Why did the birds fall from the sky? Here is what the experts think

Hundreds of yellow-headed blackbirds have been filmed appearing to fall from the sky in mysterious circumstances in the Mexican city of Cuauhtémoc.

Footage from a security camera shows a flock of migratory birds appearing as black smoke. Most of them manage to fly, but later footage showed some dead birds scattered on the city streets.

The cause remains unclear, but experts said it is very likely that the herd flew from top to bottom due to the threat of a bird of prey.

According to the local newspaper El Heraldo de Chihuahua, which first reported the story, a veterinarian suggested that the cause of the incident could be related to high levels of pollution, driven by the use of wood-burning heaters, agrochemicals and cold weather in area. Another suggestion was that the birds were electrocuted while resting on power lines. There was speculation on social media that it may have been caused by 5G technology.

By Dr. Richard Broughton, an ecologist at the UK Center for Ecology and Hydrology, told the Guardian that although he could not see a predator in the video, he was 99% sure it was caused by a bird of prey he could have made the other birds to be pushed towards the ground. The birds above have pushed them down to collide with buildings or on the ground.

"You can see they act like a wave at first, as if they were being pushed from above," Broughton said. Dr. Alexander Lees, a senior biology lecturer at the Metropolitan University of Manchester, agreed.

"People always seem to associate these phenomena with environmental pollutants, but such collisions are very common. "In a large herd, birds follow the bird's movements forward instead of actually interpreting their wider environment, so it is not surprising that such events occur from time to time," he added.