Birds throughout the US have adopted a disturbing habit that could have devastating implications for human society if it continues.
Researchers have found that birds are abandoning their usual migration patterns, with warmer temperatures in their winter habitats disrupting their annual flights
While delaying their yearly flight south may not sound like a major problem, a visiting scientist at Cornell University, Andrew Farnsworth, warned that it could lead to many bird species dying out and drastically altering nature.
Birds play an important role for people because they help control pests, spread seeds, and pollinate plants.
Roughly five percent of the plants used for food and medicine by humans rely on birds to pollinate them.
If more birds die out because they struggle to find food when the seasons change, food production drops and the balance of nature is disrupted.
Farnsworth, a migration ecologist, revealed that rising temperatures in places like the Arctic and northern forests, along with issues like wildfires, are making it harder for birds to survive.
Overall, the National Audubon Society has warned that 389 North American bird species will become vulnerable to extinction within the next 50 years.
Audubon, a nonprofit organization in the US dedicated to protecting birds and their habitats, noted that those 389 species represent nearly two-thirds of the species they studied.
Researchers warned that these birds were at risk of losing more than half of their habitats by the year 2080.
A study by the Cornell Lab of Ornithology revealed that approximately three billion birds in North America have been lost since 1970.
When birds die off en masse, it quickly impacts the pollination of tropical plants, such as bananas, coffee, and cacao, which produce chocolate.
Medicinal plants, such as those used in traditional remedies or pharmaceuticals, including orchids or aloe species, may also decline, limiting access to natural treatments.
If bird populations continue to decline, farmers may face challenges growing enough food, which could increase costs and affect food availability worldwide.
The main driver of this mass extinction event was found to be birds losing their living spaces, worsened by climate change, pesticides, and other human-related impacts like urban development and window collisions.
‘There’s this very close relationship between where birds are when on the planet and what’s happening with the climate and what’s happening with weather,’ Farnsworth told NBC Connecticut.
Rising global temperatures have changed the timing of seasons, causing birds in warming regions to leave their nests earlier or later than usual.
This can mean they arrive at breeding or feeding grounds before food like insects or plants is available.
Birds can end up starving, not finding suitable shelter, and struggling to find a mate, leading to smaller and smaller populations as less birds survive the winter.
Several species in the US have already been affected by this changing behavior, including the Black-throated Blue Warbler, Red Knot, and Swainson’s Thrush.
Researchers with Audubon found that Black-throated Blue Warblers have seen their populations drop off in the US due to climate-driven mismatches that have left the birds with less food when they migrate from North America to the Caribbean.
Red Knots, a shorebird that lands in the US during its migration from the Arctic to South America, have seen their populations decline by around 75 percent.
The Cornell Lab found that warming Arctic temperatures have disrupted their breeding grounds, while rising sea levels have shrunk their coastal feeding sites.
Meanwhile, the Swainson’s Thrush, which migrates from breeding grounds in Canada and Alaska to wintering areas in Central and South America, has been dying out due to climate-driven habitat loss from wildfires and warming forests
This has destroyed their nesting and stopover sites in California, Oregon, Washington, New York, Maine, and Colorado.
‘We do see birds track climate change, obviously some are managing to do it, but the challenge is for those that can’t,’ Farnsworth explained.
Researchers have noted that people who feed birds make the problem even worse, making them less incentivized to leave and by attracting predators that attack birds who stay.
