Weather Radar Detects Thousands of Bats Flying Out of Arizona Tunnels

by Jon D. B.
(Photo credit: Auscape/Universal Images Group via Getty Images)

Watch as the National Weather Service’s radar goes haywire as thousands of bats fly out of Arizona cave systems.

A once-hidden phenomenon takes place in what appears to be a freak storm cycling out near Phoenix, AZ. A strange outburst on radar caught the eye of NWS meteorologists Sunday night, perplexing experts. Finally, after reports flooded in on social media – the team had their culprit: bats.

One NWS meteorologist, Sean Benedict, was interviewed by AZFamily. He clarifies what led them to pinpoint the bats and their radar phenomenon as one:

‘That doesn’t look like a normal shower, the way everything is sort of fanning out. They don’t really have a uniform direction. That’s usually your clue initially that it’s probably animals flying around.’

Sean Benedict, NWS

What has these bats registering on radar?

NWS in Phoenix are having a little fun with their followers. Asking on Twitter, the weather service wants guesses as to what is causing such a stir.

Finally revealing their answer, the NWS clarifies further on the nature of bats in Phoenix. This particular swarm is “probably thousands of Mexican fee-tail bats that migrate here for the summer.”

For Arizona, the beginning of fall typically hosts the largest amount of bat sightings. The small flying mammals come out in the open as they begin making their way to Mexico for warmer temperatures. Since bats are warm blooded like us (and most other mammals), they migrate to keep warm through the winter.

However, Mexican free-tailed bats flood Phoenix during the summer, too. Their colonies reach peak size around July, and number in the tens of thousands. Whenever either of these migrations happen, these bats swarm out in the evenings to feed – causing vast swaths of dense movement to register on radar.

Ready to see these bats in motion?