Northern Idaho ground squirrel population monitoring progress report for the 2009 field season

Publication Type:

Report

Authors:

Diane Evans Mack; Bond, Pamela

Source:

Threatened and Endangered Species Project E-28-8, Idaho Department of Fish and Game, Boise, p.16 (2010)

Call Number:

U10MAC01IDUS

Keywords:

northern Idaho ground squirrel, Spermophilus brunneus brunneus, Urocitellus brunneus

Abstract:

Population monitoring for the federally threatened northern Idaho ground squirrel (Urocitellus brunneus brunneus, formerly Spermophilus brunneus brunneus) occurred during April through June 2009. We examined demography and population trends at 4 of the 5 long-term monitoring sites. Collectively, 148 adults and yearlings were live-trapped. Resulting modeled population estimates showed downward trends for 4 of the sites. One other rebounded from a 2008 low. One was not sampled in 2009: numbers had dropped to a level where squirrels were difficult to encounter, requiring increasing investment in time for relatively little return.
Overall, the outlook for NIDGS improved in 2009. The population estimate of 1,618 adults and yearlings represented a 7% increase over 2008. NIDGS occupied 49 sites in 2009, although about half of these supported ≤20 adults and yearlings. The proportion of sites on federally managed land decreased as the overall number of sites increased. This changing
distribution across ownerships has implications for recovery, as partnerships with private landowners become more important.