BIRD POPULATIONS AND HABITAT IN BACILLUS-THURINGIENSIS AND DIMILIN-TREATED AND UNTREATED AREAS OF HARDWOOD FOREST

The objective of this study was to evaluate the effects of a gypsy mot h (Lymantria dispar) infestation on nongame bird populations and habit at This study was conducted at the Sleepy Creek Public Hunting and Fis hing Area in Morgan and Berkeley counties, and Cacapon State Park in M organ County, in the eastern panhandle of West Virginia We compared an area that was repeatedly defoliated by the gypsy moth (Sleepy Creek) to an area (Cacapon) that was sprayed,vith Dimilin and Bt to control g ypsy math populations. Both areas were sampled in 1984, before defolia tion or spraying, and afterwards in 1993. Tree mortality caused by gyp sy moth defoliation created gaps in the canopy, increasing habitat pat chiness at Sleepy Creek, but did not negatively affect total bird dens ity. Greater habitat complexity (particularly increases in snags, wind fall and shrub cover) after the gypsy moth outbreak may have increased available nesting and foraging resources for many bird species. While habitat for some flycatchers and canopy-dwelling species was reduced at Sleepy Creek, sufficient canopy was left after defoliation to suppo rt similar numbers of these birds. Despite dramatic visual effects, gy psy moth impact may not be permanently damaging to bird populations an d may even be beneficial for some species. However, other factors, suc h as insect availability, nesting success, predation and cowbird paras itism need to be examined in gypsy moth-impacted areas to better asses s effects of defoliation on bird populations.