Chemisty

PaciiicSouthwest Research Service, Staton CynthiaJ. Zabel and Jeffrey R.Waters U.S Forest Arcata Ca forna 95527 T700 Baw ew Drlve,

Food Preferences CaptiveNorthernFlyingSquirrelsfrom the Lassen of Forestin Northeastern California National

Abstract

Hypogeous sporocarps myconhizal fungi (truffles) are a common food ofnorthem llling squinels lAhucottl)5 sabrinus) 8nd ol practicesand natural disturbances can allecl both lotal amountsand many other speciesof small mammals, Forest management speciescompositxrn of truflles- We conductedcafcteria style feedjng trials to compdreprelerencesof nofthern flying squirels capturedin the LassenNational Forest in nonheastemCalifomia among sporocarprof 5 speciesoffungi (3 trutrle speciesand 2 speciesofsecoiiojd fungi).2 speciesoflichens. and fit @bies mas ifu andA..orcolo.) seeds- Feedingtrials were pedormed on 7 nrale squinels for 4 consecutivenights. Mean proportic,nof food caten varied significantly among the 3 truffle species, bctween lhe 2 speciesof secotioidfungi, and betweenlhe 2lichcn species. Mean proportion of food eatenwas gfeateslfor 2 of the lrullle rpecies.followed by the lichen B,-lor"idli.rroxrii. Thcseresultsjndicatethat northernflying squiffels prefered truffles over certain types of oiher naturally occuning ibods. and that preterencevaried significantly anong sporocarpsof difierenl fungal species. Natural disturbanceand lbrest nanagement thai alter the speciescomposition of fungat sporocarysare likel) to afect the availability of foods preferfedby nor$em ilying squinels.

lntroduction

Numerous species of small mammals feed on hypogeous sporocapsof mycorrhizalfungi (here"tuffles") in temperateand atter referred to as tropical foreststhroughoutthe world (e.g.,Tevis Maseret al. 1978, 1953,FogelandTrappe1978, Taylor 1992,Johnson1994,Janoset al. 1995). Some species,such as the nofthem flying squir rel (C laucomy sabrinas),Califomia red-backed s vole (Clethrionomyscallbrnlcls) (Ure and Ma ser 1982),and various...