Airborne imagery does not preclude detectability issues in estimating bird colony size.

ABSTRACT: Aerial images obtained by drones are increasingly used for ecological research such as wildlife monitoring. Yet detectability issues resulting from animal activity or visibility are rarely considered, although these may lead to biased population size and trend estimates. In this study, we investigated detectability in a census of Malagasy pond heron Ardeola idae colonies on the island of Mayotte. We conducted repeated drone flights over breeding colonies in mangrove habitats during two breeding seasons. We then identified individuals and nests in the images and fitted closed capture-recapture models on nest-detection histories. We observed seasonal variation in the relative abundance of individuals, and intra-daily variation in the relative abundance of individuals-especially immature bird

SUBMITTER: Couturier T 

PROVIDER: S-EPMC10864377 | biostudies-literature | 2024 Feb

REPOSITORIES: biostudies-literature