In a recent issue of the journal Science (Vol. 365, Issue 6459), there is an article by Elizabeth Pennisi reporting on a recent study showing a steep decline of common birds in North America.
The study looked at bird counts from the 1970s, including the North American Breeding Bird Survey, the Audubon Christmas Bird Count, and the International Shorebird Survey. Aerial surveys over water, swamps and marshes were included.
The study covered 529 bird species, which is about three-quarters of all species in North America, and almost 90% of the bird population. The results indicate a loss of 3 billion birds over the time period.
This is also happening to the more common species, including sparrows, warblers, finches, and blackbirds. There is a chart showing losses per habitat, and the hardest hit were grassland birds, with a drop of 53%.
There are some bright spots. Waterfowl and raptor populations have increased over the same time period. I am including a link to the article from Science magazine and a link to the Cornell Lab of Ornithology, which includes a link to the full scientific study.
I find the study very concerning. I have written about the decline in the monarch butterfly and decline in pollinator species; there have been reports on the decline in amphibians; and now we have a study showing a dramatic decline in birds. What is happening?
While we understand some of the root causes, like habitat destruction affecting wildlife populations, why are we seeing declines in birds that have adapted to urban landscapes?
Hopefully this will result in studies to more accurately identify the causes. The Cornell website gives some action items individuals can do to help bird populations.
I sincerely hope this will be a wakeup call to everyone on the effect we are having on our ecosystem, since we rely on it for our survival as well.