Meeting Abstract
A common anthropogenic influence on wildlife is the use of supplemental bird feeders. Dependent on abundance and natural food availability, this supplemental food source may influence survival and productivity. We experimentally manipulated supplemental food availability in a wild population of Eastern Bluebirds, Sialia sialis, to examine the influence of bird feeding on nesting success, especially when supplemental feeding is inconsistent. Adult and nestling bluebirds were assigned to one of three groups. In the first group, birds received mealworms throughout breeding. In the second group, birds received mealworms from nest completion until nestlings hatched. Birds in the third group received no supplementation but were disturbed at the same frequency. Nestling growth and nest success were then calculated. Finally to determine if differences in habitat quality contributed to the effect of food supplementation on nest success, data on invertebrate abundance were collected on a subset of territories. Nestling mass, tarsus, and wing chord length were not significantly affected by experimental treatment. Further, clutch size, hatching success, brood size, and fledging success were not significantly affected by treatment. Invertebrate abundance and richness were similar between years, across grass heights, as well as across nest box trails. Invertebrate abundance and richness were not correlated with nesting success metrics and did not statistically influence nesting success. Supplemental food availability may only have significant effects on nest success in years with low environmental food availability. Although we did not find direct benefits of supplemental feeding for bluebirds, bird feeding can be beneficial to the community, scientists and wildlife through engagement of the public in science.
