‘We think that these behaviors represent a previously unknown cognitive ability …’
FRISCO — Some migrating birds may be able to sense weather patterns on a hemispheric scale, helping them optimally time their nonstop transoceanic flights.
Bar-tailed godwits, the ultra-marathon champions of migration, breed in Alaska and spend winters in New Zealand and a recent U.S. Geological Survey-led study suggests that these birds can sense broad weather patterns.
Careful monitoring of the birds suggest they time their departure to match the best possible atmospheric wind conditions possible within a two-week window. Remarkably, not only were the conditions optimal for take-off, but they almost always provided the best possible conditions for the birds’ entire flights, as far as 7,000 miles in eight days between Alaska and New Zealand.
“We think that these behaviors represent a previously unknown cognitive ability that allows bar-tailed godwits to assess changes in weather conditions across widely separated atmospheric regions in different parts of the Pacific Ocean and to time their migration patterns accordingly,” said Robert Gill, Jr., an Emeritus Scientist with the USGS and lead author of the study.
The findings are part of a new scientific publication by collaborators from the USGS, the National Oceanic and Atmospheric Administration, and the University of Groningen and the NIOZ Royal Netherlands Institute for Sea Research.
The researchers used detailed information on individuals tracked by satellite transmitters, along with data on wind conditions across the Pacific Ocean, to investigate migration patterns along the 18,000 mile annual route of the bar-tailed godwit. Their study determined that bar-tailed godwits are able to make efficient decisions about when and where to fly during nonstop flights of up to 10 days long between wintering areas in New Zealand and breeding areas in Alaska.
“There are a number of broad-scale prevailing wind patterns through the Pacific Ocean, and the godwits take advantage of these winds to facilitate successful migration between their wintering and breeding areas,” Gill said.
“These wind patterns appear to be teleconnected, or linked, across broad expanses of the Pacific Ocean,” said Gill. “Just like airline pilots, birds occasionally have to abort flights or change course drastically when they encounter severe, unexpected weather,” noted David Douglas, Research Wildlife Biologist, who like Gill, works out of the USGS Alaska Science Center and is co-author of the study.
The researchers observed two birds that made abrupt course changes when they encountered rapidly developing cyclones along their flight paths. In one case, the prolonged flight change resulted in the bird not breeding that season, likely due to energy spent fighting the headwinds of the storm.
The report on this study, entitled “Hemispheric-scale wind selection facilitates bar-tailed godwit circum-migration of the Pacific,” was recently published in the journal Animal Behaviour.