DAMAGE TO APPLE-TREES ASSOCIATED WITH WOODCHUCK BURROWS IN ORCHARDS

Wildlife damage to apple trees causes significant production losses in the United States. To determine whether woodchuck (Marmota monax) act ivity was associated with reduced apple production, we quantified dama ge to apple trees growing <1.5 and 12-15 m from 58 active woodchuck bu rrows in 3 Connecticut orchards. Ninety-six percent of live trees near burrows had been gnawed by woodchucks, whereas no trees 12-15 m away had been gnawed. Incidence of death was 17 and 0% for trees <1.5 and 1 2-15 m away from burrows, respectively. Height, maximum canopy width, and stem diameter 0.5 m above ground were less (P less-than-or-equal-t o 0.001) for trees adjacent to burrows than for trees of the same age and variety 12-15 m away. Trees 12-15 m from burrows produced 1.8 time s as many apples as trees adjacent to burrows. Apples produced near bu rrows, on average, weighed less (P < 0.05) than apples produced 12-15 m away in 3 of the 7 plantings. Control of woodchucks may be warranted in orchards with burrow densities >3/ha.