Vocal Complexity Constrains the Dear Enemy Effect: A Comparative Study of Coal Tits and Green-Backed Tits.

ABSTRACT: The "dear enemy effect," wherein territorial animals exhibit reduced aggression toward familiar neighbors compared to strangers, is a widespread strategy to minimize energy expenditure on territory defense. However, whether and how this behavioral capacity varies across with differing vocal complexity remains poorly unclear. We investigated neighbor-stranger discrimination (NSD) in two sympatric tit species that exhibit a stark contrast in song repertoire complexity: coal tits (Periparus ater) and green-backed tits (Parus monticolus). Acoustic analysis revealed that coal tits possessed a large population-level song-type diversity (19 distinct song types) and, crucially, a significantly larger individual syllable repertoire size compared to green-backed tits (5 song types). Pl

SUBMITTER: Zhao L 

PROVIDER: S-EPMC12789649 | biostudies-literature | 2026 Jan

REPOSITORIES: biostudies-literature