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U.S. Seal

Publications and source records attributed to U.S. Seal.

At least 19 recordsLinked to original sources
USGS2005

Conservation genetics of the endangered Isle Royale gray wolf

The small group of wolves on Isle Royale has been studied for over three decades as a model of the relationship between large carnivores and their prey. During the last ten years the population declined from 50 individuals to as few as 12 individuals. The causes of this decline may be food shortages, disease, or reduced genetic variability. We address the issues of genetic variability and relationships of Isle Royale wolves using allozyme electrophoresis, mtDNA restriction-site analysis, and multilocus hypervariable minisatellite DNA analysis (genetic fingerprinting). Our results indicate that approximately 50% of the allozyme heterozygosity has been lost in the island population, a decline similar to that expected if no immigration had occurred from the mainland. The genetic fingerprinting data indicate that the seven sampled Isle Royale wolves are as similar as captive populations of siblings. Surprisingly, the Isle Royale wolves have an mDNA genotype that is very rare on the mainland, being found in only one of 144 mainland wolves ThFF suggests that the remaining Isle Royale wolves areprobably derived from a single female founder.

Michigan↗
USGS1994

Nutritional restriction and acid-base balance in white-tailed deer

We examined the effect of progressive nutritional restriction on acid-base balance in seven captive, adult white-tailed deer ( Odocoileus virginianus ) from 4 February to 5 May 1988 in north central Minnesota (USA). Metabolic acidosis was indicated by low mean blood pH (7.25 to 7.33) in deer throughout the study. Mean urinary pH values declined ( P = 0.020) from a mean (±SE) baseline of 8.3 ± 0.1 to 6.7 ± 0.3 as restriction progressed. Acidemia and aciduria were associated with significant variations in mean blood CO 2 ( P = 0.006) and pO 2 ( P = 0.032), serum potassium ( P = 0.004) concentrations, and with a significant ( P = 0.104) handling date × group interaction in urinary potassium : creatinine values. Mean bicarbonate : carbonic acid ratios were consistently below 20:1 during nutritional restriction. Mean packed cell volume increased ( P = 0.019) and serum total protein decreased ( P = 0.001); thus there was evidence for progressive dehydration and net protein catabolism, respectively. Blood pCO 2 , serum sodium, and urinary sodium : creatinine were stable throughout the study. We propose that acidosis and aciduria are metabolic complications associated with nutritional restriction of white-tailed deer.

Journal of Wildlife Diseases↗
USGS1992

Seasonal patterns of weight, hematology, and serum characteristics of free-ranging female white-tailed deer in Minnesota

Weights, hematology, and serum profIles of white-tailed does in the central Superior National Forest of northeastern Minnesota were examined year-around to determine seasonal patterns of nutritional condition and metabolism. Deer were initially captured by Clover trap or rocket net. Between 15 February 1989 and 23 January 1990, we recaptured 12 adult (> 1.5 years) female deer 1-9 times each (a total of 59 recaptures) using a radio-controlled capture collar. Monthly weights of deer exhibited a cyclic seasonal pattern. Mean weight declined 22 % from February to an annual minimum during May, then steadily increased 45 % to a maximum in October. Seasonal patterns were most evident for hemoglobin concentration, red blood cells, packed cell volume, serum total protein, urea nitrogen, creatinine, the urea N to creatinine ratio, triiodothyronine, cortisol, and potassium. Wide seasonal variations of these characteristics were indicative of shifts in the deer's metabolic physiology. Although seasonal metabolic shifts are partially attributable to an endogenous rhythm, the intensity of, their expression was most likely affected by nutritional changes and concomitant alterations of body condition. Annual changes in seasonal trends of blood characteristics may be useful in investigating nutritional effects of specific environmental and demographic factors. We compare our findings with those reported for deer on ranges farther south.

Minnesota↗
USGS1991

Gray wolf density and its association with weights and hematology of pups from 1970 to 1988

We examined weights and hematologic profiles of gray wolf ( Canis lupus ) pups and the associated wolf density in the east-central Superior National Forest of northeastern Minnesota (USA) during 1970 to 1988. We collected weight and hematologic data from 117 pups (57 females, 60 males) during 1 September to 22 November each year. The wolf density (wolves/800 km 2 ) trend was divided into three phases: high (72 ± 7), 1970 to 1975; medium (44 ± 2), 1976 to 1983; and low (27 ± 2), 1984 to 1988. Wolf numbers declined ( P = 0.0001) 39 and 63% from 1970 to 1975 to 1976 to 1983 and from 1970 to 1975 to 1984 to 1988, respectively. Weight was similar between male and female pups and did not vary as wolf density changed. Mean hemoglobin ( P = 0.04), red ( P = 0.0001) and white blood cells ( P = 0.002), mean corpuscular volume, mean corpuscular hemoglobin concentration and mean corpuscular hemoglobin ( P = 0.0001) did differ among the multi-annual phases of changing wolf density. Weight and hematologic data also were compared to values from captive wolf pups. The high, but declining wolf density was associated with macrocytic, normochromic anemia in wolf pups, whereas the lowest density coincided with a hypochromic anemia. Although hematologic values show promise for assessing wolf pup condition and wolf population status, they must be used cautiously until data are available from other populations.

Minnesota↗
USGS1991

Weights and hematology of wild black bears during hibernation

We compared weights and hematological profiles of adult (>3-yr-old) female black bears ( Ursus americanus ) during hibernation (after 8 January). We handled 28 bears one to four times (total of 47) over 4 yr of varying mast and berry production. Mean weight of lactating bears was greater ( P < 0.0001) than that of non-lactating females. White blood cells ( P < 0.05) and mean corpuscular volume ( P = 0.005) also differed between lactating and non-lactating bears. Hemoglobin ( P = 0.006) and mean corpuscular hemoglobin concentration ( P = 0.02) varied among years; values were lowest during 1975, following decreased precipitation and the occurrence of a second year of mast and berry crop shortages in a three-year period. Significant ( P < 0.05) interaction between reproductive status (lactating versus non-lactating) and study year for hemoglobin, red blood cells, and packed cell volume, and increased mean corpuscular volume, suggested a greater nutritional challenge for lactating females compared to non-lactating females during the 1975 denning season. Our data suggest that hematological characteristics of denning bears may be more sensitive than weights as indicators of annual changes in nutritional status; however, other influential factors, in addition to mast and berry crop production, remain to be examined.

Journal of Wildlife Diseases↗
USGS1990

The influence of social and endocrine factors on urine-marking by captive wolves (Canis lupus)

Although serum hormones varied seasonally in all adult animals, only dominant male and female wolves urine-marked. Serum testosterone and urine-marking rates, which increased during the fall/winter breeding season, were positively correlated in both male and female dominant wolves. Estradiol, which increased in conjunction with proestrus and estrus, was not correlated with female urine-marking. These findings suggest that hormonal influence on urine-marking in the wolf is modulated by social factors and contrast with those for both domestic dogs and coyotes, two other members of the genus Canis.

Hormones and Behavior↗
USGS1988

Response of urinary hydroxyproline to dietary protein and fasting in white-tailed deer

The effects of dietary protein, fasting, and refeeding on urinary hydroxyproline of nine captive female white-tailed deer ( Odocoileus virginianus ) were examined from 23 February to 3 May 1984 in northern Minnesota. In the fasted group, mean hydroxyproline: creatinine (OHP:C) was greater ( P < 0.05) at week 4 compared to baseline at week 0. Between fasted deer and deer fed high protein-high energy (HPHE) and low protein-high energy (LPHE) diets, no difference in OHP:C ratios was detected during the initial 4 wk of the study. Urinary OHP:C ratios were significantly ( P < 0.05) greater in the fasted group during refeeding, concomitant with greater feed consumption and weight gain. There was also a significant ( P < 0.02) time effect in the fasted-refed group; OHP:C ratios increased during these two phases of the study. There was no difference between the HPHE and LPHE fed deer in renal OHP excretion. However, mean OHP:C ratios in yearlings (16.8 ± 2.2) were greater ( P <0.001) than in the adults (7.5 ± 1.2) of those groups, indicating a higher collagen turnover rate. Urinary OHP:C shows potential as an indicator of growth and starvation, and the data presented may serve as reference values.

Journal of Wildlife Diseases↗
USGS1987

Cardiovascular and behavioral responses of gray wolves to ketamine-xylazine immobilization and antagonism by yohimbine

Adult wolves ( Canis lupus ) were immobilized with 6.6 mg/kg ketamine hydrochloride (KET) and 2.2 mg/kg xylazine hydrochloride (XYL) administered intramuscularly. Induction time was 4.6 ± 0.3 min ( x̄ ± SE). Immobilization resulted in significant bradycardia and hypertension ( P < 0.05). Twenty min after induction, the wolves were given 0.05–0.60 mg/kg yohimbine hydrochloride (YOH). Yohimbine given intravenously produced dose-related increases in heart rate (HR) with doses >0.15 mg/kg resulting in extreme tachycardia (>300 bpm). All doses of YOH caused a temporary decrease in mean arterial blood pressure (MABP) with some individual animals manifesting profound hypotension (<30 torr) at doses >0.15 mg/kg. Increasing the dose of YOH above 0.15 mg/kg did not significantly decrease either arousal or ambulation times. Administering YOH at 40 or 60 min after induction resulted in decreased arousal and ambulation times. Stimulation by weighing and taking repeated blood samples during anesthesia did not shorten arousal times. We recommend that wolves immobilized with XYL-KET be antagonized with doses of YOH <0.15 mg/kg.

Journal of Wildlife Diseases↗