Pesticide effects on body temperature of torpid/hibernating rodents (Peromyscus leucopus and Spermophilus tridecemlineatus)

Environmental contaminants have been shown in the lab to alter thyroid hormone concentrations. Despite the role these hormones play in the physiological ecology of small mammals, no one has investigated the possible effects of thyroid-disrupting chemicals on mammalian thermal ecology and thermoregulatory ability. Because the energetic impact of such a disruption is likely to be most dramatic during times already energetically stressful, we investigated the effects of two common pesticides (atrazine and lindane) on the use of daily torpor in white-footed mice, and the use of hibernation in 13-lined ground squirrels. Fortunately, we found that these strategies for over-wintering success were not impaired

Arkansas Gray Fox Fur Price-Harvest Model Revisited

Peck and Heidt (1985) proposed a linear model that demonstrated that for gray fox (Urocyon cinereoargenteus) in Arkansas; total fur harvests from 1966-1982 were highly correlated with mean pelt values. Single variable models using linear regression analysis of current season pelt values (CSPV) and previous season pelt values (PSPV) were designed to predict total fur harvests. These models demonstrated high correlations (r =0.93 and 0.89, respectively). In the past 15 years, markets for fur have undergone many perturbations within Arkansas and overseas resulting in great changes in mean pelt prices. In an attempt to evaluate the continued performance of the original model, pelt price and harvest data from 1983-1997 were tested for correlation using linear regression analysis. The results from these tests showed a high correlation. Two specific years (1983 and 1987) were affected strongly by political and economic events. A new model encompassing trapping seasons from 1966 through 1997 was evaluated. Mean pelt value remains a significant predictor of total gray fox fur harvest in Arkansas