Breeding Habitats of the Wood Thrush and Veery

scientific study. In very few cases, however, do we understand why a species occurs in a particular habitat, either in an ultimate (evolutionary) sense or a proximate (behavioral) sense. Before these questions can be adequately approached, a knowledge of the quantitative aspects of species' habitats is necessary. Most information on this subject comes from comparative habitat analyses (e.g., Sturman 1968, Wiens 1969, James 1971, Anderson and Shugart 1974). Vegetation structure has been emphasized heavily in such studies and often has been adequate to measure habitat differences among species. Floristic and physical factors have received less attention although MacArthur (1964) suggested that the latter may be important for at least some species. This study examines quantitatively the habitats of two woodland thrushes, the Wood Thrush (Hylocichla mustelina) and the Veety (Catharus fuscescens). My purposes were to determine how and to what extent their habitats differed and to indicate factors which seemed to be favored by each species in its selection of habitats. Some physical and floristic, as well as structural, habitat features were included to examine their effects on the