Hundreds of Birds Fall to Their Death, Experts Weigh In

There has been growing concern after hundreds of yellow-headed blackbirds plunged to their death in the northern Mexican city of Chihuahua. 

The phenomenon was captured on camera and the footage, which shows a massive flock of migratory birds diving towards the ground, by Monday had gone viral on social media. Many of the birds were able to fly away but hundreds died after hitting the ground. 

It was initially reported that, according to a veterinarian, the incident was caused by high levels of pollution driven by the use of wood-burning heaters, agrochemicals and cold weather in the area, according to Euronews Green. 

Since then, other theories have emerged. One suggestion was that the birds were electrocuted by a nearby power line, while another conspiracy is that the installation of 5G technology was to blame. 

Experts now are claiming that a predatory bird may have caused the blackbirds to drop toward the ground. The yellow-headed blackbirds had migrated to Mexico from Canada, where they are prone to being preyed upon by the predatory northern harrier. The birds travel in large flocks during their annual migration and they may have dramatically shifted direction to evade their predator. 

"For my part, and from one video and no toxicology, I’d still say the most probable cause is the flock murmurating to avoid a predatory raptor and hitting the ground," Dr Alexander Lees, a senior lecturer in conservation biology at Manchester Metropolitan University, told The Guardian.

"There always seems to be a kneejerk response to blame environmental pollutants, but collisions with infrastructure are very common. In a tightly packed flock, the birds are following the movements of the bird in front rather than actually interpreting their wider surroundings, so it isn’t unexpected that such events happen occasionally."

Dr. Richard Broughton, an ecologist with the U.K. Centre for Ecology & Hydrology, echoed his sentiments. 

"This looks like a raptor like a peregrine or hawk has been chasing a flock, like they do with murmurating starlings, and they have crashed as the flock was forced low," he said. "You can see that they act like a wave at the beginning, as if they are being flushed from above."

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