Date of Award
Master of Environmental Studies (MES)
Seventeen Great Blue Heron (Ardea herodias) nesting colonies were studied in northeastern Indiana to determine which natural and human variables, within 15 km of each heronry, correlated with the size and location of this bird’s nesting sites. The data collected in the field and with ArcMap, a Geographical Information System program, included: the types and distances to human disturbances and water/foraging sources; wetland size and type; the height, dbh, and species of nesting trees; and the number of active and total nests. This information was used to produce an individual map for each heronry as well as a regional map for all of northeastern Indiana. With the use of two statistical tests, a best subset regression and a multiple regression analysis, 13 variables were compared to the number of active nests, and three variables were found to be significant (p-value < 0.05): distance to the nearest population center of 0-1,000, dominant wetland type within 15 km, and distance to the nearest water body. A fourth variable, distance to the nearest human habitation, was found to be of some importance with a p-value of 0.059. The mean distance to the nearest population enter of 0-1,000 was 2.85 km, the dominant wetland type with 15 km was PFO1A, and the mean distance to the nearest water body was 64 m. It was also found that GBHE would frequently use American sycamores or American beeches when nesting in riverine or upland forest habitats respectively. These analyses showed the importance of forested buffer zones along all riverine and wetland habitats where nesting and foraging by Great Blue Herons occurs.
Kauffman, Jason M., "Geographical Information System Analysis of Great Blue Heron (Ardea herodias) Colony Site Selection in Northeastern Indiana" (2006). Master of Environmental Science (MES) Theses. 2.