By Pat Dray
The Garden Spot
Pat Dray
So much is said about invasive plants that I sometimes forget to think about invasive species more broadly. An invasive species is an organism that is not indigenous, or native, to a particular area. Since they typically have few or no native predators and reproduce quickly, invasive species can cause great economic and environmental harm to the new area. According to the National Wildlife Federation, about 42 percent of endangered species are at risk due to invasive species.
Surprisingly, one of the most invasive species is the domestic cat. So many of us love the domestic cat, but it does not occur in “the wild” and it’s a major threat to birds. Introduced to the US with European colonists in the 1700s, the number of domestic cats has tripled in the past 40 years.
Although pet cats that are kept indoors do not cause problems, many cats are allowed to roam freely outdoors or are abandoned every year and wind up creating colonies of feral cats. These “free-ranging cats” may look like your pet cat, but they may scratch or bite if approached.
Free-ranging cats have significant impacts on natural environments. They have been shown to reduce native small mammal, reptile and invertebrate populations, and are a major contributor to the decline of bird populations. In fact, cats have been a major contributor to the extinction of several mammal, reptile and bird species.
Today, more than 100 million feral and outdoor cats exist as an invasive species with enormous impacts. Every year in the US, cats kill well over 1 billion birds. The American Bird Conservancy has identified already-declining species like the least tern and wood thrush that are severely impacted by cat predators. It’s estimated that a single feral cat will also kill more than 200 mammals a year – in our suburban area, that’s mainly native mice, shrews, voles, squirrels and rabbits.
Birds are one of a cat’s top meal choices. As pure carnivores they require meat and are always on the prowl for prey. It’s their nature to hunt and this is not going to change. According to a new study published by Nature Communications, more than 2,000 species have been victim to feral cats, with 350 of these species of conservation concern and several already extinct. Free roaming cats also have a tremendous impact on reptiles and amphibians and have even preyed on green sea turtles and cattle.
So, simple solution: keep your cats indoors. If you are aware of feral cats, reach out to your local animal care group such as the New Haven Cat Project (gnhcp.org) for assistance with trap-neuter/spay-release. Place your bird feeders in a somewhat open area so that cats do not have a place to hide and stalk the birds. You can hang the feeder but aim for it to be about five feet off the ground. Ground-feeding birds, like sparrows and doves, can be an easier target for the cat. So instead of spreading food on the ground, spread it on a raised platform that forces a cat to jump up to attack, giving birds a fraction of a second to make their escape.
Pat Dray is a past president of the Garden Club of Orange and a master gardener.