Saturday 1 May 2010

Worms, quick, quick!

Blackbird fledglings are out and about. Their urging 'quick, quick' calls to their parent to bring food make them easy to track. If the female is not ready to lay a second clutch, the pair of Blackbirds will divide the care of the brood amongst for up to ten days after the young leave the nest. If the female has already started laying, then the male takes care of the whole brood, running back and fro in search of food for his demanding young. This behaviour is a trade-off: the male taking charge allows shorter intervals between broods - and therefore higher chances that more chicks are produced in a season - but the more young he is feeding, the lower the chances they will all reach independence.
Yesterday, a male sang while it flew toward his charge, like he didn't want to waste a minute - a stressed, multitasking parent. Then, landing nearby, caught a large earthworm and banged it against the ground several times while the fledgling called insistently. The male offered the worm to the young, and he swallowed it voraciously.

Gradually the young will learn to catch prey or find food by themselves, and by 2-3 weeks after leaving the nest they will reach full independence.

More information:
PHILLIP J. EDWARDS (1985) Brood division and transition to independence in Blackbirds Turdus merula. Ibis, 127: 42-59. here.

4 comments:

  1. Hi Blackbird. Just stumbled upon your blog by chance and have really enjoyed it. Its nice to find someone digging a little deeper into things than simply posting photos. I look forward to following your posts and exchanging notes from time to time.
    Regards
    Allan

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  2. Thank you Allan for your words. I am also enjoying researching the posts. Welcome!

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  3. interesting observation. a couple of years ago, our blackbirds which are always fairly tame, esp the male ones, had a juvanile chick that had a very badly damaged leg. it apparantly was broken, dangling limply. the male continued to feed mealworms to this one juvanile long after he ignored or even chased off its siblings, which somewhat bullied the injured chick. the chick hung about for quite a long time, gaining increasing use of the leg, still being fed. eventually the leg healed up so as to be virtually unnoticable. this i think goes to show the intelligence of birds. they can vary their behaviour and are not just mere robots. the male obviously recognised the chick required extra care, which paid off in the end. and it also shows their resiliance to injury

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  4. Hi Andy, lovely observation and nice to read the story of your garden blackbirds and the recovery of the injured young. It can go both ways though, with young that can't keep up being abandoned and all efforts directed to healthier ones with more chances of survival.

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