TESTING ISLAND BIOGEOGRAPHY THEORY USING SMALL MAMMALS ON ISLANDS IN LAKE LANIER, GEORGIA

• Main Authors: Ceren*, Alex, Redmon*, Mary, Bender, Dr. Michael, Martin, Gherry, O'Donnell, Kevin
• Format: Text
• Language: unknown
• Published: Digital Commons @ the Georgia Academy of Science 2019
• Subjects: island biogeography; small mammals; island; Lake Lanier; Rattus rattus
• Online Access: https://digitalcommons.gaacademy.org/gjs/vol77/iss1/102

Much has been written on the theory of island biogeography and the importance of island size and connectivity to the resident community. This theoretical work typically has been tested on large marine islands, but few studies have looked at how applicable the theory is to freshwater islands. The construction of Lake Lanier in 1956 resulted in the creation of numerous islands that, in large part, have been isolated from the mainland since the initial flooding. These islands provide an opportunity to test the applicability of island biogeography theory to the small mammal community on islands in a freshwater habitat, but we were unable to find any previous small mammal research associated with islands in Lake Lanier. Therefore, we initiated a project in which our objectives were to determine 1) if small mammals currently reside on these islands, and 2) the influence of island size and isolation on the diversity and abundance of small mammal captures. During the initial stage of this project, we surveyed small mammals on six islands in Lake Lanier using Sherman traps and snap traps from 17 September to 17 November 2018. Sampled islands ranged from 2.4ha to 60ha, and distance to shore varied (187m - 884m). We captured four mammals in 1227 trap nights including 1 black rat (Rattus rattus), 1 cotton rat (Sigmodon hispidus), and 2 chipmunks (Tamias striatus). Three of the captures were the product of 174 trap nights on the smallest island sampled, and one capture was the result of 448 trap nights on the largest island sampled. Future efforts will focus on increasing our sample size, the use of track plates to locate productive areas, evaluating the influence of island size and connectivity on our captures, and sampling mainland areas to determine how the island communities differ from the mainland community.