Domestic cats are considered deadly invasive species


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The International Union for Conservation of Nature considers cats to be one of the world’s worst invasive species.


Many news reports point out that our ecosystems are being attacked by Burmese pythons and Asian carps. This leads people to conclude that it is the less charismatic wildlife such as reptiles and fish that are the most threatening of invasive species.

Proposed amendments to the Lacey Act passed by the U.S. House of Representatives on February 4 continue this narrative, with a proposed ban on all exotic animal species crossing state lines.

But an animal that the International Union for Conservation of Nature calls one of the world’s worst invasive species is also one of America’s most popular: Felis catus, the house cat.

For the record, I love cats. My saved daughter, Drama Queen, is one of the greatest joys of my life. However, I am a firm believer that she belongs indoors for her own safety, the safety of other animals, and the general well-being of my suburban environment. I don’t shame anyone who gives access to their cats outside. I just want to make the case that cats are a very important invasive species that pose an arguably greater threat than any other pet, including reptiles and amphibians.

Two of the most obvious and significant impacts that invasive species can have on an ecosystem include increased disease transmission and predation on native species. Outdoor cats can have these effects. In 2014, cats accounted for 61% of rabies cases in domestic animals.

Cats are also responsible for transmitting toxoplasmosis, a fecal parasite that can cause illness and death in wild animals as well as potentially producing birth defects, behavioral disorders or other consequences for people whose immunity is compromised. Most of these diseases are transmitted by outdoor cats, especially those that are not vaccinated, not by cats kept and cared for safely in a secure environment.

Cats are born hunters. Even a well-fed cat will continue to hunt given the chance. Each year, feral cats kill up to nearly 4 billion birds and up to nearly 22 billion mammals, researchers say. This affects not only predation victims such as grackles and sparrows, among many other birds, but also endangered species such as the Florida panther, which face increased competition and exposure to diseases.

But what about trap-sterilization-release? Capturing males humanely, neutering them, and releasing them into the environment should reduce feral cat populations and prevent them from growing, right? Unfortunately no. There is no significant or reliable evidence to suggest that such programs have been successful in significantly reducing outdoor cat populations.

It is even feared that this practice is counterproductive and may encourage cats to be abandoned, assuming they will be happier outdoors and cause no harm. Just because a cat can’t reproduce doesn’t mean it can’t spend years preying on native animal populations or competing with other native species while spreading disease.

The preservation of all species is important. The Lacey Act as a whole and the amendments currently being proposed have good intentions when it comes to environmental management. However, the amendments to the bill miss the mark by attempting to clamp down on the ownership of reptiles, amphibians, fish and other animals, while ignoring the arguably larger problem of outdoor cats.

Although the COMPETES Act with Lacey Act amendments originally passed the House, it is being merged with another bill, the US Innovation and Competition Act. This merger opens the possibility of a reconciliation of these amendments before passing again to Congress. Now is the time to write to state officials and senators asking for a review – a review that ideally could focus on addressing environmental issues without threatening pet ownership by so many. and families.

Luke Guzelis, who trained as a zookeeper at the Brookfield Zoo near Chicago, is earning a master’s degree in biology with a focus on conservation at the University of Miami in Ohio.

© 2022 Chicago Tribune


This story was originally published May 19, 2022 4:43 p.m.


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