Alderney Gannetries
16th July 2007
With
the Jetstream, and its associated plethora of low pressure systems,
firmly in
place across Britain for the majority of the months of May and June,
the 2007
Seabird Season had proved to be the most difficult any of the current
seabird
enthusiasts could remember. Not only were there problems with strong
winds,
rough seas and plenty of rain on many days, but it was also difficult
to secure
boats during the relatively few calm windows of opportunity!
With
the vast majority of the Channel Island European Shags taking a year
out of
breeding in 2007 (probably due to the very stormy weather in the early
spring,
which may have prevented the adults from finding enough food to reach
breeding
condition), and with breeding gulls and tern numbers looking low also,
we were
unsure how the Northern Gannets may have fared in 2007.
In
view of the exceptional weather conditions and the unusual seabird
breeding
season, permission was obtained from the Channel Islands Ringing Scheme
to
extend the window to visit the gannetries until 16th July.
This is
some 16 days beyond the usual cut-off date of 30th
June…which was
put in place around 20 years ago. With the continued poor weather for
most of
the first half of July, it was looking like even this extension would
not
enable a visit to be made. However, at the eleventh hour a small
ringing team
of Catherine Kinnersly, Chris Mourant and Paul Veron managed to make
the trip
(on the very last day possible!).
The
slight sea and light winds on the northbound sea journey from Guernsey
raised
hopes that we would be able to make a landing. Two European Storm
Petrels were
seen to the north of Guernsey. Richard Keen and other fishermen have
been
reporting larger than usual numbers of Storm Petrels around Guernsey
and Sark
this summer. It will be interesting to see what the autumn pelagics
produce in
terms of Storm Petrel numbers when they start in mid-August.
Having
set off from St Peter Port Harbour at 1030, we reached the base of Les
Etacs at
around noon. There was a small swell at the base of the rock. Looking
with
binoculars we could see that the landing slope and edges of the colony
contained mostly relatively small young with white down. However,
further up
the rock and into the main plateau (at the heart of the colony) we
could see
large young already in their very dark chocolate, white flecked
plumage. Some
were as big as adults.
From
this, it became clear to us that the gannets had nested more or less on
time in
2007. It was not a repeat of the late season evidenced in 2006. It was
also
abundantly clear that the gannets have been very successful in raising
young in
2007.
Catherine,
Chris and Paul landed at the usual place and slowly worked the landing
slope
and first gulley. We took our time and managed to ring 187 chicks.
Almost all
were covered in white down. None of the brown-feathered chicks was
touched…and
interestingly not one of them was seen to move even 30 cm from its
nest. Some
of the larger downy chicks were sprouting their brown wing and tail
feathers –
and some of these were mobile, but only in walking within a few metres
of their
nests.
We
took an hour and a half to work very slowly up the landing slope and
across the
first gulley…leaving the upper and lower edges alone. When we
reached the edge
of the main plateau we stopped to take a good look. Here we could see
lots of
advanced young including many with their brown flight feathers well
formed. We
unanimously agreed not to enter the main part of the colony for fear of
causing
too much disturbance to these birds. We returned back the way we had
come –
again causing minimal disturbance. Most birds were already back on
their nests.
One
adult and several chicks were successfully cut free from nylon
netting/rope.
Although 5 or 6 dead adults were seen no rings were recovered on the
rock this
year.
Richard
Keen picked us up, and rowed us to the adjacent stack. Here we climbed
up the
“chimney” to reach the main part of the colony. Another
hour was spent slowly
working our way through the birds. This area is not part of the main
colony,
and as expected the chicks were less advanced than in the main section.
It was
relatively easy to ring this rock, again causing very little
disturbance. 103
chicks were ringed before we were picked up again.
With
the tide having turned, Richard explained that landing on Ortac would
not be
possible. We decided however to go up to the rock to take a close look.
This
proved to be very worthwhile. As expected the nesting gannets on Ortac
appeared
to be a little behind Les Etacs with only a couple of fully-feathered
brown
youngsters seen from the boat. Most of the chicks observed were still
covered
in white down, although many were sprouting their brown wing and tail
feathers.
Broad
conclusions were similar to Les Etacs with the gannets breeding season
being on
time and very successful in 2007, despite the poor weather. The success
of this
species probably lies in the fact that it feeds on different fish
species (i.e.
not sand eel) and it can and does forage at considerable distances from
the
breeding colonies (unlike shags, gulls, terns and auks).
Although
only 290 chicks and one adult were ringed on the trip, valuable data
was
obtained.
As
an aside…for the second (third?) year running, we are convinced
that gannets
are attempting to nest on one of the westernmost outlying rocks of
Renonquet.
The top of the rock is very white and 30+ adult birds were seen
circling over
the rock. It is very difficult to get close to the rock, as it is
circled by a
dangerous reef. However, even if nesting is being attempted, it is most
unlikely to be successful as this rock is very low making any nests
very
susceptible to storm surge and spray.
On
the return boat journey we saw a first year gannet flying west very
strongly
and purposefully behind an adult. Whether this bird was one of the
first young
to leave the Alderney gannetries or had its origins further north is a
matter
of mere speculation. What was clear is that it looked mighty fine on
the wing!
20th
July 2007
PS
– On 29 July Paul passed close to Ortac and Renonquet returning
from the UK on
Condor Ferries. Although he did not have binoculars he saw 50+ gannets
standing
on the two rocks to the west of Renonquet, and many looked like they
were
attempting nesting – even though the rocks are restricted in
height above the
sea. It really does look like gannets are now spilling over from Ortac
(which
appears full) to try to establish a new colony off Alderney.
Let’s hope they
find a more suitable rock very soon!