Guillemots go to sea
Malcolm Ogilvie
For cliff-nesting seabirds,
the time comes when the chicks must leave the ledges and take to
the sea. Their first flight is immediately followed by their first
swim! The departure of Guillemot chicks is the more dramatic because
it occurs well before they can fly, usually at about 20 days old
with true fledging a further 40 days away. It
is a remarkable sight as the half-grown chicks, accompanied by a
parent, flutter frantically on stubby wings gliding steeply down,
to a belly-flop landing on the water below.
(left
- Guillemots in breeding plumage. The bird on the left is the 'bridled'
form with white eye ring and stripe, which is commoner in northern
populations.)
Virtually all Guillemots
in Britain nest either on sea-girt cliffs or on small islands whence
the chicks can readily reach the water. In the high arctic, however,
the closely-related Brünnich's Guillemot often nests on inland
cliffs, hundreds of metres from the water, with a steep scree slope
beneath and then a broad strip of tundra sloping to the shore.
The departure of Brünnich's
Guillemot chicks from a colony is one of nature's more memorable
spectacles. I've stood beneath a 600 metre inland cliff, the birds
massed on the ledges above and, as a bonus, the intervening scree
slopes alive with nesting Little Auks. Each chick, as it launched
itself off the ledge and started its fluttering glide, was followed
not by one, but by several adults, often five, occasionally ten.
They called loudly and incessantly, as if in encouragement, lowering
their feet and spreading their tails, and flapping their wings jerkily
in order to slow themselves down to the speed of the chick. The
latter also called, more shrilly, adding to the general cacophony.
Once on the sea, the chick would swim up to a single adult, presumably
one of its parents, while the remaining birds moved away, the excitement
over, though perhaps to fly back up to the ledges for another go.
(left
- Brünnich's Guillemot has a thicker bill with whitish gape
- shown here in winter plumage)
There was a wide strip
of tundra between cliff and sea and, inevitably, some chicks fell
short to land, heavily, on the ground. When this happened, one or
more adults often landed beside it and set off to complete the journey
on foot. This, though, was when the danger from Glaucous Gulls,
which were attempting to grab the chicks in mid-air, was replaced
by an equal danger from arctic foxes, which had gathered beneath
the colony. They rushed to and fro, grabbed a stranded chick, a
quick bite to kill it before scrabbling a small hole and burying
it then darting away to catch another. Here was their winter food
supply when the good feeding of the summer is long past.
As more and more chicks
reached the sea, a raft of adults and young formed just offshore.
Shortly, they would all set off swimming to the main feeding areas.
Both Guillemots and Brünnich's Guillemots often feed up 50
kilometres or more from the colony. It makes good sense to cut down
on all those journeys and to take the chicks to the food instead.
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| Dr
Ogilvie is a natural history writer and editor, formerly a research
scientist with the Wildfowl and Wetlands Trust, and resident
on the island of Islay since 1986. Until 1997, a member of the
'British Birds' editorial board and also one of the editorial
team which produced 'Birds of the Western Palearctic'. |
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