It weighs 9 grams and crosses the Sahara twice a year.
From Willow Warbler
The populations that breed in the far east of Siberia travel more than twelve thousand kilometres to southern Africa twice a year, the longest migration of any bird weighing less than ten grams.
From Willow Warbler
It moults twice a year, which is exceptional among the leaf warblers: it renews its entire plumage on the breeding grounds and again on the wintering grounds, an enormous energy cost for such a small bird.
From Willow Warbler
Its English name, chiffchaff, reproduces its song literally: a repeated, irregular "chiff-chaff" that is the surest way to identify it.
From Common Chiffchaff
It takes in up to a third of its own weight in insects every day.
From Common Chiffchaff
Ringing has revealed that males and females choose different habitats in winter.
From Common Chiffchaff
It was split from the common chiffchaff as a species on its song and its genetics.
From Iberian Chiffchaff
It was recognised as a species in its own right in the 1990s thanks to its song: where the common chiffchaff repeats a monotonous chiff-chaff, the Iberian bird adds a faster, higher second part, and that difference is enough for females to tell the males of each species apart.
From Iberian Chiffchaff

Ecosystems