Anyone who has had cats that spend time outside has likely experienced it: coming home from work to find feathers at the front door. Or stepping onto the back patio and crunching a squirrel tail underfoot. Or working in the yard and discovering a dead mouse or mole.

Cats can be killers — some better than others — and Abby Powell wants them.

Powell is a research biologist for the Florida Cooperative Fish and Wildlife Research Unit of the U.S. Geological Survey and a courtesy professor in wildlife ecology and conservation at the University of Florida.

She is seeking residents who will volunteer their cats that go outdoors for a study to learn if a cloth collar cover — with a color pattern that wouldn’t ordinarily be seen in nature — alerts birds, mammals and even reptiles that a predator is in proximity.

If it does, the collar could end up saving the lives of millions of birds and other wildlife, if not calming the often vitriolic debate over outdoor cats.

“The idea is that most birds, and reptiles too, are very visual and clued into colors. If they see something like that, it alerts them — it’s something they wouldn’t expect to see, especially if it’s moving,” Powell said. “Not everyone is interested or able to keep their cats inside. This would potentially mitigate some of the damage they can do to wildlife.”

The Birdsbesafe collar, which is available commercially, has been studied in Australia and in upstate New York. Powell said her study will be an extension of the New York testing to learn its effectiveness in the South, where birds have a longer breeding season.

One of the most recent and most cited studies of predation by cats, named in part for Smithsonian researcher Peter Marra, estimates that cats annually kill between 1.3 billion and 4 billion birds in the U.S. and 6.3 billion to 22.3 billion mammals. Most of the killing is by unowned cats.

Marra is an opponent of cat owners allowing their felines to go outside and proposes that unowned cats be trapped and put up for adoption, placed in a sanctuary or euthanized.

The Marra study is based on a review of other studies that estimate predation rates. He contends that owned cats kill a median of more than 1 billion birds a year while unowned cats kill a median of 1.7 billion.

Critics believe the Marra study is flawed because it is based on a wide range of studies from many areas. Critics also contend that unwarranted extrapolation was used to arrive at the estimates.

Cat predation is a divisive issue.

Some believe all owned cats should be kept indoors and unowned cats should be trapped and taken out of the environment, even cats that are fed by people. They believe that anything less leads to the death of birds and other wildlife.

Many cat advocates favor trap-neuter-return programs in which unowned “community cats” are caught, sterilized, vaccinated and returned to the location from which they were caught. They believe it is a humane response to the problems of unwanted cats and help stem their numbers — and thus predation.

Into this debate flies Birdsbesafe — a fabric ring that slips onto a break-away cat collar and resembles a hair scrunchie.

Susan Willson of St. Lawrence University in Canton, New York, was the first to study the collar’s effectiveness in the U.S. and found that it does considerably reduce bird predation. It was tested in fall 2013 and again the following spring. An Australian study also found the collar cut bird deaths.

In the fall Willson found that 3.4 times more birds were killed when the collars were not in use. It was 19 times greater in the spring.

“We suspect these differences may have to do with seasonal changes in bird behavior and/or visibility,” the study states.

Powell said she will conduct a similar study to learn if the collar will alert birds here. She is hoping to get 50 cats — half of which will wear the collar for four weeks and half of which won’t. Owners will collect whatever animal remains they find, including lizards, and freeze them.

At two weeks, the collars will be switched between the two groups. The experiment will run for eight weeks.

Powell needs 50 cats for the study and must find them soon so it can be done in the spring. A reason for doing it in spring is because that is breeding season, when birds are active and distracted.

“Because of the shorter breeding season as you get farther north, the male birds are full of testosterone — they’re singing, displaying, defending their territories. They are really distracted for a short period of time,” Powell said. “Here there is such a long breeding season that they don’t have such a spike in reproductive hormones. Our hypothesis is (the collar) will work well in both places but better the farther north you go.”

Cat owners will get a break-away collar and the Birdsbesafe cover. A group of UF students are helping, including identifying the prey items.

Dr. Julie Levy, founder of the Operation Catnip trap-neuter-return program and a professor at UF’s College of Veterinary Medicine, said she is aware of the promising results of previous studies.

“I hope it proves to be successful because nearly half of pet cats are allowed outdoors, and at least some of them hunt,” Levy said in an email. “If it works, it will give cat owners a practical tool to reduce the impact on wildlife.”

Grant Sizemore, director of the invasive species program for the American Bird Conservancy, said the organization’s position is that all owned cats should be kept indoors. The use of a Birdsbesafe collar could be used for cats that go outside occasionally as they are transitioning to an indoor life.

“Clearly the best way to protect cats and birds is to keep cats inside,” Sizemore said. “Obviously, anything that can reduce the impacts that cats have on wildlife is beneficial but ultimately the goal should be to reduce as much as possible and the best way to do this is to keep cats in.”

Any cat owner who is interested in participating in the study can reach Powell at abbypowell@ufl.edu.

“We just need cats that go outside and kill things. And we need owners who are willing to collect the stuff for us. We need collaboration from the cats and the owners,” Powell said. “It’s such a polarizing issue. This is a scientific study and we are staying completely neutral on the topic. We’re not judging anybody if they have outdoor cats.”