is patch use determined by fine-scale microhabitat differences or density dependent habitat selection?
abstract
if individuals base their patch and habitat choices on fine-scale differences in
microhabitat, then their use o f patches, defined by capture sites, should correspond with
measures o f microhabitat. but if individuals assess and respond to habitat at larger spatial
scales, then site use should correspond with habitat selection at those scales. i tested these
predictions by monitoring the distribution of meadow voles (microtus pennsylvanicus) in
0.25ha old-field enclosures in northern ontario, canada (the 阿根廷vs墨西哥竞猜
habitron). i varied the population density in two pairs of adjacent enclosures and tested for
habitat selection with habitat isodars. three of four isodars were statistically significant,
but even so, meadow voles were vague density-dependent habitat selectors. the use of
capture sites was related to microhabitat only in the one case where isodars failed to detect
density-dependent habitat selection. otherwise, site use was related to the number of
animals living in paired enclosures. site use by meadow voles was determined primarily
by density-dependent habitat selection.
collections
- retrospective theses [1604]