An experiment on bird migration patterns has inadvertently revealed that some bird species possess a unique ability to detect inclement weather hours or even days before it hits. Researchers from the Universities of Tennessee and Minnesota found that the golden-winged warbler, which travels to the Appalachian mountains from Columbia during the northern hemisphere summer, can detect bad weather up to 24 hours in advance, giving it plenty of time to evacuate.
Publishing their findings in the journal Current Biology, researchers from the two schools say they accidentally discovered all this after pulling data from special geo-locators which they attached to 20 of the birds back in May 2013. The initial goal was to track the general migration patterns of these tiny songbirds, which on average weigh only about nine grams each.
But just days after 10 of the tagged warblers returned to the U.S. from Colombia, a massive storm system just so happened to be making its way into the Midwest and South. Prior to meteorologists even detecting this storm, which caused at least 84 tornadoes, 35 deaths, and more than $1 billion in property damage, some of the birds that still had trackers on them left the area.
Data later collected from the geo-locators revealed that the birds had traveled some 400 miles south to the Gulf of Mexico, at least 24 hours before climate scientists even became aware of the storm’s presence. Somehow, these tiny birds were able to detect the storm long before anyone else did, an amazing ability that scientists attribute to their low-frequency hearing capacity.
“The most likely tip-off was the deep rumble that tornadoes produce, well below what humans can hear,” explains BBC News, citing what the researchers had to say post-discovery. “Noise in this ‘infrasound’ range travels thousands of kilometres, and may serve as something of an early warning system for animals that can pick it up.”
Many Other Bird Species Likely Capable of Detecting Weather Before Humans Can
What makes the warblers’ escape even more incredible is the fact that it occurred while weather conditions at their nesting site were still completely normal, at least according to human perception. There was no indication, based on tracking and observation data, that anything was amiss at the time the birds left for the Gulf.
Speaking to BBC News, Dr. Henry Streby, one of the researchers from the University of California, Berkeley, explained that many other birds species more than likely also possess this special hearing ability. From his own birdwatching assessment at the time, Dr. Streby recalls bird populations plummeting days before the storm even hit the radar.
“It’s very unlikely that this species is the only group doing this,” he is quoted as saying. “It seemed like there were far fewer birds – so I suspect it’s not a species-specific trait.”
Dr. Chris Hewson, a senior research ecologist at the British Trust for Ornithology, agrees with the infrasound hypothesis. Based on his understanding of weather formation patterns, warblers, falcons and other birds must have a special sense for how these weather events form, long before human understanding and technology is able to pick up on it.
“[Y]ou can see from the weather data that there doesn’t appear to be any alternative cue that they could be picking up on,” he told BBC News, referring to the low-frequency sounds that trigger sudden bird evacuations.
“We know that birds can alter their route to avoid things during regular migration,” added Dr. Streby. “But it hadn’t been shown until our study that they would leave once the migration is over, and they’d established their breeding territory, to escape severe weather.”
*Image of “birds ready to migrate” via Shutterstock