Habitat Selection By Cavity-Nesting Songbirds Utilizing Artificial Nest Boxes Below High-Voltage Power Lines

Habitat destruction is one of the leading causes for population declines among cavity nesting songbirds. Management for mowers along power line cuts reduces natural breeding cavities for species such as the Carolina chickadee, Eastern bluebird, house wren and house sparrow. These four species have readily accepted artificial boxes for breeding in areas of reduced habitat, and when provided and properly placed are often occupied in the same year causing an immediate rise in these species\u27 populations (Newton, 1994). Understanding their habitat preferences when using artificial boxes is crucial for conservation. To achieve this understanding, two years of data from a 22 mile power line cut from St. Louis County to Franklin County Missouri, with boxes already placed on the line, were analyzed to determine preferences when habitat is a direct factor in fledging success. The stanchions along the cut were divided into three habitats: open field, shrub, and other. If a single fledging occurred, that box within one of the three habitats was classified as being successful. Kruskal-Wallace and Tukey test revealed that the open field habitat was statistically used more and was the most significant when success was a direct factor of the surrounding habitat. As vegetation near the boxes increased there was a steady decrease in success. Therefore habitats in similar regions should attempt to mimic this open field effect when artificial boxes are used. This will allow for a greater success in fledging, thereby helping to increase these species\u27 populations in areas where their natural cavities are lost