atoll fern

White tern habitat selection : Gygis alba

white tern chick on Tetiaroa atoll

White tern habitat selection : Gygis alba

We conducted an atoll-wide survey of the distribution of white tern eggs and chicks between December 2022 and May 2023 to determine what affects nest site selection for white terns (Gygis alba).

Principal Investigators: Jayna DeVore, Simon Ducatez, Antoine Vansse
Affiliations: Université de Polynésie Française, French National Institute for Sustainable Development
Project Dates: December 2022 – May 2023

Image
white tern chick

Utilizing data collected along 52km of interior transects and 35km of coastal transects, this study was conducted at both the macro scale (importance of the type of forest, distance to the coastline, or rat/ant invasion history) and micro scale (importance of the tree species, branch height and branch length and orientation).

Image
white tern egg

Data from 460 nests revealed that both macro and micro scale elements are important for nesting site selection in this species, and that these elements can have consequence for nesting success. For example, branch thickness, slope, curvature, and angle to the dominant wind all affected the likelihood that an egg would survive to hatching.