Monday, December 8, 2008

Coal Tit Parus ater

I am an amateur naturalist trying to teach myself something about everything alive in my garden.

Taken on the same morning as my Blue Tit photo, photo 1 shows a Coal Tit (Parus ater) on my garden birdfeeder.

Averaging around 9-gm, Coal tits are the smallest British tit and easily recognised by their black crown and the white patch at the back of their head: No other British tit has the same. They are common in the UK, often inhabiting conifer woodland, the RSPB website giving the number of breeding pairs as 653,000.

What other I know about coal tits I've learned from reading The Titmice of the British Isles (John A.G.Barnes, publ. David&Charles 1975), this includes the rather charming fact that once mated a male-female pair will tend to remain bonded across the years, assuming both manage to survive that is; Annual mortality for coal tits is around 80%.

I was surprised to learn that coal tits make their nests very near to ground level in tree stumps or even in holes in the ground. I've spent many hours walking through woodland and don't recall ever having seen one, which I suppose must mean they're well concealed. Females lay on average 9 eggs around April-May. Coal tits are diligent parents and have been recorded making upwards of 60 visits to the nest in a single day to feed their chicks.

Coal tits spend a great deal of their day - around 90% - feeding. Given their small body size and slender beaks they consume the smallest insects (typically 0-2mm according to the book above) among the tits, an example of evolution driving different species to specialise in different feeding habitats and foodstuffs to best survive in one another's company. An exception to the rule is beech mast, which is so plentiful in Autumn that many different tit species come together to enjoy the glut.

Something I didn't know is that coal tits will sometimes store food (seeds etc.) for later consumption. Typical hiding places might be holes or under moss on tree trucks. There is a record of one bird digging up a seed that it had hidden more than a fortnight previously.

Finally, I have often wondered about the time at which birds go to bed. Of course 'late in the day', but is that as light is dimming, or say, a little after sunset? Dr. Barnes' book has answered my question: the coal tit is on average an early rooster, typically abed 1.7 minutes before local sunset. Good night!

4 comments:

Anne Perry said...

I just stumbled across your wonderful blog while looking up alternate names for the Viola tricolor (heartsease or Johnny Jumpup). I hope you find the time to update in the new year!

Henry Walloon said...

Thanks for the encouragement Anne.

Never fear! My rate of publication goes up and down but I've no plans to abandon my blog.

Henry Walloon said...
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