Big Blue Birdhouse, 10/13/23: Outdoor Cats & Other Killers
Hello and welcome to another of my Friday columns. Today's BBB column is a bit smaller scale, focused on a more tangible topic in the lives of birds and how they intersect with us. I feel that we should all be considerate neighbors to wildlife, and that awareness of our impact on the world around us is a core part of this website. In this vein, I wanted to talk about elements of our day to day lives that threaten wild birds. Of course, diving deep into humankind’s impact on wildlife and our moral imperatives to fix it is far too complex a subject for this column, or likely for my site at all. Some discussion however is necessary.
Earlier this year when I was assisting the St. Paul Audubon Society with their hybrid zoom meetings, there was a discussion about renewable energy. A woman in the room asked about the impacts of wind energy on bird mortality. She claimed that the left’s push for renewable energy on environmental grounds clashed with her love of birds, because she did not want to support structures that kill the creatures she cares about. A man in a nearby row chewed her out for listening to unbalanced, incomplete, and outright misleading information about bird mortality. The two of them later continued their heated conversation at the side of the room once the meeting was complete, and I made the decision to leave promptly without engaging with either one.
In my opinion, the man was ruder than he needed to be with the women. However, he was right. The fear mongering around wind turbines killing birds is vastly overblown and exaggerated in articles that are pushed by fossil fuel backed actors to undermine the push for renewable energy. By taking away the supposed moral high ground of the environmental left, fossil fuel supporters can muddy the discussion about what energy sources are truly better for the planet Earth. I wrote a research paper and gave a presentation on threats to birds when I was studying at the University of Minnesota, primarily focused on agriculture. Using the Fish and Wildlife Service’s 2017 research, I showed how wind energy kills less than 250,000 birds a year, which is a negligible amount next to countless other ways in which we’re out there killing birds. Of particular note for the public debate around renewable energy: air pollution from fossil fuels likely kills far more birds, as permanent lung damage is a common threat to birds living near humans.
Outside of the windmill myth, there is very little public discussion around what specifically kills birds. Of course, there’s plenty of discourse about general environmental damages: pollution, habitat destruction, the changing climate, and more pose as much risk to birds as they do to any other piece of wildlife, and these are key issues for environmentalists. Birds in particular face any number of more narrow threats, however, and I wanted to touch on a few.
Firstly, collision. Birds fly into stuff, hurt themselves, and die. It happens in every American city every single day, and kills millions upon millions of birds a year. Communication towers account for 6.6 million bird deaths a year, electrical lines account for 25.5 million, vehicles account for 215 million, and window glass accounts for a staggering 599 million. All told, manmade structures and objects kill over 800 million birds a year, or more than three thousand times more than windmills, which I withheld from this count because it’s kill count is essentially a rounding error. Even though windmills are more optional for our society than say, communication towers and electrical lines, it still shows the comical hypocrisy with which some people use bird deaths as an easy political prop to knock down something they simply don’t like; anyone who actually thinks wind energy isn’t worth it’s impacts on bird populations should be out there fighting the more important battles instead.
Some people are truly fighting those battles. Many groups have formed to work on making window glass visible to birds, and prevent collision deaths. The skyways in Minneapolis and Saint Paul for example were especially dangerous, so many now have local art designs or simple patterns and illustrations on them. Less sleek? Perhaps. But a valuable trade off. For a fancier or less visually apparent look, bird-visible gradients and dots can be taped onto windows and make them safer for wildlife. My in-laws added some to their new home in California after hearing two different birds slam into glass.
Are all individuals and companies obligated to do this? No, in the same way that we aren’t obligated to exclusively use renewable energy. But in situations where it’s possible, I think it’s an excellent thing to do. Windows make up the majority of collision related deaths, and slapping something on them harms nobody.
If you thought 800 million bird deaths was a truly awful number, though, you might want to sit down.
The biggest killer of wild birds that humans are directly responsible for is not up for debate: it’s cats. The domestic house cat is an invasive species in the United States, and our wildlife is simply not equipped to deal with house cats as predators. Millions of cats live partially or entirely outside: the stray cat population in America is out of control, about as large as the population of actual pet cats, and many more cats are allowed outside by their owners. The FWS’s latest estimate suggests that each year, domestic cats kill 2.4 billion birds. That is over 900 thousand times more than windmills, or triple the amount of all those combined collision deaths.
It’s one thing when stray cats hunt birds for food; it’s unfortunate that an invasive species has become so prevalent in the wild because of our actions, but at least it’s a wild animal surviving. What bothers me more is the outdoor pets hunting for fun. Outdoor cats often bring carcasses back to their owners, play with them, or hide them and never eat them. This accounts for millions of bird deaths, and the stimulation the cats get from it could easily have been replaced by a toy or a laser pointer.
I’m all for window coverings, but I don’t expect them from everybody. I’m all for renewable energy, but I think it’s a big and complicated issue given the scale of our energy grid. Outdoor cats however I feel are almost never a good idea, and that we should care far more about keeping pets inside and about stopping the spread of stray populations. Keeping your cat in the house and spaying and neutering all of your pets is one of the best things you can do for wild bird populations. Domesticated cats do not need fresh air to be happy and healthy, as long as they are given affection and stimulation. In fact, outdoor cats are at a far greater risk of being killed by cars or hawks, becoming diseased, or getting into fights with other wild cats. All told, an outdoor cat has a life span 10-12 years shorter than an indoor peer. If you care about your feline friend, it simply makes no sense to let them wander freely. Even in a controlled backyard, they should always be closely monitored.
Being kind to birds extends far beyond windows and cats, to proper feeder maintenance and our gardens. But I think those are the biggest issues and impact the greatest number of people. I don’t intend to speak for all situations: domesticated cats have historically been used by farmers as a means of pest control, for example, and I don’t intend to tell them what they can or can’t do. However the people I’ve seen defending outdoor cat use have used faulty reasoning and downplayed the negative impacts. If we are going to be considerate with the way we live and try our best to minimize ecological damage, it often starts in our own homes. Thanks for reading.
