Patrick F. Scanlon

Reproductive and Physiological Effects of Environmental Contaminants in Fish-Eating Birds of the Great Lakes: A Review of Historical Trends

During the 1950s and 1960s, reproductive failures and population declines were observed in fish-eating birds such as gulls, terns, cormorants, herons, and eagles in the Great Lakes. DDE-induced eggshell thinning contributed to these declines, but other factors such as embryo toxicity also were implicated. With reduced releases of many pollutants, reproduction recovered in some species. However, biomonitoring during the 1980s and 1990s indicates continuing effects at highly contaminated sites. Improved analytical techniques and bioassays have allowed the assessment of the total dioxin-like toxicity of complex mixtures of organochlorines (TCDD-equivalents). Developmental defects such as embryo mortality, deformities, and edema have been associated with dioxin-like PCBs in several avian species. Improved biochemical techniques have allowed the measurement of biomarkers that detect physiological alterations associated with contaminants. Specific biomarkers studied in Great Lakes birds include cytochrome P-450 monooxygenases, highly carboxylated porphyrins, thyroxine, vitamin A, and immune function. Reproductive and physiological alterations are associated with population-level effects in Caspian terns and bald eagles that feed on highly contaminated fish. Biomonitoring using biomarkers and population-level measures in fish-eating birds will continue to be important for assessing the effects of contaminants on the Great Lakes ecosystem.

Heavy metals in tissues of waterfowl from the Chesapeake Bay, USA

Concentrations of cadmium, lead, copper and zinc were measured in 774 livers, 266 kidneys and 271 ulnar bones from 15 species of ducks obtained from the Chesapeake Bay region. A major purpose of this study was to elucidate relationships between food habits and tissue accumulations of heavy metals in Chesapeake Bay waterfowl. Liver and kidney concentrations of cadmium were highest among two carnivorous seaduck species, Clangula hyemalis and Melanitta deglandi. In contrast, lead concentrations in tissues were generally highest in largely herbivorous species, such as Anas platyrhynchos, Anas rubripes and Anas strepera. Spent shot may be an important source for tissue burdens of lead in these ducks. No marked trends were observed between food habits and tissue concentrations of the nutrient elements, copper and zinc.

Effects of acute lead ingestion and diet on antibody and T-cell-mediated immunity in Japanese quail

This study investigated the interacting effects of acute lead exposure and different diets on antibody and T-cell-mediated immunity in Japanese quail (Coturnix coturnix). Nine quail (nine week old males) were assigned randomly to each group in a factorial experiment with four treatments and two diets. The treatments were 1) a positive control group fed 20 μg/g corticosterone, 2) a negative control group given no lead or corticosterone, 3) a low-lead group, and 4) a high-lead group. The low and high lead groups received 100 and 400 μg/ml lead as lead acetate in drinking water for 7 d. The two diets were poultry feed and ground corn. Control quail fed corn lost 13–14% of initial body mass, but lead-dosed quail fed corn lost 23–24%. All quail fed poultry feed gained body mass. On the corn diet, three high-lead and one low-lead quail died of lead poisoning. Corn increased the percentage of heterophils in white blood cells (P=0.0018) and decreased lymphocytes (P=0.019) and monocytes (P=0.0073). There was marginal evidence that lead increased the heterophil/lymphocyte ratio in corn-fed quail (P=0.064). Corn decreased the T-cell-mediated response to an intradermal injection of phytohemagglutinin (P=0.0001). Corticosterone suppressed this response more than lead. In corn-fed quail, lead suppressed the primary total antibody response to immunization with chukar partridge (Alectoris graeca) erythrocytes (P<0.05). Lead reduced the secondary total antibody and IgG responses in the low lead, corn group (P<0.05). Lead suppressed antibody-mediated immunity only at dosages that also caused clinical lead poisoning.

Energy, Protein, and Seasonal Influences on White-Tailed Deer Fawn Nutritional Indices

Shortand long-term influences of dietary energy and protein on physiological indices of nutritional status were determined in a factorial experiment with 12 male and 12 female captive whitetailed deer (Odocoileus virginianus) fawns. Blood and urine samples were collected after 1, 2, 4, 8, 16, and 32 weeks on experimental diets. Body weights throughout the experiment were greater (P < 0.001) for male than for female fawns. Concentrations of blood urea nitrogen (BUN) and urinary urea/creatinine (U/C) ratios throughout the experiment were greater (P < 0.001) in fawns on high protein diets than in fawns on low protein diets. Blood urea nitrogen concentrations and urinary U/C ratios also were greater (P < 0.01) in fawns on low energy diets than in fawns on high energy diets over the duration of the experiment. A substantial reduction in BUN concentrations was observed after 8 months in those fawns which initially exhibited elevated BUN concentrations. Significant differences were observed among sample periods during the 8-month experiment for hemoglobin, packed cell volume, mean corpuscular hemoglobin content, albumin, BUN, cholesterol, nonesterified fatty acids, total ketone bodies, and urinary U/C ratios. J. WILDL. MANAGE. 46(2):302-312 Physiological indices for assessing nutritional status of populations of wild animals, most notably cervids, have long been the subject of research in wildlife science. Biochemical analyses of blood and urine hold promise as being reliable nutritional indices. However, assessing nutritional status with these methods must necessarily depend on controlled experiments to evaluate their efficiency and accuracy. Several investigators have examined nutritional indices of whitetailed deer under controlled conditions (Kirkpatrick et al. 1975, Seal et al. 1978a, Bahnak et al. 1979). No reports have been found in which differences in nutritional indices according to energy, protein, sex, and duration of dietary exposure were examined in a single experiment. The objective of the present study was to determine the shortand long-term effects of dietary energy and protein on nutritional indices of male and female white-

Effects of chronic lead ingestion on reproductive characteristics of ringed turtle doves Streptopelia risoria and on tissue lead concentrations of adults and their progeny

Ringed turtle doves Streptopelia risoria received 0 or 100 μg ml−1 lead in their drinking water for two weeks prior to pairing and throughout a breeding cycle. Lead treatment did not increase the time required to produce eggs, did not disrupt egg production, and disruptions in fertility of eggs were not detected. Testes weights were lower (p < 0·05) in lead treated birds where spermatozoan numbers tended to be lower. Bone lead was higher (p < 0·05) in doves ingesting lead, and females had more than ten times the bone lead concentrations of males. Lead was transmitted from adults to juveniles via the egg and probably by feeding young with crop milk. Progeny of lead-treated parents had higher (p < 0·05) lead concentrations in bones, livers and primary feathers than progeny of controls. Packed cell volumes and body weight gains of juveniles were not disturbed by lead treatment of parents.

Effects of cadmium ingestion and food restriction on energy metabolism and tissue metal concentrations in mallard ducks (Anas platyrhynchos)

The single and combined effects of cadmium ingestion and food restriction were examined in a 42-day experiment with male, juvenile mallard ducks. A 2 X 3 factorial design was employed consisting of two levels of food supply (ad libitum and 55% of ad libitum intake) and three levels of cadmium in the food (0, 5, or 50 micrograms Cd/g food). Cadmium ingestion alone had no effect on body or tissue weights, liver glycogen, plasma concentrations of glucose, urea, uric acid, nonesterified fatty acids (NEFA), triiodothyronine (T3), thyroxine (T4), or plasma or adrenal concentrations of corticosterone. The food restriction resulted in reduced body weights and reduced weights of livers, kidneys, and testes, increased adrenal weights, reduced liver glycogen, increased plasma NEFA concentrations, reduced plasma T3 and T4 concentrations, and increased adrenal corticosterone concentrations. In combination with the food restriction, cadmium ingestion further reduced plasma T3 concentrations and a similar trend was noted for T4. Additionally, the highest plasma NEFA concentrations and highest plasma and adrenal concentrations of corticosterone were observed in food-restricted ducks receiving the highest level of dietary cadmium. These results suggest the ability of cadmium ingestion to enhance food restriction-induced alterations in energy metabolism at levels of dietary cadmium that are by themselves without apparent effect. Also, cadmium ingestion resulted in increased kidney concentrations of copper and zinc; this effect on kidney zinc concentrations was increased in food-restricted ducks.

Serial changes in metabolic correlates of hibernation in female black bears

Captive female black bears were immobilized and sampled at approximately 10-day intervals from September to March during 2 years (six bears/year) in Virginia. Ten of 12 bears hibernated for an average of 92 days. Rectal temperature declined ( P < 0.001) during hibernation to as low as 34.6°C. Average loss in mass for hibernators was 260 g/day and represented 23.1% of peak body mass. Urea : creatinine ratios differed ( P < 0.01) after hibernation between hibernators and active bears, declining to 7.2 ± 0.3 ( X ± SE ; 84 samples) during hibernation. Serum concentrations of total protein, urea nitrogen, creatinine, and bilirubin also differed ( P < 0.01) between groups after onset of hibernation. Urea : creatinine ratio was a good indicator of the hibernating state, but the sensitivity of serum-urea concentrations to diet suggests careful use of this ratio as a field index of hibernation.

Lead Concentrations in Livers of Maryland Waterfowl with and without Ingested Lead Shot Present in Gizzards

The significance of lead poisoning in waterfowl caused by ingestion of spent lead shot has long been recognized (WETMORE, 1919) as has the adverse impact on waterfowl populations (BELLROSE, 1959). The majority of observations on lead shot ingestion by waterfowl have been with dabbling duck species. Much less work has been done on diving ducks and geese although the problem of lead toxicity in these species has been studied by such as DIETER et ai.(1976) and DIETER (1979) working with canvasback ducks (Aythya valisineria), DANELL et al. (1977) working w~c~ards(~ ferina), tufted ducks (Aythya fuligula) and goldene--~ (-Bucephala clangula~a-6-d--COOK & TRAINER (1966) working with Canada geese (Branta canadensis). Techniques are available for monitoring the presence of ingested lead shot in gizzards of waterfowl such as direct examination of dead birds and fluoroscopic methods for live or dead birds. These are somewhat limited insofar as ingested lead pellets may be eroded relatively rapidly and/ or excreted leaving no direct evidence of recent acute lead ingestion regardless of presence of ingested lead shot. The present report is concerned with comparison of liver lead concentrations in 14 species of waterfowl with and without ingested lead shot present in their gizzards.

Lead Levels in Small Mammals and Selected Invertebrates Associated with Highways of Different Traffic Densities

SummaryLead levels in small mammals were studied in 6 areas — 3 associated with highways of different traffic densities, and 3 control sites in forested areas. Lead levels were also studied in insects from 2 traffic areas and in earthworms from different distances from 2 traffic areas. Lead levels were low in insects ranging from 3.84 μg/g to 3.35 μg/g. Lead levels in earthworms were highest in those recovered closest to highways and from the area with the higher traffic volume. Lead levels in mammals generally was highest in mammals from areas of higher traffic densities. Higher levels of lead were found in shrews than inPeromyscus andMicrotus.

Heavy metals in aquatic plants, clams, and sediments from the Chesapeake Bay, U.S.A. implications for waterfowl

Abstract Dry weight concentrations of cadmium, lead, copper and zinc were measured in clams, submerged aquatic macrophytes and sediments from several locations in the Chesapeake Bay region. Clam species included Macoma balthica, Mya arenaria, and Rangia cuneata; plant taxa included Najas spp., Potamogeton spp., Ruppia maritima, Vallisneria americana, and Zostera marina. Cadmium and lead concentrations were generally greater in whole plants than in soft tissues of clams, while the reverse was true for zinc; no marked trend was observed in copper concentrations. These results suggest that the changes occurring in the food habits of some Chesapeake Bay waterfowl towards increased clam utilization as a result of declining submerged plant abundances is not increasing ingestion of the nonessential metals cadmium and lead. Highest lead, copper and zinc concentrations were observed in sediments from the Patapsco River, which is probably due to the proximity of Baltimore Harbor. Highest cadmium concentrations were observed in sediments in the Port Tobacco River, a tributary of the Potomac River. These observations were generally consistent with high concentrations of the respective metal(s) in biota from these locations. Concentrations of the four metals in sediments were highly correlated to organic matter content.