Niche

• Definitions
  • 1904 Grinnell: a distributional unit that describes where an organism lives
  • 1927 Elton: an organisms functional role in a community
  • 1958 Hutchinson: a n-dimensional hypervolume
    • every point in a space that corresponds to where an organism can live
  • Note the way definitions progess towards emphasizing connectivities and the uniqueness of habitats and organisms
  • Important to remember that niche includes both biotic and abiotic factors

• Competitive Exclusion Principle: (Gause's Principle)
  • No two species can inhabit the same niche
  • Biotic and abiotic factors are arranged in such a way that species are utilizing resources in different ways
  • Fundamental question: does this negate the concept of competition in nature?

Warbler Niche Structure

• Each species utilizes a different aspect of the tree's habitat to reduce competition with other species
• This allows multiple species to extract resources from the same location.

Ways to Create Multiple Niches in the same Habitat

• Temporal: noctural vs. diurnal animals, owls and hawks each feed on rodents but at different times
• Spatial: Warbler example, use different spaces within a habitat
• Functional: Extract different resources, woodpeckers eat insects, finches eat nuts