INFLUENCE OF DIVERSIONARY FOOD ON RED SQUIRREL POPULATIONS AND DAMAGETO CROP TREES IN YOUNG LODGEPOLE PINE FOREST

This study was designed to test the hypothesis that large-scale provis ion of diversionary food (sunflower seeds) would reduce red squirrel ( Tamiasciurus hudsonicus) feeding damage to lodgepole pine (Pinus conto rta) crop trees. Study areas with managed lodgepole pine stands were l ocated near Vernon and Quesnel in south-central British Columbia, Cana da. Large-scale applications of sunflower seeds were conducted on a ma nual basis in 1989, and by manual and aerial means in 1990, and on an operational level by aerial means in 1991. Feeding damage to crop tree s was assessed in control and treatment blocks. Populations of the red squirrel, northwestern chipmunk (Eutamias amoenus), and Columbian gro und squirrel (Spermophilus columbianus) were sampled intensively by li ve-trapping on control and treatment blocks in 1990. Manual applicatio n of seed (clumped distribution) significantly reduced damage in the t reatment block (11.3% of trees damaged) compared with the control (57. 5% of trees damaged). Aerial application of seed (uniform distribution ) also significantly reduced damage in replicated treatment vs. contro l blocks. Provision of diversionary food resulted in a temporary incre ase in the overall number of red squirrels caught on the treatment are as followed by a return to control levels within 6 wk. This increase w as primarily the result of an increased number of transients in the tr apped sample. The population density of resident (transients excluded) red squirrels did not increase when diversionary food was added. Simi larly, we could not detect differences in reproduction, body masses, o r survival of squirrels between control and food-supplemented areas. N orthwestern chipmunks and Columbian ground squirrels also showed a tem porary increase in density when food was added. Application of sunflow er seed on an operational basis significantly reduced damage by squirr els in replicated study areas covering three different forest ecologic al zones. Provision of diversionary food is an effective strategy to p rotect intensively managed stands of lodgepole pine from red squirrel feeding damage.