Grantee: Daniel Hanley

Institution: George Mason University, United States

Grant amount: $60,000

Grant type: Challenge grants

Focal species: Prothonotary warbler (Protonotaria citrea)

Conservation status: Least concern

Disciplines: Ornithology, animal behavior, population ecology

Research location: United States

Project summary

The juvenile stage is where welfare conditions are likely the most variable and impactful on an individual’s growth and behavior. Unfortunately, methods for measuring, assessing, and comparing welfare have been a barrier to our understanding of juvenile welfare. Like other aspects of animal life history, welfare will vary between individuals and also over the lives of animals in an age-specific fashion. Thus, metrics such as welfare expectancy can inform us of the welfare that an organism is likely to experience, similar to how life expectancy can provide an estimate on how much longer an organism may live. 

This study examines welfare in free-living juvenile songbirds to establish standardized field and analytical procedures necessary to obtain age-specific animal welfare estimates. Prothonotary warblers are an ideal model system for studying age-specific welfare because they have well-defined life stages (i.e., egg, nestling, fledgling, subadult, adult), face unique environmental risks (e.g., drought and flooding), and have variable survival. Furthermore, members of this species nest within cavities, which affords a degree of standardization and control necessary for an initial investigation of welfare metrics. Such initial investigations are crucial to estimate age-specific welfare on wild juvenile animals, to determine how they deviate from population-level welfare estimates, and to extend these methods and metrics to other systems.

Why we funded this project

We funded this project because it sought to explicitly quantify welfare across life stages, using multiple physiological, behavioral, and environmental/demographic indicators. Knowing how (and ideally why) average welfare differs over the course of life in a population could have important implications for interventions to improve their welfare (e.g., fertility control). We were also impressed with this PI because he engages numerous students in their lab and is relatively early in his own career, potentially allowing for pivot to focus more on wild animal welfare. He also demonstrated a good understanding of Wild Animal Initiative’s research on the welfare expectancy framework and sought to put the concepts into practice. That sort of theory-to-practice pipeline would represent a significant step for welfare biology as a research field.

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