Ecological niche partitioning in a fragmented landscape between two highly specialized avian flush-pursuit foragers in the Andean zone of sympatry

Abstract

In the Andes, pairs of ecologically similar species are often separated by narrow elevational sympatry zones but the mechanisms mediating sympatry are not fully understood. Here, we describe niche partitioning within a sympatry zone in a fragmented Andean landscape between two closely related flush-pursue species: a high-elevation montane forest dweller, (Myioborus melanocephalus), and a mid-elevation montane forest dweller, (M. miniatus). As all flush-pursuers use very similar hunting techniques involving visual displays to flush and pursue insects in air, and benefit from being the “rare predators”, ecological sorting between species in sympatry zones should allow their co-existence. We found that both species occupied vegetation resembling their typical allopatric habitats: a mosaic of pastures, clearings, and shrubs with small proportion of high trees for M. melanocephalus, and dense high forests with high proportion of trees, lower irradiance and higher humidity for M. miniatus. M. melanocephalus often foraged in bushes and at lower heights, whereas M. miniatus often foraged in tree crowns. The two species differed relatively little in their foraging technique. These results demonstrate how ecological sorting permits species of divergent elevational distributions and habitats to successfully coexist in sympatric zones where habitat diversity allows both species to find their preferred habitat.

Niche partitioning in a cyanobacterium through divergence of its novel chlorophylld-based light-harvesting system

“…During the process of novel trait diversification, populations might begin to partition the new niche space to avoid intraspecific competition (11). This partitioning may be temporal (12, 13), spatial (14), or with respect to resource utilization (11). The latter involves character displacement, i.e., an evolutionary change in a morphological, physiological or other trait that enables specialization on a specific resource (15).…”

Microhabitat segregation, foraging behavior, and elevation enable coexistence of new world warblers (Aves: Parulidae) in agroforestry systems

“…Although studying and understanding these interactions is challenging, closely related species which interact in narrow ecological zones can provide a good system to understand these processes (Patterson et al 1998, Jablonski et al 2020. This is the case of several bird species in Family Parulidae that are well known as models for numerous ecological and behavioral studies of niche partitioning (MacArthur 1958, Freckleton and Harvey 2006, Lovette and Hochachka 2006, Rabosky and Lovette 2008, Jablonski et al 2020.…”