Survival of Ruffed Grouse Chicks in Northern Michigan

Abstract

Knowledge of the survival rates of ruffed grouse (Bonasa umbellus) chicks during the predispersal period is necessary for effective population management. We marked 76 ruffed grouse chicks using 2 radiotransmitter attachment procedures to determine the chick survival rate. Chick survival from near hatching (9-14 Jun) to fall dispersal (7 Sep) was 0.285 (SE = 0.098) in 1996 and 0.318 (SE = 0.087) in 1997. These rates were considerably lower than previous survival estimates for ruffed grouse chicks. Suturing transmitters externally was preferred over implanting them. Avian predators were the leading cause of chick mortality. Therefore, managers should consider the densities of avian predators when defining objectives for ruffed grouse recruitment.