Spatial ecology and habitat utilization of American alligators in an urban-influenced ecosystem

Cord B. Eversole, Texas A and M University-Kingsville
Scott E. Henke, Texas A and M University-Kingsville
David B. Wester, Texas A and M University-Kingsville
Bart M. Ballard, Texas A and M University-Kingsville
Randy L. Powell, Texas A and M University-Kingsville
Selma Glasscock, Welder Wildlife Foundation


Previous studies have explored spatial ecology and habitat use of alligators and other crocodilian species. However, few studies have explored these characteristics in urban environments. We studied an alligator population that occurred in an urban-influenced ecosystem, a habitat that has received little scientific attention. Our objectives were to determine spatial ecology and habitat use of American alligators within this urban system and to provide a template of methodology and analytical techniques that can be used by urban biologists, planners and researchers in order to assess and study urban crocodilian populations.We recorded 653 observations of alligators and their locations during 19 alligator surveys at an encounter rate of 0.6 alligators per km/survey. Results indicated that alligators exhibited clustering patterns of distribution. Thirteen different wetland types occurred within our survey area, but alligators were only observed in 10 of the 13. We found few differences in habitat use among size classes. We observed little segregation between adult and subadult size classes. However, there was spatial segregation between hatchlings and all other size classes, presumably due to female nest site selection. Alligators of all size classes seemingly avoided areas of high human activity; therefore, urbanization can influence alligator distribution and habitat use within wetland ecosystems. We provide methods and information that can be incorporated into future research and management of urban crocodilian populations. Utilizing this information, biologists can identify potential target areas for implementing management strategies, identify habitat and nesting areas, and mitigate human-alligator conflict.