When Mom and Dad Have Different Migratory Routes, Kids Fly Right Down the Middle

It sounds like the setup to a bad joke told by zoologists: What do you get when you cross a bird that always flies to the west with one that always flies east? But the punch line is weirder than you’d guess. Birds’ migratory routes are partly coded into their DNA. A baby that inherits genes for two different routes doesn’t commit to either path. Instead it bounces between them and may take a wild zigzag straight through the middle—even if that route is perilous.

 Laboratory tests in the past have hinted that this might be true. One study of captive warblers, for example, crossed a type that orients itself to the southwest when it’s ready to migrate with a type that orients southeast. The offspring pointed themselves directly south.

Lees meer: Discover Magazine

Insights into birds' migration routes

By tracking hybrids between songbird species, investigators have found that migration routes are under genetic control and could be preventing interbreeding. The research, which is published in Ecology Letters, was conducted using geolocators that, like GPS, record the position of a bird and allow its long distance movement to be tracked.

Compared with their parents, hybrids exhibited increased variability in their migratory routes: some used intermediate routes across less suitable areas, while others used the same routes as one parental group on fall migration and the other on spring migration.

Lees meer: ScienceDaily

Revealed: The mystery behind starling flocks

The mystery behind the movements of flocking starlings could be explained by the areas of light and dark created as they fly, new research suggests.

The research, conducted by the University of Warwick and published in the journal PNAS, found that flocking starlings aim to maintain an optimum density at which they can gather data on their surroundings.
This occurs when they can see light through the flock at many angles, a state known as marginal opacity. The subsequent pattern of light and dark, formed as the birds attempt to achieve the necessary density, is what provides vital information to individual birds within the flock.

Lees meer: ScienceDaily

Birdsongs automatically decoded by computer scientists

Scientists from Queen Mary University of London have found a successful way of identifying bird sounds from large audio collections, which could be useful for expert and amateur bird-watchers alike.

The analysis used recordings of individual birds and of dawn choruses to identify characteristics of bird sounds. It took advantage of large datasets of sound recordings provided by the British Library Sound Archive, and online sources such as the Dutch archive called Xeno Canto.

Lees meer: BiologyNews

The Bird That Paints Its Eggs With Bacteria

It’s spring. A female hoopoe—a bird that looks like a pickaxe painted in a tiger’s colours—lays her eggs in a hole within a tree. The eggs come out milky blue, but they soon change colour to a mucky brown. That’s not just because the nests are dirty, as Wikipedia currently claims. It’s also because of a liquid that the female produces.

Lees meer: Not exactly rocket science