| Abstract | In 1991, we conducted a pilot study to test a method for sampling avian communities on a series of lakes in northeastern Pennsylvania and to determine whether differences between undisturbed and disturbed sites could be detected from a census period consisting of two surveys taken during the breeding season. At the time, we were seeking to determine whether birds could serve as adequate indicators of changes in the condition of a variety of aquatic resources, including vegetated wetlands, riparian corridors, and lake-wetland complexes. Although few birds are completely aquatic, we have found in subsequent studies that they have the potential to be suitable indicators, as useful as entirely aquatic organisms such as fish, sediment diatoms, and zooplankton (Moors 1993, O'Connell et al. 2000, Gyekis 2007). Obviously, obligate avian species such as waterfowl, wading birds, and shorebirds rely primarily on waters for foraging, and nest proximal to shores. In addition, many terrestrial species of birds rely upon aquatic resources during all or part of their life cycle. They may feed on insects that have an aquatic larval stage that may be strongly influenced by changes in the condition of the water body. These changes may be reflected in the composition of avian communities. Data on avian communities is also relatively easy and inexpensive to obtain, often through citizen science surveys, adding another favorable aspect to their use as indicators. |
