Профиль

With co-authors @meg-crofoot.bsky.social, @ggfinerty.bsky.social , Susan Perry & @bjjbarrett.bsky.social, at @mpi-animalbehav.bsky.social @uni-konstanz.de, and UCLA.

None of this would have been possible without the Lomas Barbudal Monkey Project, founded by Susan Perry in 1990 — one of the longest-running primate field studies in the world. 🌳🐒 The power of long-term data.

Group sizes vary widely in nature. Our results suggest a reason why: group size is not a fixed advantage or disadvantage. It can impose costs within groups, yet become an asset between groups, with the balance shifting across environmental contexts.

Interannual climate variability changed the trade-off too. Across El Niño and La Niña cycles, ENSO reshaped the costs and benefits of group size, with extreme conditions amplifying the costs of living in a large group.

In Costa Rica’s tropical dry forest, the dry season concentrates resources along riverine habitat. During this period, home ranges overlapped less, but inter-group encounters spiked, with larger groups occupying the best-quality patches.

Group size matters. Relative group size matters more. Under typical conditions, larger groups paid a clear cost: individuals foraged less efficiently. But they compensated by expanding their ranges, and did so disproportionately toward smaller neighbors.