iDiv Annual Conference 2026

Despite population declines, energy demand has remained broadly stable in North American bird communities

Not scheduled

20m

Talk Approaches of integrative biodiversity research

Speaker

Daria Lipsky (iDiv)

Description

Bird communities are fundamental to ecosystem functioning, yet how their community reorganisation under global change affects ecosystem energetics remains poorly understood. Using 58 years of North American Breeding Bird Survey data from 5,870 routes (1966-2023), we tracked co-variation among species richness, abundance, community evenness, and community-level energy demand. Total abundance declined sharply while species richness remained stable, producing increasingly even communities. Counterintuitively, community-level energy demand did not decline in parallel; instead, it remained broadly stable, sustained by a compensatory rise in mean body mass and trophic level driven by increasing numbers of vertebrate specialists. A strong empirical coupling between per-individual energy demand and abundance underlies this stability, revealing a functionally critical community reorganisation invisible to conventional diversity metrics.