A comparison of habitat use and demography of red squirrels at the southern edge of their range

Katherine M. Leonard, John Koprowski

Research output: Contribution to journalArticle

6 Citations (Scopus)

Abstract

Populations at the edge of their geographic range may demonstrate different population dynamics from central populations. Endangered Mt. Graham red squirrels (Tamiasciurus hudsonicus grahamensis), endemic to southeastern Arizona, represent the southernmost red squirrel population and are found at lower densities than conspecifics in the center of the range. To determine if differences are due to conditions at the southern periphery of the range, we compared habitat characteristics, demography, body mass, space use and nesting behavior with another subspecies located at the southern edge of the range, the Mogollon red squirrel (T. h. mogollonensis). We found that mean and minimum daily temperatures were higher at Mt. Graham whereas maximum temperatures were higher in the White Mountains, male Mogollon red squirrels were heavier than male Mt. Graham red squirrels in all seasons and female Mogollon red squirrels were slightly heavier than female Mt. Graham red squirrels in spring, proportion of squirrels in reproductive condition was lower in female Mogollon red squirrels, Mogollon red squirrels had smaller home ranges, used different types of nests and traveled less distance to nest than Mt. Graham red squirrels. There were no differences in annual rainfall, seedfall, habitat characteristics or survival between mountain ranges. Localized conditions appear to account for the disparity between populations. These differences demonstrate the importance of evaluating attributes of peripheral populations for maximizing persistence and intraspecific diversity.

Original languageEnglish (US)
Pages (from-to)125-138
Number of pages14
JournalAmerican Midland Naturalist
Volume162
Issue number1
DOIs
StatePublished - Jul 2009

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squirrels
demography
habitat use
nest
habitats
nesting behavior
space use
habitat
home range
body mass
subspecies
population dynamics
persistence
rainfall
mountain
comparison
nests
mountains
Tamiasciurus hudsonicus
temperature

ASJC Scopus subject areas

  • Ecology, Evolution, Behavior and Systematics

Cite this

A comparison of habitat use and demography of red squirrels at the southern edge of their range. / Leonard, Katherine M.; Koprowski, John.

In: American Midland Naturalist, Vol. 162, No. 1, 07.2009, p. 125-138.

Research output: Contribution to journalArticle

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