FORAGING CHOICES OF A SMALL HETEROMYID MOUSE IN COASTAL SAGE SCRUB HABITATS

Devin Adsit-Morris; U.S. Geological Survey; dadsit-morris@usgs.gov; Cheryl Brehme, Amy Vandergast, Robert Fisher

Preferred Session: Natural History of Small Mammals or Military Lands Poster 

Abstract: We present a field study on seasonal diet and foraging choices of the endangered Pacific Pocket Mouse (PPM) in 2 of 3 remaining extant populations of this species. Detailed life history studies have revealed that PPM is fossorial with a complex life history that involves the use of torpor to remain dormant during the Fall and Winter, however little is known about their foraging choices. Knowledge of the dietary habits of PPM is essential to establishing a robust management and rehabilitation plan aimed at providing PPM habitat with adequate forage quality (i.e. nutrient composition) and quantity (i.e. food abundance). Such habitat is imperative for individual growth and survival. We conducted trapping, habitat surveys (including plant phenology status), and metabarcoding of scat from PPM and competitors located in MCB Camp Pendleton, California. We evaluated the proportion of a food type in diet and selectivity for it in relation to availability using linear mixed effect models. Better understanding of PPM diets and competitor diet overlap can help identify factors that influence PPM foraging patterns and identify food resources that should be prioritized by land managers and habitat restoration projects to provide food resources for PPM across their entire foraging season.

Poster Session