Master's Theses



Degree Name

Master of Science (MS)


As of 2002, estimates of free-roaming domestic cat (Felis catus) populations exceeded 100 million individuals, throughout the United States. Many lost or abandoned cats will revert to living outdoors as free-roaming individuals. To try to control the abundance of free-roaming cats, trap-neuter-release (TNR) programs have been implemented across the United States. The goal of many TNR programs is to reduce cat populations by sterilizing the individuals to prevent breeding, while also providing food and water to the unconfined colony. However, wildlife conservationists question the effectiveness of TNR programs. The objectives of my study were to: determine the population size and apparent survival of free-roaming cats in areas managed by a TNR program, determine population size and apparent survival of free-roaming cats in areas not managed by a TNR program, and compare the population sizes of TNR managed populations to those of unmanaged cat populations. Between September 2011 and September 2012, free-roaming cats were trapped and marked at two sites managed by a TNR program, and at two unmanaged sites. Population estimates indicated seasonal population changes in the unmanaged sites as well as TNR site 1, but not TNR site 2. TNR site 1 had a lower proportion of neuter cats ( < 50% neutered) while TNR site 2 had a much higher proportion of neutered individuals (~90% neutered). Population estimates of the unmanaged sites and TNR site 1 increased in the spring and decreased through the winter months. Population estimates for TNR site 2 remained constant throughout the year. This study showed TNR programs will need to maintain a high proportion of neutered individuals to prevent population increases and that a highly neutered colony is managed for a seasonally stable population of cats as opposed to a decreasing population.


Dr. Elmer J. Finck

Date of Award

Spring 2018

Document Type



© The Author(s)


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