This has been a busy month with
the penguins. Al and I, with plenty of assistance from the others on base, have
been out counting and weighing chicks across the whole island.
First up came the gentoos. There
are 7 separate colonies containing between 200 and 1500 nests (counted at the
end of October). The beauty of counting nests is that they don’t move around,
whereas young penguins do. Especially once they’re large enough for their
parents to leave them and head off to sea to feed. While awaiting their return
the young ones crèche together in large, noisy and smelly (though undeniably
cute) groups. The largest of these groups can contain several hundred chicks
and require some co-ordination of counters.
We’ll try and position ourselves
so we’ve a good view of a group, but also so we’re preventing them from running
off or mingling with other groups. Then everyone counts as accurately as they
are able. Chicks do move around but you do your best and hope that those missed
are made up for by any double-counted. When done everyone calls out their
figure, like a chaotic bingo hall, and if close enough we’ll move on to the
next group. In most cases we aim to have at least six counts, with no more than
Assembled to count a
group of gentoo chicks.
As we know how many occupied
nests there were from the October counts we can say how many chicks have
survived per nest. Gentoos lay two eggs though of course not all survive. A
productivity of 1.2 to 1.5 would indicate a good year.
Stopping for lunch at
the edge of the colony, it soon becomes the centre of the colony as the chicks
head over to investigate.
Similar counts are carried out
with the macaroni penguins, although with only one chick per year their
productivity is naturally lower. This may be a product of their different
behaviour, specifically foraging further from the colony for food. When
entering the smaller colony, Little Mac, penguins cross a gateway that can
identify and weigh them. An individual can typically leave the colony in the
morning 500g lighter than it arrived the previous night – all food passed on to
the chick, not bad for a 4kg bird!
We also weigh the penguin chicks
at a specific age each year. Weight is a good indicator of general health and
many birds are weighed prior to fledging. For the penguins this requires a team
of volunteers willing to get muddy and smelly as the chicks have to be caught
in a net, put in a strong bag and weighed on a spring balance. It takes less
than a minute before they’re running back into the mass of fluffy compatriots.
Still a bit fluffy,
young gentoo chicks taking their first steps into the sea.
The penguin chicks are now
starting to leave. The macaronis clear the colony within a week, disappearing
off to sea while their parents will return in a week or two to moult their
feathers before spending another winter in the ocean. The gentoo chicks spend
more time familiarising themselves with the water; wading in and putting their
faces below the surface then getting freaked out and running back onto the
beach when they get knocked over by a wave. Gradually they get more
accomplished and start swimming, though often are too fat to dive underwater
properly, needing to lose some weight as they develop their swimming muscles.
Not only are there
waves, the young penguins also have to deal with over-playful fur seal pups,
themselves just getting used to the water and inquisitive about anything near
As they lose their downy
feathers and a little fat they become more streamlined and start to look like
proper penguins. They spend more time in the water and start heading further
from the shore.