Fall-winter survival, habitat, and long-term population change of ruffed grouse in New York State

In New York, ruffed grouse (Bonasa umbellus) abundance has declined since the 1960s, presumably due to forest maturation. Wildlife managers expressed concern that harvest may contribute to grouse decline as habitat quality decreases. We monitored the fall-winter survival of 169 radio-marked grouse at 2 study areas differing in forest age and composition. We examined 1980 and 2000 Breeding Bird Atlases to relate declines in grouse to landscape-level habitat factors. Fewer than 11% of radio-marked birds were harvested and survival was equivalent at the 2 study areas. Regionally, grouse decline was positively related to declines in amount of area of early successional forest (R 2 = 0.76). Grouse disappeared in marginal areas of their distribution and in areas with low amounts of forest and landscape configurations potentially advantageous to nest predators. We conclude that harvest is not the driver of grouse decline in New York, but declining habitat quality has contributed to low recruitment.;Key words: autologistic regression, Bonasa umbellus, Breeding Bird Atlas, forest maturation, New York State, occupancy, radiotelemetry, ruffed grouse, survival.