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Angela Larsen ACF Abstract FY11

"Effects of forest thinning on predator-prey relationship between white-footed mice and gypsy moth pupae in west central Michigan"

Conference Name: The Wildlife Society Annual Conference

White-footed mice (Peromyscus leucopus) are a main predator of gypsy moth (Lymantria dispar) late-stage larvae and pupae.  This study will investigate whether these predation rates are different between areas subjected to different forest thinning methods and whether there are other small mammal species contributing to these predation rates.  Two sites undergoing forest thinning for oak savanna restoration in the Manistee National Forest in Lower Michigan will be monitored and compared.  One site, Pines Point, was thinned with downed wood piled while the other site, Hayes Road, was thinned with downed wood left where it fell.  There are five experimental replicates at each site that consist of four 2 acre plots; 3 treated with separate mechanical tree thinning techniques (masticator, bulldozer, shearcutter), and a control plot.  Small mammal trapping and gypsy moth egg mass counts will be conducted to estimate abundance and density of both of these populations.  Predation rates on gypsy moth pupae will be measured by monitoring live pupae placed in the field.  Track plates and teeth marks will be used to identify the mammalian predators involved.  Predation rates are expected to be different between sites, but not between thinning techniques.  The results will aid forest managers in choosing thinning methods when keeping gypsy moth populations at low densities is a priority.