Spring may be a long way off, but it’s in the air already. Great tits, always popular around the bird-table, are beginning to sing now as they mark out their breeding territories.

The classic great tit song is a crisp metallic "tea-cher, tea-cher" sound which cuts through the hum of traffic and whose rhythmic pattern earned the bird the old name of "saw-sharpener". But although this loud song is easy to recognise, the great tit (Parus major) has an astonishing repertoire, which includes over 70 different calls and songs and individual birds having around eight songs that they use regularly. In fact, it’s said that if you hear a loud and unfamiliar song in the garden, then it’s probably a great tit.

Audio clip with a great tit singing (credit: LazyPixel / Brunner Sébastien / Getty Images)

But why should a great tit have so many songs when other species seem content with one? Ornithologists explain this by the “Beau Geste” hypothesis. The hero of the novels about the French Foreign Legion by P.C. Wren, when under siege from his attackers, propped up the bodies of dead soldiers around the walls of his fortress to convince his enemies that the fort was well-defended.

That seems to be what male great tits do. By singing different songs from different places in their territories, they give the impression to rivals that their chosen patch is better defended than it really is and persuade their competitors to keep away. 

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