2017 | Birdfeeding Dynamics

FACULTY SEED GRANT | Global Change Center

Coupled social and ecological dynamics of backyard bird feeding

INVESTIGATORS:

Dr. Dana Hawley, Biological Sciences
Ashley Dayer, Fish and Wildlife Conservation

Backyard feeding of birds is arguably one of the most widespread and global forms of direct human-wildlife interaction. However, despite the enormous and growing popularity of bird-feeding, the ecological impacts of this unprecedented spatial scale of wildlife provisioning remain largely unstudied. Moreover, although psychological benefits of bird-feeding have been documented, we lack a clear understanding of how the extent of songbird provisioning by humans is influenced by the perceived or observed ecological impacts of provisioning. Because many of the potential ecological impacts of bird-feeding, whether “positive“ (i.e., increases in bird abundance) or “negative” (i.e., increases in disease or predation), are directly visible to backyard bird-watchers, there is likely to be strong coupling between human decisions about feeding birds and the perceived or observed effects of provisioning on songbird populations. Here we leverage the enormous popularity of bird-feeding to examine both the social and natural dynamics of bird-feeding, and the way in which human and natural systems are coupled. In particular, we ask:

What factors motivate human food-provisioning behavior, and is provisioning behavior coupled with bird abundance or the prevalence of natural enemies (disease and predators)?
How do the abundance of birds and their natural enemies change as a function of supplemental food provisioning by humans?

To address these questions, we will combine online social survey responses from birdwatchers, analysis of large-scale ecological data collected by citizen scientists watching backyard feeders, and intensive local field studies that manipulate provisioning and examine ecological impacts. We focus our work on a common and charismatic backyard songbird — the house finch — that has been subject to a very visible disease (“pink-eye”) since the mid-1990s. Bird feeders have been hypothesized to drive outbreaks of this disease, which caused up to 60% declines in house finch population size. However, empirical data linking bird feeders to disease dynamics remain rare. Because backyard birdwatchers were instrumental in documenting the spread of pink-eye in house finches, this system is ideal for asking how observations of sick birds may feedback to influence provisioning of birds, either in positive or negative ways.

Seed grant funds will support two types of preliminary data collection that merge our interdisciplinary expertise in social (Dayer) and biological sciences (Hawley).