So what's the big deal about free-ranging cats?
The term free-ranging cats (Felis catus) includes feral, semi-feral, and outdoor cats.
Cat colonies have become an overlooked staple in ecosystems worldwide. Many individuals are oblivious to the true impact that this species has on their environments. Of these impacts, first, cats cause fear effects that disrupt their prey's behaviors and suppress wildlife reproduction. Secondly, cats carry and transmit a host of diseases that harm both wildlife and humans including rabies, toxoplasmosis, and plague. Finally, cats kill an average of 1-4 billion birds and 6-22 billion mammals each year in the United States alone. As of 2016, cats were responsible for the extinction of 63 species globally. This makes cats the single greatest source of anthropogenic wildlife mortality. Because of this, it is essential that cat populations be controlled if we want to preserve our already fragile ecosystems.
Cat colonies have become an overlooked staple in ecosystems worldwide. Many individuals are oblivious to the true impact that this species has on their environments. Of these impacts, first, cats cause fear effects that disrupt their prey's behaviors and suppress wildlife reproduction. Secondly, cats carry and transmit a host of diseases that harm both wildlife and humans including rabies, toxoplasmosis, and plague. Finally, cats kill an average of 1-4 billion birds and 6-22 billion mammals each year in the United States alone. As of 2016, cats were responsible for the extinction of 63 species globally. This makes cats the single greatest source of anthropogenic wildlife mortality. Because of this, it is essential that cat populations be controlled if we want to preserve our already fragile ecosystems.
What is Trap-Neuter-Return (TNR)?
The most popular way that cat populations are decreased is through a program known as Trap-Neuter-Return (TNR). Through this program, cats are trapped, sterilized, then released into the area in which they were originally caught. In 2013, a TNR program was established in Stillwater, OK known as "Operation Catnip". Cats that go through this TNR program are marked by removing the tip of their left ear; this is known as the cat being tipped.
Have TNR programs effectively managed cat populations?
TNR has been widely utilized to manage cat populations worldwide, despite very little scientific evidence supporting its effectiveness in decreasing cat populations in a reasonable timeframe. Therefore, we wondered if Operation Catnip, by acting as a traditional TNR program representative, was really functioning at the 71-94% sterilization rate required to actually decrease a cat population.
TNR alone is not be able to effectively decrease cat populations:
We saw a decrease in the mean and range of abundance of cats per location, as seen in figure three, and an increase in tipped cats at an estimated average of 5.4% per year. However, these changes to the population dynamics were found to be statistically insignificant.
The surprisingly low sterilization rate and lack of significant decreases in the population following five years of an active TNR program further bolsters a growing body of literature showing that, despite popularity among politicians and citizens, TNR alone is an ineffective method of cat management.
Free-ranging cats are a monumental threat to native wildlife, not only in Oklahoma, but all over the world. If we want to preserve the delicate ecosystems around us we need to continue to explore methods of controlling cat populations because we cannot rely solely on TNR programs.
The surprisingly low sterilization rate and lack of significant decreases in the population following five years of an active TNR program further bolsters a growing body of literature showing that, despite popularity among politicians and citizens, TNR alone is an ineffective method of cat management.
Free-ranging cats are a monumental threat to native wildlife, not only in Oklahoma, but all over the world. If we want to preserve the delicate ecosystems around us we need to continue to explore methods of controlling cat populations because we cannot rely solely on TNR programs.