On a recent annual birding trip to Monhegan Island, a friend of mine was fortunate early in the day to see a stunning male scarlet tanager (Piranga olivacea), an infrequent Neotropical migrant to Maine. My friend spent the rest of the day exploring the island and recording sightings of migratory and resident birds. As he walked toward the ferry to go home, a large tabby cat stepped into his path, carrying in its mouth a male scarlet tanager.

This story is repeated throughout the world, with different cats and different birds in the same predator-prey relationship anywhere domestic house cats are allowed to roam freely or their cousins have gone feral and live, feed and reproduce outdoors. For those of us who love birds and our feline pets, it is time to limit this destructive impact on birds and other animals in the wild.

The International Union for Conservation of Nature has put the domestic cat on the top 100 list of global invasive species. Our tabby now shares this list with the brown tree snake, kudzu, fire ants, lionfish, Burmese pythons and other nefarious organisms that are outside their native range.

Most reputable organizations put the number of house cats in the U.S. at about 100 million, and it is thought that another 50 million to 70 million feral cats are living in the wild. The 150 million to 170 million number of cats in America exceeds the totals for cattle, pigs, sheep and goats combined. The wild bird population in the U.S. is somewhere between 20 billion to 25 billion; of that total, cats are thought to kill around 2 billion to 3 billion annually. This tragic number is greater than all of the next four most lethal human-related causes combined. That includes collision with building glass (599 million), which killed the yellow warbler in our backyard; collision with vehicles (215 million); poison (72 million), and collision with electric lines (25 million). That at least one out of every 10 living birds in the U.S. will be killed by a cat each year is a chilling reality.

The solutions to this issue are numerous, and some ideas have led to advocates losing their jobs or being subject to public ridicule, hate mail and even death threats. Nongovernmental organizations like Alley Cat Allies and Best Friends Animal Society campaign against lethal control of feral or free-ranging house cats and promote the idea of trap, neuter and release as the primary solution to reducing cats’ impact on wild birds. Trap, neuter and release has been well debated, but its math simply does not allow for enough of a reduction in the feral and free-ranging cat populations to make a significant difference.

The high cost of trap, neuter and release is part of the issue, as is the overall actual reduction of a feral population that continues to have new arrivals. There is evidence that population reductions can be realized if the trap and neuter program is linked to a robust adoption program instead of releasing the spayed or neutered cats back into the wild.

So what can be done? A simple first step here in Maine would be for legislators to change our animal trespass laws to include cats, which they alarmingly do not. Why not require that cats be licensed and wear a collar that has their license and vaccination information on it? We require our dogs to be registered and properly vaccinated. Why not our cats?

Don’t let your cat(s) outside. Even a neutered cat is still a bird-killing machine. If you have a bird feeder and enjoy watching birds come to it, you are baiting these birds to their death if your house cat or your neighbor’s house cat is let outside. Stop feeding and caring for feral cats. Consider creating an outdoor cat enclosure for your tabby that’s connected to your house or apartment. For newly adopted kittens, keep them indoors and they will quickly become accustomed to an indoor life and not want to go outside.