Grist to the Mill

02 April, 2004


"In April, a male bird barely has time to yawn and stretch before he must start to fill the airwaves with his song. It's an important and urgent chore, and no sleepy male bird can afford to be silent or drowned out. A bird's spring fortunes can rest on these vocal efforts at daybreak.

The dawn chorus is rarely heard and appreciated in its fullness. In theory, it's easy to rise in the pre-dawn darkness and hear a procession of birds singing for an hour or so - blackbirds and robins first, then woodpigeons, great tits and wrens. But few people bother. They hear the sounds from their beds but seldom get up to listen. It's a pity, because the dawn chorus can be overwhelming, even in the gaden. It's more like a competition: weighty with consequence and full of intrigue.

The reasons for song - the continual reminder to peers of territorial ownership and advertisement to females - are well-understood. But the timing of the peak of song is not so well understood. Sound travels better at dawn than later in the day, making this a good time to make a public statement (certainly better than competing with suburban traffic and lawnmowers). Also, dawn is a poor time to feed; the half-light makes searching difficult, and insect prey is inactive in the cold. So, if there's nothing better to do, why not sing and remind your neighbours that you're there? [following on here, if this is the case then why not at midnight, or 2am?]

Another thoery for the dawn peak is to do with tension between the sexes. Female birds don't sing, but many lay eggs at dawn. When they have finished, they are at their most fertile, equiring sperm as soon as possible to fertilise a further egg. Intoxicated by this need, they are particularly vulnerable to advances by any male - not just their mate's. So, to protect his paternity, the male rises early and floods his mate's consciousness with song from the moment she wakes up, telling her he is available, hearty, and ready for copulation as soon as she leaves the nest."

(Dominic Couzens)

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