December 18, 2014
By Jonathan Webb
...After disappearing to Colombia for the winter, (click here) 10 of the tagged warblers returned in April 2014. The team was in the field observing them when they received advance warning of the tornadoes.
"We evacuated ourselves to the waffle house in Caryville, Tennessee, for the one day that the storm was really bad," Dr Streby said.
Elsewhere in the US the storm had more drastic consequences. At least 84 tornadoes caused 35 fatalities and more than $1bn (£0.6bn) in property damage.
After the storm had blown over, the team recaptured five of the warblers and removed the geolocators.
These are tiny devices weighing about half a gram, which measure light levels. Based on the timing and length of the days they record, these gadgets allow scientists to calculate and track the approximate location of migratory birds.
In this case, all five indicated that the birds had taken unprecedented evasive action, beginning one to two days ahead of the storm's arrival.
"The warblers in our study flew at least 1,500km (932 miles) in total," Dr Streby said.
They escaped just south of the tornadoes' path - and then went straight home again. By 2 May, all five were back in their nesting area....
