The cost of reducing point‐count duration in urban bird monitoring across seasons
Riccardo Alba, Giacomo Assandri, Enrico Caprio, Valeria Ferrario, Simon Gillings, Luca Ilahiane, Fabio Marcolin, Diego Rubolini, Dan ChamberlainPoint counts are a fundamental tool in avian ecology, yet the consequences of changing count duration remain poorly quantified, particularly across seasons and spatial scales. Using 660 time‐partitioned point‐count visits at 220 points in six Italian cities during the breeding and wintering seasons, we assessed the effect of reducing count duration from 10 to 5 min on per‐visit ( α ) and city‐wide ( γ ) species‐richness and on abundance, and tested whether losses were predicted by species traits. Five‐minute counts captured 81% of point‐level richness during breeding and 77% in winter, and missed up to 20% of the species recorded city‐wide by 10‐min counts in winter; winter losses were concentrated in migratory and small‐bodied species, whereas abundance retention (c. 81%) did not differ between seasons. Five‐minute counts may therefore suffice for abundance indices of common species, but not for describing community composition.