Under ideal conditions, common swifts can cover more than 500 miles a day for more than a week, report scientists. It seems an unimaginable feat for such a tiny bird, but raptors have adopted a clever strategy that enables these epic migrations.
Like a migratory bird, common fast (Apus apus) are aptly named. These highly mobile creatures spend more than 80% of their lives in the air when they do not breed, and much of this time is spent migrating from northern Scandinavia to their winter destinations in West and Central Africa.
For these long-distance migrations, scientists previously estimated an average speeds of 310 miles per day (500 km / day), but new explored published in iScience updated this figure to 354 miles (570 km / day). More impressively – not that this isn’t impressive enough – the new study shows that rapids can travel fafaster and faster than previously thought. Fastest, swifts can cover more than 500 miles (830 km) per day for ninedaily stretching. The new journal was written by Susanne Akesson and Giuseppe Bianco of the Center for Animal Movement at Lund University in Sweden.
The researchers used miniature geolocators to track 45 adult common swifts during migrations in 2010, 2012 and 2014 (the devices weighed less than 3% of the birds ’body mass, so as not to slow them down). Of these, 24 were recaptured later; swifts almost always return to their specific breeding grounds, making it possible to recover their trackers after a single migration season. Akesson and Bianco managed to recover 20 rapids who recorded their movements for a full year, including fall and spring migrations.
As the data showed, “common swifts breeding in the northernmost part of European territory” covered an average of about 9,900 km (6,150 miles) during the autumn migration and about 7,900 km (4,900 miles) in the spring, “surpassing those recorded for populations in the south. and central Sweden, ”according to the study.
The rapids use a combined strategy to achieve these record trips, “including high burning speed at a stop, fly-and-forage during migration, and selective use of tail winds,” the scientists write. By eating snacks along the way, the speedsters can reduce the “high energy cost of flight,” according to the study.
As noted, the birds also take advantage of winds. Somehow, they know when the winds will be the most favorable. Scientists are not entirely sure how they can do this, but they suspect it is a reaction to changing air pressure caused by passing weather systems. Regardless, the winds give the rapids a 20% boost during the spring compared to the fall. The winds are the biggest help during the transition from the Sahara and the Mediterranean Sea. Interestingly, the winds may explain why the previous speed ratings for the speed bumps were too low.
Swifts may be the fastest migrants, but other birds are equally impressive long-distance travelers.. Last year, scientists reported during a record flight by a rod-tailed star (Lapland slime). This bird flew continuously for 11 days, covering 7,987 miles (12,854 km) of Alaska to New Zealand. Scientists suspect that rod-tailed gods have a special metabolism that enables this, along with ability without sleeping for a long time.
More: A record bird recently flew continuously from Alaska to New Zealand.