Physiological and behavioral effects of nicarbazin on feral urban pigeons (Columba livia)
Grantee: Jessica X. Wright-Lichter
Institution: Tufts University, United States
Grant amount: $30,000
Grant type: Small grants
Focal species: Urban pigeon (Columba livia domestica)
Conservation status: Least concern
Disciplines: Physiology, ornithology, animal welfare science
Research location: United States
Project summary
Nicarbazin (NCZ) is an oral contraceptive that has been shown to be effective in feral urban pigeons (Columba livia). However, although it is EPA-approved and widely marketed, no published studies examine the impact of prolonged exposure to NCZ on the pigeons beyond the contraceptive effect. This is concerning because evidence from agricultural use of the compound (where it was originally developed as an antiparasitic drug) suggests that NCZ exposure may limit the ability of birds to cope with high heat.
To study the impact of NCZ treatment on pigeon welfare, especially as a function of heat exposure, feral pigeons will be treated with NCZ for three weeks before being exposed to increased ambient temperature for four hours to assess their physiological and behavioral responses compared to a control group. This project will use changes in levels of the hormone corticosterone as a physiological proxy for welfare in exposed pigeons. The researchers will also look for behavioral correlations by measuring the onset and frequency of heat-mediating behaviors (e.g., panting, wing-spreading). The behavioral (and plausibly welfare-relevant) effects of NCZ treatment alone will also be assessed by quantifying impacts on affiliative and aggressive behaviors, social status, and access to feed at bait sites.
Why we funded this project
We funded this project because we see wildlife fertility control — particularly applied to urban pigeons — as a highly promising near-term intervention. We are especially interested in indirect welfare effects of fertility control (e.g.,on juvenile welfare and survival), but we have also been concerned by the lack of research on direct welfare impacts. This study will focus on direct welfare impacts while also providing some of the first data on NCZ’s effects on pigeon social dynamics, which are likely to be very important determinants of overall welfare. These data could then be used to guide the application of NCZ contraceptives (e.g., their seasonal timing) to maximize pigeon well-being while successfully controlling urban pigeon populations.