50 values in mallards and in rats ( r = 0.71, p < 0.01), and between log DTI values in mallards and in rats ( r = 0.52, p < 0.05). Percutaneous toxicity values were not significantly correlated between mallards and rats ( r = 0.36, p > 0.10). Variations in percutaneous methodologies are discussed with reference to interspecies variation in toxicity values. It is recommended that a mammalian DTI value approaching 30 be used as a guideline for the initiation of percutaneous toxicity studies in birds, when the po LD50 and/or projected percutaneous LD50 are less than expected field exposure levels.
Reduction in courtship behavior induced by DDE in male ringed turtle doves
The effects of p,p?-DDE on the intensity of male Ringed Turtle Doves? courtship behavior were determined for dietary levels of 10 ppm and 50 ppm (dry weight). Pairs of doves were placed in cages for 12.5 min on 5 consecutive days for behavioral observation before dietary treatment and for periods 31-35 and 5963 days after initiation of the treated diet. Total amount of time spent displaying courtship behavior and bow-coo frequency were analyzed through video tape recording..... The 50.ppm diet caused a reduction in total courtship activity time and in bow-coo frequency for both posttreatment observation periods. The 10-ppm diet did not affect bow-coo frequency and total activity time at 31-35 days but did cause a significant reduction in courtship behavior during the 59-63.day observation period. The DDE residues found in the male Ringed Turtle Doves showing reduced courtship behavior were lower than residues found in many species of birds that have shown reproductive failures in the wild.
Effects of dietary mercury and lead on eggshell thickness in mallards
No abstract available.
Eggshell thinning and residues in mallards one year after DDE exposure
A group of 16 mallard hens ( Anas platyrhynchos ), that had been given feed containing 40 ppm of p,p' -DDE for 96 days, laid eggs with shells averaging about 15%–20% thinner than those of ten control birds during and up to 42 days after treatment. In eight of the treated birds killed at that time, whole-body DDE residues averaged 33.1 ppm (wet weight). The other eight treated birds and ten controls were kept through the winter with no additional DDE exposure and penned separately five days for individual egg collection about three weeks after laying began in spring. At that time (nearly 11 months after DDE feeding had stopped), the treated birds laid eggs with shells averaging 7.4% thinner than control eggshells (significant at P≤0.05) and their whole-body DDE residues averaged 9.6 ppm (wet weight). Variations in eggshell thickness and DDE residues were considerable among treated birds. However, regression analysis showed moderate negative correlations (r=−0.51 to −0.62) between eggshell thickness and DDE residues in whole bodies and eggs, and strong positive correlations (r=0.73 and 0.91) between DDE residues in whole bodies and in eggs.
DDE: Interference with extra-renal salt excretion in the mallard
The effects of DDE on the function of the salt gland, the main route of sodium chloride excretion in marine birds, were investigated in mature mallards, Anas platyrhynchos, maintained on either fresh water or 1 percent salt water and given 0, 10, 100, or 1000 ppm DDE in the diet (12 birds per level). The rate of sodium chloride excretion by the salt gland following injections of concentrated salt solutions was not reduced (from that of controls) in DDE -treated birds maintained on salt water, but was significantly reduced in DDE -treated birds not previously given salt.
DDE effects on reproduction of ring doves
Reproductive performance was measured for 126 days in twelve pairs of ring doves ( Streptopelia risoria ) fed a diet containing 40 ppm of p,p'-DDE and in twelve other pairs given untreated food. The DDE-treated doves took an average of 2 1 2 "> 2 1/2 times longer to renest than controls, produced 13·5% fewer eggs/clutch, had 10% thinner eggs, and experienced twice as great mortality of young; all these differences were statistically significant. Hatchability was also lower but not significantly so. Control birds nested forty-nine times during the study, laying two eggs in each clutch. DDE-treated birds nested only thirty-three times, laying an average of 1·7 eggs/clutch. The combined effects of DDE on reproduction resulted in only ten young being successfully raised by DDE-treated pairs versus thirty-five being raised by controls.
Comparative acute oral toxicity of pesticides to six species of birds
Acute oral LD50 values were determined for 16 common pesticides on mallard ducks ( Anas platyrhynchos ), ring-necked pheasants ( Phasianus colchicus ), chukar partridges ( Alectoris graeca ), coturnix quail ( Coturnix coturnix japonica ), common pigeons ( Columba livia ), and house sparrows ( Passer domesticus ). Analyses of the data revealed that (1) the average sensitivity of any one species to the 16 pesticides did not differ statistically from that of any other species, and (2) at the same time, the species varied widely in their sensitivity to any given compound. The average range of the LD50 values for single chemicals in the 6 species was nearly 10-fold. With differences of this magnitude, it is recommended that extrapolation of toxicity data from one species to another be avoided.