For the last 50 years, conservationists have been successful in restoring some of North America’s most iconic avian species from extinction, including bald eagles, wild turkeys, white pelicans, peregrine falcons, Kirtland’s warblers, and California condors.
While we were busy restoring many of the near-extinct birds, a quiet and “largely overlooked” crisis was occurring right before our eyes, yet no one noticed, according to a new study published September 19 in the journal Science.
The bird population in Canada and the U.S. remained relatively stable at about 10.1 billion birds – and should have continued as such, based on counts of breeding adult birds. Instead, it has dropped by 2.9 billion, or 29 percent, according to the new analysis by Cornell University researchers, reports CTV News Canada.
In an attempt to reconstruct the bird population in North America from 1970 to 2017, the research team compiled data from academic studies, along with professional breeding bird surveys conducted by the USGS and Canadian Wildlife Service, along with citizen-science data collected from the Audubon’s annual Christmas Bird Count, the Manomet’s yearly shorebird survey, and other efforts.
Data collected from 143 NEXRAD weather radar stations located across the continent was also used. The NEXRAD stations are used to track entire avian populations during migrations each fall and spring.
“It’s death by a thousand cuts”
“People need to pay attention to the birds around them because they are slowly disappearing,” said study lead author Kenneth Rosenberg, a Cornell University conservation scientist, according to the Associated Press. “One of the scary things about the results is that it is happening right under our eyes. We might not even notice it until it’s too late.”
“It’s death by a thousand cuts,” Rosenberg said in an interview with CTV News. “A lot of this loss is associated with changes in land use for agriculture. This is something we’re seeing around the world. Creating more and more hostile environments in places that used to support quite a few birds.”
“This is a landmark paper. It’s put numbers to everyone’s fears about what’s going on,” said Joel Cracraft, curator-in-charge for ornithology of the American Museum of Natural History, who wasn’t part of the study. “It’s even starker than what many of us might have guessed,” Cracraft said.
The canary in the coal mine
Earlier this year, Digital Journal reported on the first comprehensive report issued by the United Nations on biodiversity in which it said extinction threatens more than 1 million species of plants and animals. Close to 25 percent of birds around the globe live in habitats already affected by climate change, the report said.
Some of the drivers leading to habitat loss and a hostile environment include deforestation, agricultural practices like pesticide use, climate change; pollution; and invasive alien species. Birds play a major role in the food chain and contribute to pest control, seed dispersal and pollination.
“It’s difficult to measure, but the loss of abundance is causing other things to happen than the loss of a species perhaps,” Rosenberg said. “People who care about birds and nature and who are not hunters, it’s time for that very large group of people to pay attention, to raise their voices, to try to affect change in society and politically,” he said.
Keep in mind that right now, this new report is not about the extinction of North American bird species, it is about the “loss of abundance,” according to the analysis. We are going to need to focus on the avian species we commonly see in our backyards, too.
“It’s still important to focus on threatened species, but those tend to be rare species that a lot of people are not very familiar with,” said Rosenberg. “If we can’t sustain populations of birds like starlings and house sparrows, then that is the ‘canary in the coal mine’ indicator.”
Margaret Rubegae, the University of Connecticut’s state ornithologist, gets calls from people every year noticing fewer birds – and she says the new study highlights the problem, according to the Associated Press.
“If you came out of your house one morning and noticed that a third of all the houses in your neighborhood were empty, you’d rightly conclude that something threatening was going on,” Rubega said in an email. “3 billion of our neighbors, the ones who eat the bugs that destroy our food plants and carry diseases like equine encephalitis, are gone. I think we all ought to think that’s threatening.”
