Birds be safe: Can a novel cat collar reduce avian mortality by domestic cats (Felis catus)?

• We tested the use of a novel cat collar in reducing bird and mammal mortality.
• Cats wearing collars killed 19 times fewer birds than uncollared cats.
• The Birdsbesafe® collar is highly effective at reducing bird deaths.
• We strongly suggest its use for owned and feral cats, primarily in the spring.
• The Birdsbesafe® collar is an effective conservation tool for use on domestic cats.

The domestic cat (Felis catus) has been described as the largest anthropogenic threat to songbird populations in North America. We examined the effectiveness of a novel cat collar in reducing avian and small mammal mortality by cats. The 2-inch wide Birdsbesafe® collar cover (CC) is worn over a nylon quick-release collar, and the bright colors and patterns of the CC are hypothesized to warn birds of approaching cats. We conducted two seasonal trials, each lasting 12 weeks, in autumn 2013 (n=54n=54 cats) and spring 2014 (n=19n=19 cats). Cats were randomly assigned to two groups, and CCs with interior collars were removed or put on every two weeks, to control for weather fluctuations and seasonal change. Cats wearing Birdsbesafe® CCs killed 19 times fewer birds than uncollared cats in the spring trial, and 3.4 times fewer birds in the fall. Birdsbesafe® CCs were extremely effective at reducing predation on birds. Small mammal data were less clear, but did decrease predation by half in the fall. The Birdsbesafe® CC is a highly effective device for decreasing bird predation, especially in the spring season. We suggest that the CCs be used as a conservation tool for owned as well as feral cats.