Advancing a 24-Hour Time-Activity Budget for Wintering Atlantic Flyway Canada Geese: Consideration of Nocturnal Behavior
University of Delaware
Canada geese (Branta canadensis), both resident and migratory, utilize many areas in New Jersey as wintering and breeding grounds. Biologists and wildlife managers are interested in establishing time-activity budgets for geese and other waterfowl to help determine carrying capacities, daily energy needs, and other ecological information. In order to accurately create these budgets, it is important to observe behaviors over a complete 24 hr period, a task not easily achievable due to constraints of nighttime observation. Therefore, nocturnal activity is often dismissed. My objectives in this study were to 1) examine whether various Canada goose behaviors differed between the four time periods of a day (morning crepuscular, diurnal, evening crepuscular, and nocturnal) and 2) explore the effects of environmental variables and human hunting disturbance on goose behavior comparatively between diurnal and nocturnal periods. The behavioral observations for this study took place in coastal habitats in New Jersey. Observations included 7 behaviors (feeding, resting, comfort, swimming, alert, flying, and walking), 6 environmental variables (temperature, wind speed, cloud cover, tide, ice coverage and precipitation), and whether or not sites fell within hunting areas and open hunting season. I analyzed behavioral observations across time periods using multiple analysis of variance (MANOVA, α ≤ 0.05). I further analyzed individual behavioral differences between observation periods using univariate analysis of variance (ANOVA, α ≤ 0.05) with Tukey’s post-hoc pair-wise comparisons. To analyze environmental variables and hunting, I used backwards stepwise regression to find the best-fitting model. Feeding, resting, and swimming were the most common behaviors. I found that behavior proportions differed across observation periods (MANOVA, F21, 2777 = 6.32, P < 0.01). Further univariate ANOVA with Tukey’s post-hoc pair-wise comparisons indicated individual behavioral differences existed between observation periods. Additionally, I found that environmental variables and hunting lead to differences in the 3 most common behaviors (feeding, resting, and swimming) between diurnal and nocturnal periods. The results of this study show that Canada geese are far more active nocturnally than previously assumed. Further, it showed that environmental variables and human hunting disturbance have an effect on behavior and can cause birds to be more or less active during certain time periods. This information can be valuable for future wildlife researchers and managers in considering time-energy budgets for Canada geese and acknowledging that nocturnal behavior should be incorporated into 24 hr budgets.