Regularly I get emails asking why there are fewer birds in one’s backyard this year, or why there are fewer blackbirds, or why hummingbirds are not coming to their feeders, or something like that. The answer is complicated.
First of all, there are about 3 billion fewer breeding birds in the U.S. and Canada since 1970. This was based on a study of 529 bird species in 2019, published in Science. That’s a lot of birds, about 30 percent of the entire North American population outside of Mexico. The greatest losses were among grassland birds which declined by 53%, or 700 million birds, including 92 million Red-winged Blackbirds. There are numerous reasons- windows, cats, habitat destruction, climate change, and pesticides are the biggest culprits, but there are lots of other possible reasons for local declines in one’s backyard.
Has anything changed in or around your house? Did your neighbors get a new cat or dog? Was a new house or addition built on the other side of your fence? Did you hire a new lawn service that might be applying pesticides? Did you change any landscaping – remove shrubs, take down trees, or move your flower garden? Is there more traffic noise in your neighborhood? Have the teenagers next door gotten even noisier? Have you changed the food in your bird feeder? See any signs of raccoons or rats? A hawk might have taken up residence in your neighborhood. And so on. It could just be your local environment.
On a greater scale, what about the weather? Has it been unusual for this time of year? Exceptionally hot or cold or windy or other unusual weather conditions that have been happening lately. How about the food supply? Berries, insects, seeds, and other food items fluctuate and birds move along with these food sources. There may be less food in your yard this year or just more abundant food elsewhere.
Diseases may also play a part – conjunctivitis, West Nile Virus, avian cholera, malaria, and other afflictions may reduce certain bird populations.
Or, you just may be misinterpreting things. Do you know for sure there are fewer juncos at your bird feeder or do you just think so? It is a good idea to keep records and a good way to do that is on eBird which is an online database of bird observations providing researchers and amateur naturalists with real-time data about bird distribution and abundance. Or, a simpler way to go might be FeederWatch, a project that encourages you to watch the birds at your feeder and submit the results along with 4000 others to generate a national database to help monitor bird populations. Participants receive the FeederWatch Handbook and Winter Bird Highlights, and annual summary of FeederWatch observations across the country. Or, simplest of all, sit on your patio or in your kitchen window and take notes every day at about the same time. Of course, you’ll need to do it for a few years before a pattern or trend emerges. But it’s a nice chore.
Finally, you might wish to consult The Cornell Lab of Ornithology’s Seven Simple Actions to Help Birds.