Chemical analyses of deer bladder urine and urine collected from snow

Urinalysis has provided a new avenue for identification and study of nutritional indices in white-tailed deer (Odocoileus virginianus). Initial studies examined urea nitrogen (Warren et al. 1981, 1982; Waid and Warren 1984; DelGiudice et al. 1987a), electrolytes, and hydroxyproline; all showed potential as indicators of nutritional condition (DelGiudice et al. 1987a, 1988). During early undernutrition and starvation, deer conserve urea nitrogen, sodium, and potassium by renal tubular reabsorption; and urinary excretion of these characteristics decreases progressively (DelGiudice et al. 1987a, 1988; DelGiudice and Seal 1988). Similarly, decreases in urinary hydroxyproline have been associated with declining nutrition (Whitehead 1965, McCullagh 1969). As nutritional deprivation is prolonged, catabolism of endogenous protein, including bone collagen, increases, thereby dramatically increasing urinary urea nitrogen and hydroxyproline, as well as sodium, potassium, and calcium (DelGiudice et al. 1987a, DelGiudice and Seal 1988). The practicality of collecting such physiological data for research and management purposes is often limited. It is expensive, timeconsuming, and often difficult to capture and immobilize free-ranging animals to acquire data on physiological condition (DelGiudice et al. 1987b).