Thousands of migrating bird species are literally falling from the sky – dead. The race is on to find out why.
Ornithologists are desperate to uncover the reasons behind the bizarre deaths of countless bird species that have inexplicably perished in south-western United States (US). The majority are long-distance migrants such as finches, flycatchers, swallows, warblers, and bluebirds.
Described as a “national tragedy”, experts believe the mass die-off is likely related to the climate crisis – exactly how remains unknown.
The corpses of birds have been found across New Mexico, Colorado, Texas, Arizona, and farther north into Nebraska, with growing concerns there could be hundreds of thousands dead elsewhere.
It’s not uncommon for some birds to die during their autumn migration, but not in these numbers and certainly not plummeting out of the sky in droves.
The first deaths were reported last month, on August 20, on White Sands Missile Range in New Mexico. At first, it was thought to be an isolated incident but after monitoring online forums, ornithologists noticed “bird drops” were happening across the region.
According to Martha Desmond, a professor in the biology department at New Mexico State University (NMSU), many carcasses are “scrawny”, with little remaining fat reserves or muscle mass – just feathers and bones. Some appeared to have nose-dived into the ground mid-flight.
Numerous theories are doing their rounds as to why these birds are dying but nothing has yet been confirmed as concrete. The drought brought on by the climate crisis could be related. The drier climate means there could be fewer insects – the main food source for migrating birds.
Another theory is that the smoke from the wildfires may have damaged their lungs. Large amounts of smoke have drifted across the country on easterly breezes. We know that exposure to smoke can lead to immunosuppression, respiratory distress, and other severe health problems for birds.
Reports suggest some birds have been displaying unusual behavior before dying, like not eating, sleepily drifting low to the ground, and searching the ground for bugs to eat rather than sticking to their usual trees and shrubs. Many birds observed appeared emaciated.
Carcasses are being sent to the United States Fish and Wildlife Service (USFWS) forensics laboratory in Oregon and National Wildlife Health Centre (NWHC) in Wisconsin for testing, which is expected to take at least two weeks. Scientists are urging people in the area to log any sightings of dead birds on the citizen science website (https://www.inaturalist.org/projects/southwest-avian-mortality-project).
“Mass die-offs of any species is extremely alarming and has a butterfly effect on the planet,” said David Barritt of Network for Animals (NFA).
“Birds play a key role in the functioning of the world’s ecosystems in a way that directly impacts human health, economy and food production – as well as millions of other species. Following the United Nations (UN) report showing world leaders have failed to meet a single conservation goal set in 2010, it’s clear that Mother Nature is desperately trying to tell us something – and it’s not that all is okay on the planet.”
Features image credited to: Allison Salas – New Mexico State University
