SEASONAL VARIATION AND EFFECTS OF WINTER TICKS (DERMACENTOR ALBIPICTUS) ON CONSUMPTION OF FOOD BY CAPTIVE MOOSE (ALCES ALCES) CALVES

Abstract

Effects of season and level of winter tick (Dermacentor albipictus) infestation on food intake by moose (Alces alces) were evaluated using 4 heavily infested calves (41,000 larval ticks), 4 moderately infested claves (21,000 larval ticks) and 4 uninfested calves. Food intake for all moose averaged 0.03 kg feed/kg moose/day. Mean daily food intake declined from approximately 0.05 kg feed/kg moose/day in early October, reaching low levels in late February (0.02 kg feed/kg moose/day). Food intake increased during late March and early April. These trends in consumption of food were consistent with trends observed for other northern cervids. The occurrence of ticks (level of infestation) showed no effect on consumption of food (P = 0.2419). Similarly, there was no evidence that tick activity (inactive vs. active growth phases) affected food intake (P = 0.8289). This experiment does not support the hypothesis that infestation with winter ticks influences food intake in captive moose. However, the possibility of D. albipictus affecting consumption of food by moose under other experimental conditions such as higher levels of infestation or under natural conditions with possible increased time and energy spent acquiring food should not be discounted.