Density-Dependent Welfare in Wild Bird Social Networks: Linking resource distributions with disease dynamics
Grantee: Josh Firth
Institution: University of Oxford, United Kingdom
Grant amount: $99,466
Grant type: Challenge grants
Focal species: Great tits (Parus major), blue tits (Cyanistes caeruleus)
Conservation status: Least concern
Disciplines: Animal behavior, community ecology, infectious disease, population ecology, ornithology, bio/eco-informatics, ecological modeling, animal welfare science
Research location: United Kingdom
Project summary
This project seeks to understand the interplay among various potential density-dependent drivers of positive and negative welfare impacts to determine net welfare related to aggregation (increased density) in wild birds (two species of tit). Infectious disease transfer and increased competition, both likely to reduce welfare, are expected to be directly related to population density. However, population density also covaries with processes that are potentially beneficial to welfare, such as congregation around areas that provide high nutrition, various social benefits, opportunities for increased cooperation, or access to social information. The study will use long-term datasets to empirically determine how the relationship between population density and individual welfare is shaped by infectious disease, including the density-dependent relationship with disease spread. Additionally, using historical data, the project will test how population density, mediated by social contact, environment, and disease, determines individuals’ body condition and mortality risk. Based on the results of this observational phase of the study, the investigators will then manipulate density experimentally, to test model outputs and determine potential causal links.
Why we funded this project
This project brings two unique advantages. First, the investigators have access to a population that has been subject to intensive monitoring for decades, meaning that much of the relevant ecological context is known and there is historical data to analyze retrospectively. Secondly, in part due to this long-term monitoring, the birds are tagged and observed at feeding stations equipped with RFID tags/readers that allow for experimental manipulation of the density and identity of birds feeding at particular stations. By empirically testing density-dependent models of welfare, the project could provide an increased understanding of the interplay among population density, infectious disease, and various social and environmental characteristics, and in doing so, identify drivers of welfare in wild birds.
