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• XC Assignment
• Grade book to date posted on web by secret
name
Which do you think is the best
definition of the ecological ‘niche?’
a) The ecological role of a species in a community
(its ‘job’) – The Eltonian Niche
b) The range of conditions and resource
availabilities within which the individual or
species persists- The Hutchinsonian Niche
c) A physical location in the environment Habitat
d) An N-dimensional hypervolume of suitable
resources and conditions – The Hutchinsonian
Niche
e) A little nook in the wall – a different meaning
Which do you think is the best
definition of the ecological ‘niche?’
a) The ecological role of a species in a community
(its ‘job’)
b) The range of conditions and resource
availabilities within which the individual or
species persists
c) A physical location in the environment
d) An N-dimensional hypervolume of suitable
resources and conditions
e) A little nook in the wall
Examples
• Eltonian Niche (‘job’ or ‘role’) –
– ‘A bird that eats worms and is eaten by hawks’
– In North America, describes robins (Turdus
migratorius)
– In Europe that role is performed by European
blackbirds (Turdus merula) and song thrushes (T.
ericetorum)
– ‘Ecological equivalents’- common usage
• Hutchinsonian Niche
– List of requirements
• ‘worms >3/m2, 2-8cm long;
• hawks < 2/10 hectares…’
– More practical for field work
Optimum range for PSN
in low light, Alps
http://www.tropengarten.de/Bilder/B-OleEurCult.jpg
http://www.toyen.uio.no/botanisk/nbf/plantefoto/ranunculus_glacialis_Egil_Michaelsen02.jpg
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How would you characterize the
Human Niche?
The niche can be ‘n-dimensional’
In small groups discuss how to address this
question, and what you would need to
consider.
A listing of
tolerances
for each of
many
important
‘limiting
factors’
Two-dimensional niche for Sand Shrimp
(Crangon septemspinosa)
Multi-dimensional Niche requirements
Water
Water
May not exactly match those for one
dimension
Temperature
Requirements can ‘interact’
Temperature
Ecology
• Ecology = Study of the relationships
between organisms and the environment
(your book)
also
• Ecology = Scientific analysis of distribution
and abundance
– Abundance - “how many” (density)
– Distribution - Geographic extent of a
population or species
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Eastern Tiger Swallowtail
Distribution Maps
• Distribution is often summarized
using a map
• Indicates areas where the
creatures can be found
In small groups:
What limits this
distribution?
http://www.npwrc.usgs.gov/resource/distr/lepid/bflyusa/bflyusa.htm
Western Tiger Swallowtail
Tiger swallowtails
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