Geology Reports⌕ Search

Geology topics

K. L. Stromborg

Publications and source records attributed to K. L. Stromborg.

24 records · Page 2Linked to original sources
USGS1987

Distribution and effects of acidic deposition on wildlife and ecosystems

Acidic deposition occurs over most of the United States and the deposition patterns and theoretical vulnerabilities of aquatic ecosystems to chemical changes can be delineated, but few data exist on concomitant biological effects. Hypothetical direct effects are limited primarily to toxicity of various heavy metals mobilized at reduced pH. Results of studies in Scandinavia suggest that aluminum interferes with avian reproduction near acidified lakes. Some amphibian populations located on acid-vulnerable substrates may be adversely affected by reduced pH in the vernal pools used for egg laying and larval growth. Indirect effects on populations are difficult to detect because few historical data exist for wildlife populations and trophic relationships in vulnerable areas. Current research in the U.S.A. focuses on measuring habitat characteristics, food availability, and avian use of vulnerable wetland habitats. Results of Scandinavian studies suggest that some species of waterfowl may prefer acidified, I fish-free habitats because invertebrates essential for meeting nutritional requirements are more easily obtained in the absence of competition from fish. However, avian species dependent on fish would be absent from these habitats. Alteration of either the vegetative structure or primary productivity of wetlands might indirectly affect avian populations by causing decreased invertebrate productivity and consequent food limitations for birds.

Book chapter↗
USGS1986

Reproduction of bobwhites fed different dietary concentrations of an organophosphate insecticide, methamidophos

Pairs of first-year breeding bobwhites were fed constant or variable concentrations of methamidophos for 15 days, or a control diet in a pair-fed design in which they were matched by body weights to pairs in the constant group. Treatments for the constant group were 5.0, 7.8, 12.3, 19.2, and 30.0 ppm for 5 pairs at each concentration. The number of pairs per concentration and peak concentrations for the variable pairs were identical to the constant dosages. Concentrations for the variable group were increased by a factor of four during two 3-day periods in order to reach the peak concentrations on days 7–9 after which they were decreased by 18% every 3 days to correspond to an environmental half-time of 10.5 days. Food consumption, egg production, hatchability of eggs under artificial incubation, and survival of hatched chicks for 2 weeks were recorded for each pair during 15-day treatment and 21-day posttreatment periods. Mortality was high in the highest constant dosage (2/10) and the associated pair-fed groups (3/10). Food consumption and egg production rates were negatively dose-related during the treatment period in the constant and variable groups. The laying rate of pair-fed hens was reduced to the same extent as in the constant group. Reproductive inhibition was not permanent and pairs resumed laying after a dose-related recovery interval. No dose-related effects on hatchability or chick survival were detected. Furthermore, there was no evidence of a pesticide effect on reproduction in addition to that exerted through pesticide-induced anorexia.

Archives of Environmental Contamination and Toxico↗
USGS1986

Reproductive toxicity of monocrotophos to bobwhite quail

Pairs of 1st-year breeding bobwhites were fed constant or decreasing concentrations of monocrotophos for 15 days. In addition, a control diet was used in a pair-fed group matched with the pairs in the constant group. Dietary concentrations for the constant group were logarithmically spaced at .100, .178, .316, .562, 1.000 ppm of actual insecticide and also at 0 ppm (control) for five pairs at each concentration. The beginning concentrations for the decreasing pairs were identical to the constant group but regularly decreased to reach 25% of the starting concentrations by Day 13. Food consumption, egg production, hatchability of eggs under artificial incubation, and survival of hatched chicks for 2 weeks were recorded pairwise during 15-day treatment and 14-day posttreatment periods. Mortality was high at the greatest constant concentration and in the associated pair-fed group. Food consumption and egg production rates were negatively dose-related during the treatment period in the constant and decreasing groups. The laying rate of pair-fed hens was reduced to the same extent as in the constant group. Reproductive inhibition was not permanent, and pairs resumed laying after a dose-related recovery interval. No dose-related effects on hatchability or chick survival were detected. There was no evidence of a pesticide effect on reproduction other than that exerted through pesticide-induced anorexia.

Poultry Science↗
USGS1982

Modern pesticides and bobwhite populations

Bobwhite ( Colinus virginianus ) are frequently used as test animals for wildlife tests of pesticides. The organophosphate and carbamate pesticides that have replaced the organochlorines have many desirable properties, but they span a wide range of acute toxicities and some of them affe,ct survival, reproduction, food consumption, behavior, and nervous system enzymes in laboratory tests. Applying these laboratory findings to the field requires assumptions about the severity of exposure in the field. Direct field measurements show that birds may be exposed to significant amounts of these pesticides or even more toxic degradation products under some conditions. Adverse population effects may also result from depression of insect populations during the seasons when bobwhites rely on insects for food.

Book chapter↗
USGS1981

Reproductive tests of diazinon on bobwhite quail

Diazinon was fed at sublethal levels to reproductively active bobwhite (Colinus virginianus). Thirty pairs were given constant concentrations (0, 35. 50, 72, 104, or 150 ppm) for 3 weeks (Constant group). Another 30 pairs (Pair-fed group) were matched to these by body weights and were fed the amounts of untreated food consumed by corresponding Constant pairs to evaluate the effect of food deprivation. To mimic environmental degradation, a group of 30 pairs (Decreasing group) was initially given diazinon at the same concentrations as the Constant group; the concentration was decreased geometrically every 3 days to yield a 50 percent reduction in 15 days. Following 3 weeks of exposure to the experimental diets, pairs were maintained for an additional 3 weeks on untreated food to measure the birds' recovery. Food consumption, egg production, and hatchability were recorded for each pair. Individually hatched chicks were banded and kept for 2 weeks to monitor their survival. Food consumption was negatively dose-related above 35 ppm in the Constant and Decreasing groups. The only reproductive parameter affected was egg production. Production declined as the dose was increased above 35 ppm in the Constant and Decreasing groups. Egg laying was reduced more in the Constant than in the Decreasing pairs. The egg-laying rate of the Constant and Pair-fed groups differed; this difference was reflected by a threshold corresponding to 72 ppm in the Pair-fed group as opposed to 35 ppm in the Constant group. Residual effects of prior treatment on food consumption and egg production were observed in the Constant and Pair-fed pairs during the posttreatment period, but the Decreasing pairs were not influenced by prior treatment. The magnitude of effects related to the dose was not as great during the posttreatment period as during the treatment period and represented the recovery from diazinon effects over the span of the posttreatment period. The schedule of doses for the Decreasing group ameliorated the deleterious effects of diazinon, whereas the dosing schedule for the Constant group yielded a small overestimation of hazard to wildlife.

Book chapter↗