Home range characteristics and correlates in tree squirrels

Abstract

Home range patterns of squirrels in the genera Sciurus and Tamiasciurus are reviewed. Emphasis is placed on the need to use analytical techniques which are appropriate to the questions of interest, and certain weaknesses in published studies are outlined. Variation in home range size between different species, populations of the same species and individuals of the same population is discussed in relation to ecological theory and the biology of tree squirrels. Larger species do not necessarily have larger home ranges. There is an inverse relationship between home range size and population density, but its interpretation is not clear in the absence of experimental studies. Differential utilization of space within the home range is considered to be a common pattern, although it is rarely explicitly described in tree squirrel studies. In general, species of the genus Tamiasciurus defend exclusive territories, whilst those of the genus Sciurus do not. Explanations for these patterns are discussed in terms of ‘economic defendability’ and resource heterogeneity. Problems for future study are suggested.

The response of tree squirrels to fragmentation: a review and synthesis

“…Increased interaction rates (Zenuto, Vassallo & Busch, 2002), increased wounding (Boonstra & Boag, 1992;Zenuto et al, 2002;Macdonald et al, 2004), increased weight loss (Macdonald et al, 2002) and reduced frequency or age of first reproduction (Wolff, Schauber & Edge, 1997;Rodel et al, 2004) can occur in high density populations. In tree squirrels, home-range size is negatively related to density (Don, 1983) and communal nesting is frequent in small urban woodlots (Taylor, 1969;Koprowski, 1996). The propensity of female eastern grey squirrels to remain in their natal areas to form overlapping generations of kin as well as to nest in large groups (Koprowski, 1996) may further explain the ability of the alien species to invade and displace the solitary native Eurasian red squirrels .…”

“…Assessing the impacts of forest fragmentation on this group is thus quite timely. Previous studies of individual species in a local area have suggested that home-range size or density may be related to woodlot size (fox squirrels, Sciurus niger: Baumgartner, 1943;Sheperd & Swihart, 1995; eastern grey squirrels, S. carolinensis : Erossy, 1973;Don, 1983;Fisher & Merriam, 2000; red squirrels, Tamiasciurus hudsonicus: Bayne & Hobson, 2000). Herein, a comparative generalised individuals-area relationship (Gaston & Matter, 2002) approach will be used across species and geographical areas to assess the response of tree squirrel density and home-range size to forest fragmentation.…”

Evidence for West Nile Virus Spillover into the Squirrel Population in Atlanta, Georgia

“…We did not detect significant differences in seroprevalence among squirrels collected in different sites, although the distance between trapping locations of our study was higher than the small home range (usually < 5 ha) (Don 1983) of squirrels in urban areas, where food availability is high. Furthermore, the distance between trap locations was smaller than the home range of primary and secondary vectors for WNV (Brust 1980, Hamer et al 2014, indicating that mosquitoes can transmit the virus to the squirrel population of Grant Park without creating spatial heterogeneity.…”

“…The home range of squirrels is limited compared to that of birds, and, thus, they may indicate the potential for virus spillover to mammals on a local scale (Don 1983, Koprowski 1994, Whitaker and Hamilton 1998. Eastern gray squirrels may be a useful indicator of local virus transmission because they breed twice annually, and seroprevalence in juveniles can be used to detect virus transmission during the WNV transmission season (Whitaker and Hamilton 1998).…”

Optimal sampling for radiotelemetry studies of spotted owl habitat and home range.

“…In keeping with Burt's (1943) definition and subsequent practice (Anderson 1982, Bekoff and Mech 1984, Burt 1943, Dice and Clark 1953, Don 1983, Ford and Krumme 1979, Harvey and Barbour 1965, Koeppl and Hoffmann 1985, Koeppl and others 1985, MacDonald and others 1980, Odum and Kuenzler 1955, Stickel 1954, we removed the 5 percent of locations most distant from the arithmetic center of the data from each of two byseason subsets of the data and repeated the analyses.…”