Open Access. Powered by Scholars. Published by Universities.®

Ecology and Evolutionary Biology Commons

Open Access. Powered by Scholars. Published by Universities.®

Behavior and Ethology

PDF

2012

Competition

Articles 1 - 2 of 2

Full-Text Articles in Ecology and Evolutionary Biology

Winter Microhabitat Foraging Preferences Of Sympatric Boreal And Black-Capped Chickadees In Michigan's Upper Peninsula, Alec R. Lindsay Ph. D., Zach G. Gayk Dec 2012

Winter Microhabitat Foraging Preferences Of Sympatric Boreal And Black-Capped Chickadees In Michigan's Upper Peninsula, Alec R. Lindsay Ph. D., Zach G. Gayk

Faculty Works

We examined differences in microhab- itat use between Boreal (Poecile hudsonicus) and Black- capped chickadees (P. atricapillus) where they co-occur near Marquette, Michigan, USA. Twenty-four Boreal and 37 Black-capped chickadees were followed during 60 hrs of field observation. Boreal Chickadees foraged only in three conifer species, 76% of which were black spruce (Picea mariana), while Black-capped Chickadees foraged widely across six coniferous and three deciduous tree species. Analysis of foraging data categorized by zones within conifer trees indicated high niche overlap (0.676) between Boreal and Black-capped chickadees across all foraging zones. Individual comparisons on a zone-by-zone basis revealed a significant …


Intraspecific Density Dependence And A Guild Of Consumers Coexisting On One Resource, Mark A. Mcpeek Dec 2012

Intraspecific Density Dependence And A Guild Of Consumers Coexisting On One Resource, Mark A. Mcpeek

Dartmouth Scholarship

The importance of negative intraspecific density dependence to promoting species coexistence in a community is well accepted. However, such mechanisms are typically omitted from more explicit models of community dynamics. Here I analyze a variation of the Rosenzweig-MacArthur consumer–resource model that includes negative intraspecific density dependence for consumers to explore its effect on the coexistence of multiple consumers feeding on a single resource. This analysis demonstrates that a guild of multiple consumers can easily coexist on a single resource if each limits its own abundance to some degree, and stronger intraspecific density dependence permits a wider variety of consumers to …