A swarm of birds suddenly “fell from the sky” mid-flight and crashed unexplainably to the ground on February 7 in the Mexican town of Cuauthemoc.
A surveillance camera recorded this strange phenomenon that occurred in this city in the state of Chihuahua, in northern Mexico. This video went viral on the networks, going around the world.
According to local media, on the morning of February 7, hundreds of migrating birds from Canada flew quietly over a deserted city street; when suddenly, several dozen of them collapsed dead on the roadway.
The police were called around 8:20 a.m. by residents of the Alvaro Obregon neighborhood to report that many dead birds were strewn on the sidewalks. The video has also been supplemented by images showing the lifeless bodies of these passerines. These are birds called yellow-headed blackbirds that belong to the avian species of the genus Xanthocephalus xanthocephalus.
Several causes mentioned at the origin of the phenomenon
Pending the results of the autopsy which will soon be performed on several specimens to determine the exact causes of this carnage, several hypotheses have been formulated to try to explain it.
According to the local newspaper El Heraldo de Chihuahua which first reported the story, a veterinarian observing the remains of the birds, suggested that the cause of their death could be due to the inhalation of toxic smoke or vapor coming from a nearby heater. Some have also questioned the significant air pollution in the region. Another hypothesis attributed the cause of this sudden mortality, to the fact that the birds would have spent too much time on a power line and would therefore have been “overloaded”.
Finally, it could more likely be the presence of a predatory bird which would have created panic within the cloud of yellow-headed blackbirds, according to experts interviewed by the site of the British newspaper The Guardian. Indeed, he interviewed several specialists who said that the flight of migratory birds had been “thrown” from above by a raptor swooping down on these prey.
“It looks like a raptor like a peregrine falcon or an eagle chasing a flock like it does with starlings, and it crashed when the birds were forced down,” Richard Broughton, a scientist working for the UK Center for Ecology and Hydrology.
“You can see that they react like a wave at the beginning, as if they were being chased from above,” he added.
This explanation has been validated by Alexander Lees, lecturer in conservation biology at the University of Manchester.
“For my part, by viewing only the video and without the toxicological analyzes of the dead birds, I would say that the most probable cause is that the flock of birds sought to avoid a raptor, by diving to the ground” indicated Alexander Lees to the Guardian.
“The first reaction to finding a plausible explanation is to point to environmental pollution, but collisions with infrastructure are very common. In a flock of birds in close formation, individuals follow the movements of the one in front rather than relying on the surrounding environment. It is therefore not surprising that such events occur from time to time,” he concluded.