Immediate Effects of Hardwood Removal and Prescribed Burning on Bird Populations

Abstract

Censusing of bird populations in three forest habitats was conducted from March 1966 through February 1968 in Nacogdoches County, Texas. The three habitats consisted of: (1) a pine stand in which all hardwoods had been killed or removed, (2) a pine-hardwood stand which included 25 per cent hardwoods, and (3) a control unit that included 36 per cent hardwoods, which had not been cut for several years. Hardwood removal and the following prescribed burn opened up the canopy, which resulted in dense growth of the understory. Major finds and con- clusions of this study are: (1) The total number of birds in the three areas did not differ statistically during the first year prior to the prescribed burn. (2) Prior to burning, the area of complete hardwood removal supported the most kinds of birds. (3) Prior to burning, the red-eyed vireo (Vireo olivaceus) was the only species showing a significant difference in nesting density. (4) Following burning, the number of birds in the partial hardwood removal area increased whereas the number in the control area decreased. (5) The species showing significant increases after burning were Carolina chickadee (Parus carolinensis) yellow-shafted flicker (Co- laptes auratus), slate-colored junco (Junco hyemalis), and robin (Turdus migra- torius). (6) Species diversity varied from 2.74 to 2.89, with differences not statisti- cally significant. (7) Number of species varied from 19 to 24, and number of adult breeding birds per 100 acres varied from 1012 to 1350. The increasing importance of lumbering and pulpwood industries in Eastern Texas is resulting in more intensive management practices in natural forested areas. Major emphasis in fbrest management is directed towards increased production of pine timber due to the greater commercial value and more rapid growth potential. This often involves the removal of hardwood species which alters the structure of the forest community. Foresters are interested in the quality and quantity of timber but if bird numbers are reduced a harmful increase in insect populations might result. The objectives of this study were to deter- mine: (1) density, (2) nesting population, and (3) seasonal fluctua- tion of birds following hardwood removal and prescribed burning.