Birds That Fly in a V Formation Use An Amazing Trick

Why do some birds fly in a V?

Most people would say that they do it to save energy, which would be right. But it turns out that birds in a V are actually pulling of a feat that’s more complicated and more impressive than anyone had imagined.

Here is the standard explanation for the V-formation:
As a bird flaps, a rotating vortex of air rolls off each of its wingtips. These vortices mean that the air immediately behind the bird gets constantly pushed downwards (downwash), and the air behind it and off to the sides gets pushed upwards (upwash). (See this image if that’s not clear.) If another bird flies in either of these upwash zones, it gets free lift. It can save energy by mooching off the air flow created by its flock-mate.

This all makes sense, but it represents decades of largely theoretical work. Scientists calculated how air should flow around a flying bird based on what we know about planes, but almost no one had taken any  actual measurements. Henri Weimerskirch changed that in 2001, when he fitted pelicans with heart-rate monitors. He found that birds at the back of the V had slower heart rates than those in the front, and flapped less often.

It was an interesting study, which confirmed that birds benefit from flying in a V. But it didn’t address why or how they do so. That’s what Steven Portugal wanted to know.

Lees meer:  Not exactly rocket science

Radio tag reveals epic phalarope journey

A tiny geolocator has uncovered a hitherto unsuspected extra-long migration by a Scottish Red-necked Phalarope.

An RSPB tracking device weighing less than a paperclip has helped scientists uncover one of the world’s great bird migrations. It revealed that one particular Scottish Red-necked Phalarope migrated thousands of miles west across the Atlantic to the Pacific Ocean, a longer journey than that recorded for any other European breeding bird.

Lees meer: Birdwatch

Why Timing of Bird Migration Is Changing

Researchers at the University of East Anglia have found out why birds are migrating earlier and earlier each year.
 
Experts have long suspected climate change is somehow driving this advancing migration pattern. But new research published today reveals that individual birds migrate like clockwork -- arriving at the same time each year.

However, climate warming is resulting in earlier nesting and hatching earlier each year, and this appears to be linked to the advancing migration.

Lees meer: ScienceDaily

Magpie Parents Know a Baby Cuckoo When They See One

Cuckoos that lay their eggs in the nest of a magpie so that their chicks can be raised by the latter better hope that their young are not raised together with other magpies. The chances of cuckoo fledglings raised in mixed broods being fed by their foster parents are much lower, according to research led by Manuel Soler of the Universidad de Granada in Spain. The findings are published in Springer's journal Behavioral Ecology and Sociobiology.

Lees meer: ScienceDaily