Roy L. Kirkpatrick

Effects of Tannins on Digestion and Detoxification Activity in Gray Squirrels (Sciurus carolinensis)

Acorn tannins may affect food preferences and foraging strategies of squirrels through effects on acorn palatability and digestibility and squirrel physiology. Captive eastern gray squirrels (Sciurus carolinensis) were fed 100% red oak (Quercus rubra) or white oak (Quercus alba) acorn diets to determine effects on intake, digestion, and detoxification activity. Red oak acorns had higher phenol and tannin levels, which may explain the lower dry matter intakes and apparent protein digestibilities and the higher glucuronidation activities observed in squirrels. Although the white oak acorn diet had lower apparent protein digestibilities than the reference diet, it did not suppress dry matter intake for a prolonged period or stimulate glucuronidation. Negative physiological effects of a 100% red oak acorn diet suggest gray squirrels may require other foods to dilute tannin intake and provide additional nutrients. To distinguish the roles of different tannin types in the observed effects of acorn diets on squirrels, squirrels were fed rat chow containing no tannins, 4% or 8% tannic acid (hydrolyzable tannin), or 3% or 6% quebracho (condensed tannin). Apparent protein digestibilities were reduced by tannic acid and quebracho diets. Only the 8% tannic acid diet tended to increase glucuronidation. Specific effects of tannins may largely depend on tannin type, composition, and source and on other nutritional and physiological factors.

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-

Effect of PCB ingestion on sleeping times, organ weights, food consumption, serum corticosterone and survival of albino mice

SummaryThe physiological effects of feeding Aroclor 1254 to mature male white mice at dietary levels of 62.5, 250, and 1000 ppm for 2 weeks are reported. Pentobarbital-induced sleeping time and food consumption were reduced and liver weight was increased in the 250 ppm and 1000 ppm groups. Serum corticosterone was elevated at all levels of PCB treatment; whereas, only exposure to 1000 ppm resulted in heavier adrenal glands. Weights of the testes, preputials and vesicular glands were not significantly affected by PCB ingestion.

Time and energy budgets of American black ducks in winter

We used scan sampling techniques to quantify behavior and energy expenditure of American black ducks (Anas rubripes) at Chincoteague National Wildlife Refuge (NWR), Virginia, during the winters of 1985-86 and 1986-87. Time, tide, and habitat influenced black duck behaviors; therefore, diurnal time budgets were constructed by distributing scans over a time-tide matrix within refuge pool, saltmarsh, and tidal-water habitats. Black ducks observed during the day fed least and rested most when in refuge pools, and fed most and rested least when in tidal waters. Estimated daily energy expenditure (DEE) of American black ducks wintering at Chincoteague NWR was similar to values reported in Maine at a given temperature. Although DEE of undisturbed and disturbed flocks were similar, black ducks curtailed feeding and increased time spent in alert and locomotion behaviors in response to disturbance. We suggest that human disturbance of wintering black ducks impairs their physiological condition, thereby reducing winter survival and/or nutrient reserves carried to the breeding grounds. J. WILDL. MANAGE. 53(2):401-410 The decline in populations of American black ducks over the past 3 decades (Steiner 1984) has prompted behavioral research of wintering black ducks. Albright et al. (1983) investigated behavioral responses of wintering black ducks in Maine to temperature, wind chill, and availability of ice-free foraging habitat. Black ducks rested more and fed less with decreasing temperature and increasing ice, even as total DEE increased due to the demands of thermoregulation. Albright et al. (1983) suggested that black ducks in northern wintering areas experience extreme food shortages and that there was evidence of a physiological set-point below which it is more advantageous to rely on energy reserves than to expend energy searching for food. Hickey and Titman (1983) employed scan sampling to study black ducks wintering on Prince Edward Island; ducks fed less and rested more with increased wind chill and tide level. More information is needed to determine the amount of time black ducks spend in various habitats and to measure nocturnal activity (Hickey and Titman 1983). Brodsky and Weatherhead (1985a,b) demonstrated that local food availability can determine black duck behavioral responses to low temperatures in Canada. Brodsky and Weatherhead (1984) also studied the posturing of black ducks while resting and roosting as a mechanism for reducing thermoregulatory costs. They suggested that the management of energy expenditure is as much a consideration as management of energy intake by black ducks. We used the time-budget approach to quantify behavior and energy expenditure of black ducks wintering on, and in the vicinity of, Chincoteague NWR, Virginia. Objectives were to estimate time and energy expenditure within different habitats, identify environmental factors that influence behavioral response, and contrast black duck allocation of time and energy resources in tidal Virginia with results of studies conducted at higher latitudes. We thank M. R. Vaughan and D. R. Stauffer for suggestions and criticisms during the study and D. W. Howerter for field assistance. This study was supported by the U.S. Fish and Wildlife Service and the Department of Fisheries and Wildlife Sciences, Virginia Polytechnic Institute and State University.

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.

Dietary and Seasonal Influences on Nutritional Indices of Adult Male White-Tailed Deer

Nutritional and seasonal influences on physiological indices of nutritional status were determined in a 1-year experiment with 10 male white-tailed deer (Odocoileus virginianus). The deer were placed on ad libitum or 0.75 ad libitum diets and sampled every 28 days. Voluntary feed intake decreased in October. Body weights peaked in October, reached their lowest level in April, and were greater for ad libitumthan restricted-fed deer. Hemoglobin concentration, packed cell volume, and mean corpuscular hemoglobin content (MCHC) varied monthly; only MCHC was significantly lower in restrictedthan in ad libitum-fed deer. Interactions between study months and diets were observed for blood urea nitrogen and urinary urea nitrogen/creatinine ratios. Significant seasonal variation was observed for serum cholesterol, regardless of level of feeding. Ketone-body concentrations in serum were greater for ad libitumthan restricted-fed deer during the last 4 months of the study. J. WILDL. MANAGE. 45(4):926-936 The use of physiological indices of nutritional status in wild cervids has received much attention in wildlife science. However, before these nutritional indices can be reliably and accurately applied in the field, controlled experiments must be conducted to identify and minimize environmental influences that may lead to alterations in physiological characteristics. Uncontrolled observations may lead an investigator to erroneous conclusions. Kirkpatrick et al. (1975) and Seal et al. (1978a) examined nutritional indices of white-tailed deer fawns under controlled conditions. However, Kirkpatrick et al. (1975) examined only blood urea nitrogen (BUN), and Seal et al. (1978a) conducted their experiment for only 10 weeks. Long-term experiments, similar to that of Bahnak et al. (1979), permit the determination of seasonal variations in physiological indices and thus provide additional valuable information. The objective of our experiment was to identify variations in nutritional indices of adult m le white-tailed deer in response to season and a 25% dietary restriction in a 1-year study. This study was supported in part by a grant from the Pratt Animal Nutrition Foundation at Virginia Polytechnic Institute and State University. Technical assistance was provided by D. Gibson, T. Jones, W. Morehead, J. Dickinson, and H. Warren. U. S. Seal provided assistance in developing the nonesterified fatty acid procedure.

Foods, nutrition, and condition of ruffed grouse in southwestern Virginia

in annual hunter-reported flushing rates led the Virginia Commission of Game and Inland Fisheries to initiate this research investigating potential mechanisms and management implications. The objective of this study was to determine seasonal changes in nutrition and body condition of ruffed grouse in Virginia. Body fat, body weight, and cecal length were monitored as condition indices in birds col-

Habitat use and movements of American black ducks in winter

We determined habitat use and movement patterns of 22 female American black ducks (Anas rubripes) wintering at Chincoteague National Wildlife Refuge (NWR), Virginia, with radio telemetry and aerial survey techniques during 15 December 1985-28 February 1986. Proportional use of saltmarsh, impoundment, and natural pool habitats was greater (P 1. Habitat use was affected by the day-night cycle and a tide-ice interaction. J. WILDL. MANAGE. 53(2):390-400 American black duck populations wintering along the Atlantic Flyway have declined almost 50% since 1954 (Steiner 1984). Excessive harvest (Geis et al. 1971, Blandin 1982, Grandy 1983), acid rain (Hansen 1987), and hybridization with mallards (Anas platyrhynchos) (Heusmann 1974, Ankney et al. 1987) have been suggested as factors responsible for this decline. Others believe that loss and degradation of wintering habitat may be affecting black duck populations, although the evidence is somewhat con-

Ruffed Grouse (Bonasa umbellus) Brood Microhabitat Selection in the Southern Appalachians

Abstract Brood cover is a critical component of ruffed grouse habitat during a period when chick mortality may be high. We compared microhabitat characteristics at ruffed grouse (Bonasa umbellus) brood locations with random locations to determine characteristics selected by females with broods in the Appalachian region of Virginia and West Virginia. Females with broods used forested sites with a well-developed overstory canopy (>70%). These sites had a higher abundance of arthropods in the first 3 wk after hatch (P = 0.02), taller ground cover (P < 0.1) and higher percent ground cover (P < 0.1) in the first 6 wk after hatch than random sites. Total woody stem densities were not different (P > 0.1) between brood and random sites as has been found in several studies from more northern sites. Most management prescriptions for ruffed grouse brood habitat are based on increasing hardwood stem densities; our results suggest alternative habitat management techniques that promote ground cover, such as prescribed burning and forest stand thinning, may be more appropriate in the southern Appalachian region.

Polychlorinated biphenyls and nutritional restriction: their effects and interactions on endocrine and reproductive characteristics of male white mice.

Abstract Aroclor 1254, a polychlorinated biphenyl (PCB), was fed to adult male white mice in an ad libitum diet at levels of 50 and 200 ppm and in a restricted diet (50% of the amount consumed ad libitum ) at levels of 100 and 400 ppm to compare effects and possible interactions of PCB ingestion and feed restriction on select endocrine and reproductive characteristics and barbiturate-induced sleeping times. The mice were maintained on the two nutritional levels for 30 days, whereas the PCB was incorporated into the diets during the final 15 days only. PCB ingestion significantly increased paired adrenal gland weights, liver weights, and plasma corticoid concentrations. In addition, PCB-fed mice exhibited reduced testicular spermatozoa concentrations and pentobarbital-induced sleeping times. PCB feeding did not affect final body weights or the weights of the reproductive organs. Feed restriction reduced the weights of the seminal vesicles, preputial glands, testes, and final body weights. Feed restriction increased adrenal weights, pentobarbital-induced sleeping time, and plasma corticoid concentrations. Liver weights and testicular spermatozoa concentrations were not affected by feed restriction. The PCB-associated reduction in sleeping time was greater in feed-restricted mice than in mice allowed food ad libitum . The effect on plasma corticoid concentrations was greatly intensified in mice subjected to PCBs and feed restriction simultaneously as compared to mice subjected to feed restriction or PCB feeding separately.