Songbird Responses to Commercial Clear-Cutting in Maine Spruce-Fir Forests

Abstract

In commercially clear-cut and uncut spruce-fir (Picea-Abies) stands of northern Maine, the distribution of breeding songbirds was determined by habitat structure. We grouped 14 sampling areas into 5 seral stages. Stage I was characterized by dense slash and open ground, Stage II by dense raspberry stems and deciduous woody stems less than 2 m tall, Stage III by deciduous woody stems 2.1-4.5 m tall, Stage IV by deciduous woody stems taller than 4.5 m and trees with dbh 10-15 cm, and Stage V by a dense softwood overstory. Presence or absence of a softwood overstory was the most important habitat feature. Each seral stage was dominated by a characteristic group of breeding bird species. The data showed a predictable pattern in response of the breeding avifauna to changes in habitat structure following clear-cutting. J. WILDL. MANAGE. 43(3):602-609 There have been few studies on the effects of clear-cutting on birds in coniferous forest ecosystems, and none has dealt with this problem in spruce-fir forests in the northeastern U.S. Hagar (1960) in California and Franzreb (1975) in Arizona found marked changes in bird species composition following commercial clear-cutting in Douglas-fir (Pseudotsuga mensiesii) forests. In coniferous forests of Finland, Haapanen (1965) found that changes in the bird species using various stages of forest succession following timber harvest were due to changes in habitat structure of the forest stands. We examined the relationships between breeding songbirds and commercial clear-cutting in northern Maine. Our objective was to identify the habitat characteristics to which songbirds respond in clear-cut spruce-fir forests. The USDA Forest Service provided funding for this study through a cooperative agreement between the School of Forest Resources, University of Maine, Orono, and the Northeastern Forest Experiment Station. W. A. Wright, N. C. Famous, A. Kerr, M. S. Robson, L. A. Wright, and T. L. Stone helped with the bird and vegetation inventories. We thank M. W. Coulter, R. B. Owen, and R. M. Frank for their reviews of the manu-