A new report has found that nearly two-thirds of America’s breeding bird species were moderately to highly vulnerable to the effects of climate change.
Earth is warming, storms are getting stronger, native habitats are disappearing, and it’s mostly the work of humans. We already know that the US has lost nearly 30 per cent of its birds in the past 50 years, and this new report from the National Audubon Society presents further evidence that if people don’t act, things will get worse.
The report considers the many effects climate change might have, starting with a projected 1.5 to 3 degree Celsius rise in global temperature. That in turn would unleash a wave of impacts that are bad for birds (and people) including sea level rise and lake level change, cropland expansion, more extreme weather events, more fire, and urbanisation. These numbers were used to project the future range of America’s breeding bird species (that is species that breed anywhere north of Mexico), and then calculate the percentage of the birds’ range that would be affected by these threats.
The report found that 97 per cent of the country’s breeding birds would be impacted by two or more climate-related threats, mostly extreme heat in the spring as well as fire. In total, the projections found that 389 breeding bird species were fell into the moderate or highly vulnerable range, based on the calculated percentages. This included all of the arctic-breeding species, all but one of the boreal forest-breeding species, and 86 percent of the western forest breeding species, and 78 percent of waterbirds.
“The three billion bird loss was mostly driven by habitat loss, invasive species, and pesticides,” said Mike Parr, president of the American Bird Conservancy who was not involved in this study. “Going forward, climate is likely to be a top threat, if not the top threat, to birds.”
He reminded us that birds are a good indicator to environmental health overall, given that they’re everywhere, they’re very sensitive to ecosystem changes, and there is a large, dedicated group of hobby birdwatchers who monitor bird populations.
At risk from four or more climate change-induced threats are some especially well-known and popular birds such as the brown pelican, wood thrush, scarlet tanager, and piping plover.
Audubon released a report in 2014 that determined nearly half of North American birds were sensitive to climate change’s effects. This new report includes updated scientific analysis that takes each bird’s biology into account.
Indeed, the situation is dire for birds across the Atlantic. Just last month, a team of ornithologists determined that America's birds were dying at an alarming rate from human-induced causes. Some criticised that report for lumping all of the birds together, which may have skewed the data by including drastic losses from invasive species like house sparrows and European starlings, and citing that the populations of some endangered species, like the California condor and the Kirtland’s warbler, have recovered, somewhat. However, this new report solidifies that even for recovering birds, very real threats still exist.
As with all projections, the saying goes that all models are wrong, but some are useful – we don’t know for sure how the effects of climate change will pan out across the United States. But scientists are in consensus that the Earth is warming due to human activities, and naturally our wildlife will suffer from drastic changes to the habitats they rely on.
Things are dire, but not hopeless. This report confirms the Intergovernmental Panel on Climate Change’s report that the world’s population must work to reduce our greenhouse gas emissions by 45 percent below 2010 levels before 2030, and reach net-zero carbon emissions by 2050, to limit warming to 1.5 degrees Celsius. But there’s more than just emissions we must deal with – we must push our governments to protect our coastlines, forests, wetlands, and grasslands for the future of humans as well as the animals we share these habitats with.
Featured image: Ryan F. Mandelbaum