Saw this story from the States on the Press Association wires last night - quite interesting, and a handy aide memoire not to forget it's Valentine's Day tomorrow...
Thinking about it, hormones in overdrive have always been the reason why long distance Spring twitches are dodgier than Autumn ones...
The Wood Thrush shot above is courtesy Elizabeth Gow/PA Wire; the perched Purple Martin by Tim Morton/PA Wire; The flying Purp by Patrick M. Koamer/PA Wire and the pic of the geolocator by Bridget Stutchbury/PA Wire.
SONGBIRDS HOT-TAIL IT ON A WING AND A PRAYER
By John von Radowitz, Press Association Science Correspondent
Songbirds have a spring in their wings when it is time for them to fly to their breeding colonies, a study has shown.
Scientists who strapped tiny tracking devices to the birds' backs were amazed by the speed at which they made the journey from South America to the US.
Data from the geolocators showed that some birds covered over 311 miles per day, travelling more than three times faster than experts had previously estimated.
Scientists tracked the migration flights of five Wood Thrushes and two Purple Martins.
In autumn the birds flew to their winter homes in South America, returning the following spring to breed back in the US.
The spring return flights were two to six times more rapid than the autumn migrations, the researchers found. One Purple Martin took 43 days to reach Brazil but dashed back to its breeding colony in only 13 days.
Professor Bridget Stutchbury, from York University in Toronto, Canada, said: "We were flabbergasted by the birds' spring return times. To have a bird leave Brazil on April 12 and be home by the end of the month was just astounding. We always assumed they left sometime in March."
The research is reported today in the journal Science.
The coin-sized light-sensitive geolocators recorded sunrise and sunset, allowing the scientists to calculate the birds' position on the Earth at different times.
They were mounted on the birds' backs by looping thin straps around their legs.
Prof Stuchbury's team attached the devices to a total of 14 Wood Thrushes and 20 Purple Martins at the start of the study in autumn, 2007. In the summer of 2008 they managed to retrieve the geolocators from seven of the birds and reconstruct their migration routes and wintering locations.
The scientists found that prolonged stopovers were common during the autumn migration.
The Purple Martins, members of the swallow family, rested for three to four weeks on the Yucatan peninsular in Mexico before continuing on to Brazil.
Four Wood Thrushes spent one to two weeks in the south-eastern US in late October before crossing the gulf of Mexico.
The study showed that Wood Thrushes from a single breeding population did not scatter over their tropical wintering grounds, but spent the winter in a narrow band in eastern Honduras or Nicaragua.
"This region is clearly important for the overall conservation of Wood Thrushes, a species that has declined by 30% since 1966," said Prof Stutchbury. "Songbird populations have been declining around the world for 30 or 40 years, so there is a lot of concern about them.
"Tracking birds to their wintering areas is also essential for predicting the impact of tropical habitat loss and climate change. Until now, our hands have been tied in many ways, because we didn't know where the birds were going. They would just disappear and then come back in the spring. It's wonderful to now have a window into their journey."
If any Wheatears or Sand Martins are online at present down Africa way, they may care to consider the article, and get a bloody shift on.
Eyes to the skies everyone, eyes to the skies...
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Graham Clarkson wrote...
Interesting science. Looking forward to some migrants too! Shall we run a book on who sees the first Wheatear at Marshside this spring? Could be fun.
Posted by: Graham Clarkson | February 13, 2009 1:25 PM