Assessing the relationship between garden bird feeding patterns and weather in Vancouver, Canada
Abstract
A recent increase in garden bird feeding by the public has provided birds with a novel food source, impacting ecosystem interactions, ecological niches, and migration of facultative migratory birds. The larger implications of garden bird feeding are not well understood and require further research. This study assesses the relationship between weather and feeding patterns in Vancouver, Canada in order to determine the optimal environmental conditions for studying garden birds in the future. Artificial nectar and seed feeders located in an urban setting were observed for 15 minutes (n=22) in the morning (09:00-11:00) and afternoon (15:00-17:00). Total feeding time and the number of feeding events were recorded, along with data on environmental temperature, wind speed, and brightness. A one-tailed paired t-test revealed a significant difference in nectar and seed feeding times (p=0.002) so data from the two feeders were analyzed separately. A second one-tailed paired t-test revealed insignificant differences between morning and afternoon total seed feeding time (p=0.27), number of seed feeding events (p=0.10), total nectar feeding time (p=0.38), and number of nectar feeding events (p=0.43), so the AM and PM data were combined, plotted, and a regression model was developed. While brightness did not impact feeding patterns, linear regressions showed an inverse relationship between wind and total feeding time or number of feeding events for both seed- and nectarfeeders. A 2nd order polynomial regression showed minimum nectar feeding occurs at 10ºC, while seed-feeding is unaffected by temperature. The study concludes that future analyses on garden birds should occur in less windy weather, below 7ºC or above 12ºC for maximal observations.
