Interspecific Competition


Definitions
Direct (Interference) versus indirect competition
Exploitation competition (via resource depression)
Competitive exclusion
Limiting similarity, maximal tolerable overlap
Temporally varying environments
Evolutionary consequences of competition (K selection)
Ecological diversification (niche separation)
Balance between intraspecific and interspecific competition
Lab experiments
"Natural" experiments
"Real" experiments

Circumstantial Evidence from Nature

(1) studies on the ecologies of closely related species living in the same area
Resource partitioning
(2) character displacement, Typhlosaurus
Hutchinsonian Ratios (Schoener's hawks, Varanus)
Size assortment versus size displacement, Cnemidophorus
(3) studies on "incomplete" floras and faunas (Appalachian Plethodon)
Associated changes in niches ("niche shifts," niche expansion, "ecological release")
(4) taxonomic composition of communities.

Studies on Anolis
Wilbur's amphibian tank experiments, Dunham's Big Bend lizards

Niche Dimensions

(1) species exploit different habitats or microhabitats
(differential spatial utilization of the environment)
(2) they eat different foods
(3) they are active at different times
(differential patterns of temporal activity). BR>Non-independence and complementarity of niche dimensions

Anatomical Correlates of Ecology

Head length, hindleg length
Morphometric hypervolumes
Principal Components Analysis

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Last updated 6 March 1997 by Eric Pianka