“A 2013 study by the Smithsonian’s Migratory Bird Center and the U.S. Fish and Wildlife Service concluded that cats kill up to 3.7 billion birds and 20.7 billion small mammals annually in the United States.” [Kerry Lauerman, Washington Post September 2, 2016]

Learn more about the problem of free roaming cats and birds:

There are two approaches to protecting birds and animals from free-roaming cats.
One is trap and euthanize, which is not politically palatable. Another approach is controlled trap, neuter and release (TNR), which at least does reduce the population growth from fertile abandoned, stray, and feral cats, but it is not condoned by top environmental organizations including The American Bird Conservancy, the Cornell Lab of Ornithology, and the Wildlife Society, which oppose TNR as both inhumane treatment of cats and too great a risk to wildlife.* Furthermore, the Humane Society of the United States only condones Trap Neuter Return Maintain (TNRM), which means the cats are not simply released, but are returned to a colony area which has a caretaker ensuring they have access to food, water, and shelter. The idea being, cats are territorial and a limited number of neutered feral cats will hunt fewer birds than cats that can reproduce every few weeks. Unfortunately this approach is also associated with colony diseases which sometimes result in mass euthanization programs.

The best use of limited resources is to assist with spay/neuter programs for owned cats.**
Cats can begin reproducing by the age of four months, with four to five litters in a season. To this end, the Bridgerland Audubon Society has assisted in a Feline Fix Fundraiser campaign for the Cache Humane Society, supporting free spay/neuter programs.

Additional Resources
Cats Indoors, American Bird Conservancy, https://abcbirds.org/program/cats-indoors/
Inspired by these awesome cat guardians? Take the pledge and join this community of caring cat owners to keep both cats and wildlife safe. https://abcbirds.org/action/cats-pledge

Terry Messmer, Utah State University Extension wildlife specialist, Feral Cats a Cause for Concern, USU Extension, https://extension.usu.edu/archive/feral-cats-a-cause-for-concern/

Our Pandemic Project: 2020/2021 Cache Humane Society Feline Fix Project https://bridgerlandaudubon.org/cache-humane-society-feline-fix-fundraiser/

The Wildlife Society has the most comprehensive anti-TNR statement:
The Wildlife Society, Final Position Statement, Feral and Free-Ranging Domestic Cats, https://wildlife.org/wp-content/uploads/2014/05/28-Feral-Free-Ranging-Cats.pdf

Feral Cats: Impacts of an Invasive Species, https://wildlife.org/wp-content/uploads/2014/05/Feral-Cats.pdf

Study Finds Feral Cats Likely Driving Disease Among Deer, https://wildlife.org/feral-cats-likely-driving-disease-among-deer-study-finds/

The American Bird Conservancy: https://abcbirds.org/?s=TNR

FAQ: Outdoor Cats And Their Effects On Birds, All About Birds, The Cornell Lab of Ornithology, https://www.allaboutbirds.org/news/faq-outdoor-cats-and-their-effects-on-birds/

Organizations which support TNR include the Humane Society of the US (HSUS, with caveat: a colony caretaker), Best Friends Animal Society, and Alley Cat Allies.

Humane Society of the US, which is not opposed if TNRM is done properly (i.e. with a colony caretaker providing food, water, and shelter, which has not been the local practice):
“The Humane Society of the United States supports and promotes robust trap-neuter-return and similar sterilization programs as effective and humane means to address already existing populations of cats in our communities. Reducing the number of cats on the landscape also reduces threats to birds and other wildlife. The HSUS believes that the humane reduction and eventual elimination of unowned cat populations should be the end goal for all TNR participants and supporters. ”
https://www.humanesociety.org/resources/our-position-cats

Best Friends Animal Society TNR FAQ:
https://resources.bestfriends.org/article/frequently-asked-questions-about-tnr

How cat advocates can allocate time and other resources for the biggest impact
Bays, Danielle Jo, Animal Sheltering magazine, Humane Society of the US, Winter 2018-2019, https://humanepro.org/magazine/articles/pointing-way-pyramid
Inspired by diagrams for healthy diets, the community cat pyramid encourages a holistic approach to cat management and a strategic use of resources.
Graphic by Patrick Ormsby/The Humane Society of the United States

Domestic Cat Predation on Birds and Other Wildlife
https://abcbirds.org/wp-content/uploads/2015/05/CatPredation2011.pdf

The Problem of Predation of Songbirds and other wildlife:
National Geographic, Smithsonian Institution, and U.S. Fish and Wildlife Service:
[…]
How beloved pets become invasive predators – an interview with Dr. Peter Marra, National Geographic Society, June 6, 2017, https://blog.nationalgeographic.org/2017/06/06/how-beloved-pets-become-invasive-predators-an-interview-with-dr-peter-marra/

Seven Simple Actions to Help Birds, Smithsonian’s National Zoo & Conservation Biology Institute, https://nationalzoo.si.edu/migratory-birds/seven-simple-actions-help-birds

Rosenthal, Elisabeth, Tweety Was Right: Cats Are a Bird’s No. 1 Enemy, March 20, 2011, https://www.nytimes.com/2011/03/21/science/21birds.html

Threats to Birds, Migratory Bird Program, US Fish and Wildlife Service(FWS), US Department of the Interior(DOI), last updated September 14, 2018, https://www.fws.gov/birds/bird-enthusiasts/threats-to-birds.php

Dutcher, Alex et. al. Free-ranging and Feral Cats, Wildlife Damage Management Technical Series, USGS, October 2021, https://www.aphis.usda.gov/wildlife_damage/reports/Wildlife%20Damage%20Management%20Technical%20Series/free-ranging-and-feral-cats.pdf

Martyn, Monika, How Many Birds Do Cats Kill: The Silent Toll on Our Feathered Friends, WorldAnimalFoundation.org, October 12, 2023, https://worldanimalfoundation.org/advocate/how-many-birds-do-cats-kill/

Lauerman, Kerry, Cats are bird killers. These animal experts let theirs outside anyway. Washington Post, September 2, 2016, https://www.washingtonpost.com/news/animalia/wp/2016/09/02/cats-are-bird-killers-these-animal-experts-let-theirs-outside-anyway/