Howdy,

Here's an interesting article from the London Times.

Dan Victor, Seattle, WA <dvictor at u.washington.edu>

---------- Forwarded message ----------
Date: Tue, 21 Jun 1994 07:22:07 -0700 (PDT)
From: Harold Fuller <halfu at u.washington.edu>

Time of plenty for tits;Feather Report;Outdoors
Derwent May
18 June 1994


Young blue tits have been popping out of holes everywhere holes
in trees, lamp-posts, old kettles and petrol-cans, flower-pots,
and nest-boxes in people's gardens. Sometimes as many as ten come
flitting out one after the other into the wide world. They take
refuge straightaway in the depths of the dark-green June foliage,
where they are easy to hear, but not easy to see. They keep up a
perpetual hissing murmur, while their parents feed them
indefatigably on caterpillars that they have picked up from the
leaves of the oak and hazel trees.

The adults usually feed the young on large caterpillars, which
they bring one at a time. Some caterpillars could inflict a nasty
bite on the young birds' cheeks, so the parents kill them by
knocking their heads sharply on a branch and it would be hard to
do that with more than one caterpillar in the beak. But if they
are going to carry only one caterpillar, then it might as well be
a large one. The parents themselves eat any small ones they
encounter.

It has been estimated that in a normal June there may be up to
100,000 moth caterpillars gathered on a single oak tree. The
breeding season of the tits has evolved to ensure that the young
birds are being fed at this time of plenty.

If you do see the young birds, they are unmistakable. They look
duller than the bright-blue adults, but have conspicuous yellow
cheeks, whereas their parents' cheeks are white. They have gone
through various hazards before getting out of the nest.

Blue tits have two surprising predators at this time weasels and
great spotted woodpeckers. Weasels are good tree-climbers, and
often get into a blue tit's nest-hole and devastate the brood.
Researchers into tit ecology in Wytham Wood, near Oxford, where
there are large numbers of nest-boxes on the tree trunks, have
sometimes climbed their aluminium ladders and opened the lid of a
box only to have a weasel leap out at them.

Great spotted woodpeckers are too large to get into the holes
but they bore a hole of their own in the trunk, or in the wall of
a nest-box, and get at the young that way.

The new broods will be left to their own devices about a
fortnight after they leave the nest. Then they will have to come
out of the leaves, and show themselves more. They will be
mingling with young great tits, which also look rather drained of
colour compared with the adults apart, again, from their
characteristic yellow cheeks.

Young coal tits, too, feed in the oaks and birches, although
they are commoner in conifer woods. They are the most distinctive
fledglings of all these three species, as they have not only
yellow cheeks, but also a marked yellow tinge to their wings.

The different species all feed together, but they remain rivals.
Great tits will snatch food from blue tits, and both blue and
great tits rob the even smaller coal tit. The coal tit's size
gives it a further disadvantage: it loses heat more easily, and
needs to spend longer each day looking for food. It is a deft
little bird, though, as people who have seen it at their bird
tables will know: rather than confront the larger birds, it will
fly in swiftly to pick up morsels they have dropped.

Food may be plentiful now, but mortality hits the tits as the
year goes on. Usually, by the time spring comes, there are no
more blue or great or coal tits around than there were the spring
before. That means that from all these noisy families in the
trees, perhaps only one adult and one fledgling will survive.

Cats, magpies and sparrow-hawks are all on the prowl. But for
the moment, at any rate, in the long, warm summer days, the
living is easy for the tits.

What's about: Birders Watch out for noisy young great crested
grebe on lakes and reservoirs. Twitchers Rose-coloured starling
at Beachy Head, East Sussex; pectoral sandpiper at Cresswell
Pond, Northumberland; hybrid roseate x common tern at
Netherfield, Notts. Details from Birdline, 0891 70022. Calls cost
36p a minute cheap rate, 45p per minute at all other times.

This article is copyright 1994 The London Times.