Birds evacuate nesting area ahead of tornado

BBC : In May 2013 Henry Streby of the University of California, Berkeley, and colleagues tagged 20 golden-winged warblers in order to monitor their seasonal 5000-km migration between Colombia and the US. The birds had just completed their journey to the Appalachian Mountains in April 2014 when their geolocators showed them taking flight once more on 26 April—one day before a series of tornadoes struck the central and southern parts of the US. Over the next five-day period, they flew a total of some 1500 km to the Gulf of Mexico and back. The researchers propose that the unexpected journey was made to avoid the severe weather, which the birds were able to anticipate because of their ability to hear the deep rumble tornadoes emit in the infrasound range. Sound in that range can travel thousands of kilometers, but it is below what humans can hear. In their paper published in Current Biology, the researchers conclude that as global warming causes ever more severe weather events, such behavioral responses of animals could be well worth studying.