Bird co-occurrences remain largely stable despite widespread biodiversity change

Bird pairwise co-occurrence patterns across four breeding bird atlas datasets spanning five decades in Europe, Czechia, New Zealand, and New York State remain largely stable.

• Why it matters: Species turnover is often taken as evidence of community reorganization, but it is unclear whether changing communities also alter spatial associations among co-occurring birds.
• What they did: The study quantified temporal change in bird co-occurrences using four breeding bird atlas datasets across five decades, then simulated independent species movement to test whether turnover alone explains observed association shifts.
• The result: Pairwise co-occurrence changes were balanced around zero, largely independent of pairwise traits, and most associations showed no change, implying environmental change may shift species coherently while preserving relative spatial associations.