An increasing number of feral cats roam the United States presently, leading to increased ecological damage to native wildlife and incidence of disease for the cats. Common methods of controlling overpopulation usually involve active management via TNR (Trap-Neuter-Release) with varying results. In theory, TNR might work in closed populations, i.e. populations in which no new individuals were entering the population. However, studies estimating immigration and emigration rates of cats into feral colonies are lacking, causing the true effectiveness of these programs to be subjective. The purpose of this study is to add crucial quantitative data on those rates in feral cat colonies with implications for population management. Such data will assist in determining if current methods for population management are effective, or how they can be improved. This study was conducted through visiting 3 feral cat colonies and using standard sampling methods. Photographic records and detailed field notes were collected on each visit to determine if any new cats were present or missing. Colonies were visited 3 times per week and each cat was identified by color and distinguishing marks. Results of this study are currently pending however, based on the data collected thus far we estimate that immigration and emigration rates at our colonies are less than previous published studies. Should results hold, it would suggest that current methods for managing these colonies have been effective. However, without proper education and dissemination of information, we cannot create a collaborative effort in enforcing these programs and eradicating the overpopulation problem.