Small mammals within riparian habitats of a regulated and unregulated aridland river

Publication Type:

Journal Article

Authors:

Falck, Miles J.; Wilson, Kenneth R.; Andersen, Douglas C.

Source:

Western North American Naturalist, Monte L. Bean Life Science Museum, Brigham Young University, Volume 63, Issue 1, p.35–42 (2003)

Call Number:

A03FAL01IDUS

URL:

https://www.fort.usgs.gov/publication/4117

Keywords:

Deer Mouse, Dipodomys ordii, Microtus montanus, montane vole, Ord's kangaroo rat, Peromyscus maniculatus, river regulation

Abstract:

In northwestern Colorado, flow regulation on the Green River has created a transitional plant community that features encroachment by upland vegetation into cottonwood (Populus fremontii)-dominated, riparian forest on topographically high floodplain sites and reduced cottonwood regeneration on low floodplain sites. To assess how these changes might have affected small mammal distributions, in 1994 and 1995 the authors live-trapped during periods surrounding spring flooding at 3 sites: above and below the confluence of the regulated Green River and at the ecologically similar, but unregulated, Yampa River (reference site). More species were captured at the most regulated site along the Green River above its confluence with the Yampa River. Within sites, more species were captured in riparian habitats than adjacent upland habitats. Despite river regulation-induced habitat changes, the authors did not detect changes in species distributions within low and high floodplain habitat for Peromyscus maniculatus or Microtus montanus, but changes may have occurred for Dipodomys ordii. The total effect of regulation-induced habitat change on small mammal populations may not be fully revealed until current, mature cottonwood forests disappear and associated woody debris decomposes.