BCAS Position Statement on Feral and Free-Roaming Domestic Cats
Drafted by the BCAS Conservation Committee in February 2025
Approved by BCAS Board on March 20, 2025
Summary: Domestic cats (Felis catus) can make wonderful pets. But cats that roam outdoors can have serious consequences. Across the globe, cats have been introduced into new habitats by people with terrible results. Outdoors, cats – both feral and free-roaming domestic -- are a non-native and invasive species that threaten birds and other wildlife, disrupt ecosystems, and spread diseases. Free roaming cats kill 1.3–4 billion birds and 6.3–22.3 billion mammals each year in the U.S. alone, making cat predation by far the largest source of direct, human-caused mortality to birds. There are many benefits to birds, cats, and people when cats are maintained indoors or under an owner's direct control.
The Problem:
In the United States alone, there are 60 million to 100 million free-ranging, unowned cats. These are non-native predators that, even using conservative estimates, kill 1.3–4 billion birds and 6.3–22.3 billion mammals each year in the U.S. alone. As a conservation organization, the Boulder County Audubon Society recognizes that this is an unnatural situation that is taking a tremendous toll on native wildlife. Because outdoor cats are a human-caused problem, it is our responsibility to find ways to address it.
Many people who care about cats also recognize that it’s not ideal to allow cats to roam. Outdoor cats live short lives characterized by hardship, disease, and injury. Cats suffer when they are hit by cars, injured or killed by predators or other cats, or contract diseases. Outdoor cats also transmit diseases such as toxoplasmosis to humans and to wildlife.
Boulder County Audubon’s position:
We support efforts to educate and encourage cat owners to keep cats indoors or on harness or leashes or in a safe enclosed outdoor structure, and to have their pets spayed or neutered.
We support programs to neuter or spay cats before they reach reproductive age, and to vaccinate and register cats.
We oppose “managed” outdoor cat colonies and Trap-Neuter-Release (TNR) programs unless accompanied by an intensive adoption program, monitoring of feral cat colonies, public education on the need to keep cats indoors, and public involvement in reducing/eliminating cat colonies.
We support the development and implementation of education efforts that foster an understanding of the biological and social impacts of allowing cats to roam outdoors.
We support the development and dissemination of educational information to municipalities, residents, veterinarians, and other stakeholders on the negative impacts of feral cat colonies, including information on the effects on wildlife, disease transmission, and the health risks to cats.
We support the passage and enforcement of state legislation and local ordinances prohibiting the establishment of feral cat colonies and the release of feral or unwanted cats outdoors.
We oppose the passage of state legislation and local ordinances that condone or legalize the deliberate establishment of feral cat colonies.
We encourage research to provide additional insight into the effects that feral and outdoor, unattended domestic cats have on native wildlife populations.
Cited and Additional Resources:
American Bird Conservancy. Cat Invasives. Accessed 20 February 2025. https://abcbirds.org/threat/cats-and-other-invasives/
American Bird Conservancy. Cats Indoors. Accessed 20 February 2025. https://abcbirds.org/program/cats-indoors/cats-and-birds/
American Bird Conservancy. Solutions for Pet Cats. Accessed 20 February 2025. https://abcbirds.org/catio-solutions-cats/
Loss, S.R., T. Will, & P. Marra. 2013. The impact of free-ranging domestic cats on wildlife of the United States. Nature Communications 4 (1396). https://doi.org/10.1038/ncomms2380.
PETA. Why All Cats Should be Indoor Cats. June 25, 2024. https://www.peta.org/living/animal-companions/caring-animal-companions/caring-cats/indoor-cats/
The Wildlife Society. TWS Issue Statement: Feral and Free-ranging Domestic Cats. March 24, 2020. https://wildlife.org/tws-issue-statement-feral-and-free-ranging-domestic-cats/