Sapsucker Feeding Damages Crown-Released Yellow Birch Trees

Feeding damage by yellow-bellied sapsucker (Sphyrapicus varius varius L.) was evaluated in yellow birch crown-release studies in the Upper Peninsula of Michigan. The frequency and intensity of sapsucker feeding activity was related to crown-release with the most severe damage being inflicted on the more heavily released trees. Vigorous dominant poles were fed on more often than less vigorous codominant and intermediate poles, and sapsuckers preferred yellow birch trees as a summer food source over all other available tree species. Feeding holes were concentrated in an area on the main stem within the lower portion of birch crowns and just beneath them. Sapsucker feeding reduced annual growth of host trees, and top dying above girdles was often observed.