John Metcalfe was CityLab’s Bay Area bureau chief, covering climate change and the science of cities.
The warm weather has activated the state's legendary hordes.
How's the weather in Texas? One might say hairy, fluttering, and filled with a cacophony of high-pitched shrieking.
A warm spell has hit Texas, and it's triggered restlessness not just among joggers and cyclists. Over in the western part of the state, huge swarms of bats are taking off and chasing bugs in the night sky. These groupings are so large they appear almost like rain storms on Doppler, as recently demonstrated above the cave-dotted savanna of the Edwards Plateau.
An Air Force-base radar spotted one colony emerging around 5:45 p.m. on Sunday, 33 miles northwest of Del Rio. It's the blue-green jellyfish shown here attacking the U.S./Mexican border:
About 15 minutes later, another colony awoke and soared off into the sunset. It appeared on radar as an overturned, aquamarine crescent moon south of Carta Valley:
As anyone who's been dive-bombed by bats at Austin's airport knows, great numbers of the furry fliers have picked Texas for their seasonal hunting grounds. Austin's under-the-bridge bats are legendary, and the biggest bat colony on earth swoops into Bracken Cave near San Antonio every spring. (With roughly 20 million bats, it's said to be one of the largest accumulations of mammals in the world.)
The animals help the locals manage mosquitoes and other pests—the Bracken multitude can eat 140 tons of insects in one night—and in return the locals extend their own occasional favor. Last year, for instance, conservationists scuttled plans for a 3,500-home subdivision outside San Antonio, fearing its street lights might disrupt the squeaking hordes. As one of the people involved said: "We would have had hundreds of bats congregating on the porches, around street lights, around swimming pools."