Secret Migrations – La fauvette à tête noire

Nightingales, starlings, robins, chickadees… all these familiar birds of the European gardens belong to the great family of passerines.

In autumn, many of them leave our latitudes for the south, in search of a more indulgent climate.among these “songbirds”, the black-capped warbler is particularly observed by scientists. Widespread throughout Europe, the warbler likes forests but does not disdain parks and gardens of large cities. The ringing of millions of warblers for nearly a century, and the installation of tiny electronic sensors on these travelers weighing less than 20 grams, have enabled us to learn more about the warbler’s migration. And the latest results do not leave biologists astonished. The warbler is an “athlete” of migration.

To prepare for its journey, it moults and changes its feathers, switching from a daytime to a night-time lifestyle. At night, it will be able to travel long distances while minimizing its risks of encounters with predators. It knows how to orient itself thanks to the stars, recognizes the variations of the magnetic field. It practices hyperphagia before each stage of its migration. It feeds on berries, fruits, and anything else it finds along the way until it takes on thirty percent of its weight, which will allow it to complete several hundred kilometers in one go, before replenishing its reserves.The traditional migration routes of the black-capped warbler in Europe are well known. The traditional migration routes of the black-capped warbler in Europe are well known.

A first route takes the warblers southwest to Spain, the Strait of Gibraltar and West Africa. A second route takes them to the South-East towards the Balkans, the Bosphorus strait and the Middle East.some “dissident” warblers however forsake the ancestral southern route for a much more unexpected destination. They migrate to the north! In this episode, we meet a very common passerine bird, but in reality quite exceptional, a small bird of twenty grams that seems to play with all the obstacles, and even to take advantage for once of the alterations that Man makes to its environment.