Niche segregation in high-altitude Himalayan chats (Aves, Turdidae): does morphology match ecology?

摘要: We investigated patterns of habitat segregation and morphological differentiation in syntopic, closely related turdid birds the alpine zone Central Himalayas. Discriminant function analysis 19 structure parameters comparisons additional features revealed that species were distributed along gradients vegetation height density. In addition, non-vegetational structural features, like microrelief variability or presence rocks boulders, had strong discriminating power. terms preferences guild formed three subsets: shrubbery (Erithacus pectoralis, E. chrysaeus Hodgsonius phoenicuroides), preferring open areas with higher surface roughness (Phoenicurus frontalis, Chaimarrornis leucocephalus) high-altitude Grandala coelicolor. Using discriminant 20 characters, morphology was analysed relation to microhabitat utilization foraging behaviour. Species inhabiting patches shrubby thickets mainly by pedal movements (E. H. phoenicuroides) have common short rounded wings high wing loading legs feet. preferably aerial hawking "perch pounce" techniques more (P. C. chaimarrornis, some extent cyanurus) longer wings, shorter tarsi long rictal bristles. proved be well adpated for long-distance flights at altitudes (long, pointed wings) foraging. Overall our results fit basic assumption ecomorphological theory distance reflects ecological distance. The ordination each space matched its distribution (microhabitat, strategies). Striking associations ecology not only evident single traits but also found multidimensional comparisons: between-species Euclidian distances calculated from properties most cases equivalent traits. one two study locations plane spanned DFA axes use mirrored their positions multivariate space. observed distributions are interpreted as being attributable individualistic responses specific constraints environment.