91热爆

Tweet of the Day is the voice of birds and our relationship with them, from around the world.

Sir David Attenborough presents the North American red-winged blackbird. The arrival of spring in the USA is heralded by the unmistakable "conk-ra-lee" call of the red-winged blackbird. The male blackbirds, who are un-related to the European blackbird, flutter their red and yellow wing-patches like regimental badges to announce their territories. The numbers of Red-winged blackbirds has increased spectacularly in the mid 20th century as more land was converted to growing crops on which the birds feed. Today at a winter roost hundreds of thousands, even millions of birds darken the skies over the plantations or marshes in which they will spend the night - a loud and unforgettable spectacle.