Geology topics

G. H. Heinz

Publications and source records attributed to G. H. Heinz.

75 records · Page 5Linked to original sources

USGS1976

Methylmercury: Second-year feeding effects on mallard reproduction and duckling behavior

For 2 consecutive years mallard ( Anas platyrhynchos ) hens were fed a control diet or a diet that contained 0.5 or 3 ppm mercury as methylmercury (about 0.1 and 0.6 ppm mercury on the basis of a natural succulent diet). During the fifth egg-collection period, levels of mercury in eggs of hens fed 0.5 and 3 ppm mercury averaged 0.79 and 5.46 ppm, respectively; on a dry-weight basis, the concentration of mercury in eggs was 4.88 times as great as that in the feed of ducks fed 0.5 ppm mercury and 5.64 times as great for ducks fed 3 ppm mercury. There were no significant differences in egg production or hatching success among controls and groups fed mercury. Ducklings from hens fed 3 ppm mercury were less likely to survive to 1 week of age than were controls or ducklings from parents fed 0.5 ppm mercury. There were no significant differences in approach behavior among the offspring of controls and groups fed mercury. In avoidance behavior, ducklings whose parents were fed 3 ppm mercury were hyper-responsive compared with controls and ducklings from parents fed 0.5 ppm mercury.

Journal of Wildlife Management↗

USGS1976

Methylmercury: Second generation reproductive and behavioral effects of mallard ducks

Mallard ducks ( Anas platyrhynchos ) whose parents were fed a diet containing 0.5 ppm mercury (equal to about 0.1 ppm mercury in a natural diet) also were fed a diet containing 0.5 ppm mercury beginning at 9 days of age and continuing through their reproductive season. Mercury in the eggs of treated hens averaged 0.86 ppm. Hens fed 0.5 ppm mercury made less efficient use of feed and laid a greater percentage of eggs outside nestboxes compared with controls. Hens fed mercury also produced fewer 1-week-old ducklings than did controls. There were no significant differences between controls and ducklings from parents fed 0.5 ppm mercury in approach responses to tape-recorded maternal calls, in avoidance of a frightening stimulus, or in open-field behavior. Ducklings from parents fed 0.5 pprn mercury did not grow as fast as did control ducklings.

Journal of Wildlife Management↗

USGS1974

The effect of sublethal dosages of five pesticides and a polychlorinated biphenyl on the avoidance response of coturnix quail chicks

Coturnix quail (Coturnix coturnix) chicks were given sublethal amounts of chlordane, dieldrin, endrin, DDE, Ceresan M, or Aroclor 1254 (a polychlorinated biphenyl) in their feed, beginning at seven days of age, and their avoidance response to a moving silhouette was measured daily for fourteen days. The birds were on dosage for eight days, and on untreated feed for six days immediately thereafter. Group avoidance response was significantly suppressed (P from 0?01 to <0?001) by chlordane, dieldrin, endrin, Ceresan M, and Aroclor 1254. No effect of DDE on the birds' behaviour could be detected. The behaviour of the endrin-treated birds returned to normal after two days on untreated feed. The data indicated partial recovery for birds treated with dieldrin and chlordane, but none for those Ceresan M, or Aroclor 1254. The percentage of controls responding to the silhouette dropped from an average of 84 for the first four days to 70 on the sixth day; then it increased until the end of the test when it was almost 80. This apparently aberrant behaviour of healthy birds is tentatively attributed to a daily decrease in the discrepancy between the moving silhouette and the birds' schema for the silhouette, followed by maturation of the central nervous system, beginning at about the fourteenth day of age. We believe this maturation effected revival of interest and hence a heightened reaction to the stimulus.

Environmental Pollution↗