Experimentally Induced Flight Costs Do Not Lead To Increased Reliance On Supplemental Food In Winter By A Small Songbird

Each year hundreds of millions of people intentionally feed wild animals throughout the world. For decades, concerns have persisted regarding the potential for intentional feeding to promote dependency on human-supplemented food, particularly during energetically demanding periods of the annual cycle. In this study, we evaluated whether individuals subjected to experimentally increased flight costs responded by increasing their use of supplemental feeders in a wild, free-ranging population of the black-capped chickadee Poecile atricapillus. We subjected 67 RFID-tagged chickadees to one of three handicapping treatments (heavy feather-clipping, light feather-clipping or unclipped controls) and then evaluated feeder use of each individual relative to their pre-treatment level. Contrary to predictions, we found that chickadees in both feather-clipping treatments exhibited a short-term reduction in feeder use, returning to feeding levels of unmanipulated controls within approximately two weeks of treatment implementation. Similarly, experimental feather-clipping treatments had little influence on changes in the number of feeders used or on the timing of feeder visits across the daily cycle, relative to controls. Our results indicate that experimental handicapping of chickadees led to relatively minor and transient changes in the use of supplemental food with no evidence that handicapped individuals increased their reliance on supplemental bird feeders. These findings suggest that recreational bird feeding is unlikely to lead to feeder dependency in small songbirds during winter, although additional research on this topic should be a priority given the global footprint of intentional feeding of wildlife.