Data for: Genetic relatedness shapes social dynamics in a threatened finch: Implications for population assessment

Tropical granivorous finches often form large flocks around resources. The
composition of these flocks, whether they are random groups of individuals
or comprise related birds travelling together, is currently unknown.
Understanding this distinction would aid in assessing the accuracy of
population counts. To bridge this knowledge gap, we combined
high-frequency location tracking with comprehensive genetic sequencing to
investigate the relationship between pairwise association strength and
genetic relatedness in Gouldian finches (Erythrura gouldiae). Our study
revealed that birds captured near each other were more inclined to travel
together, and their relatedness was significantly linked to the strength
of their association. These findings suggest that within-flock
associations are influenced by genetic relatedness, contributing to the
stability of the flock size. We propose that juvenile kin associations
play a pivotal role in this dynamic, potentially enhancing survival rates
by forming sibling subgroups. The consistent flock sizes of Gouldian
finches during movement have implications for estimating population sizes
from waterhole counts, allowing flocks to be considered as distinct units
for concurrent counts at multiple waterholes. This approach would offer a
reasonably accurate method for estimating local populations, and
conducting repeated counts on consecutive days could provide reliable and
replicable results.