Wildlife update 3: Petrels and prions / by Jerry

When penguin work wasn't pressing I've been concentrating on many of the Island's other birds, mainly the smaller flying ones.

Giant Petrels

The Northern Giant Petrel chicks had started to hatch just before I departed and were looking pretty big upon my return. They were all sat alone on their nests, spending their time snapping and threatening to vomit on anyone who walked past (most of the birds use this effective defence mechanism) and waiting for their parents to return with food. As they lose their downy grey feathers their adult ones start to show through, at this young age they're all sleek and shiny grey-black. It's about this time they start exploring – walking away from their nest to fight with bits of tussock.

At about a month old the chicks start getting left on their own.
I'd been doing weekly checks of the study area, checking on their progress, as several volunteers had been doing while I was away. Then in early March I spent a few days going round weighing, measuring and ringing all the chicks. As with the other species, weighing gives a simple impression of general health, how successful a season it's been and how it compares to previous years as well as being a useful marker when it comes to looking at survival rates and long-term changes. There were a few monsters among the chicks, ones over 7kg with beaks over 10cm long.

At about two months old they're still downy but much bigger and with adult feathers on the way.

Now they're starting to fledge. I'm still doing weekly checks but more often I'll come across an empty nest and then have to search around to see if the chick has genuinely flown off or just gone on an extended exploration.
Three months old; patches of down revealing dark juvenile feathers. At this stage they are regularly visited by parents returning with food.
The Southern Giant Petrels breed and nest about a month later than the Northerns so there's still some big fluffy ones about, though I'll be weighing and ringing them soon.

About four months old and they're ready to fledge. This was the very first egg to be laid in my study area this season, back in mid-September.


White-chin Petrels, Blue Petrels and Antarctic Prions

There's not too much long-term monitoring of these species, but there are a small number of burrows that needed to be checked for chicks. Although it can be a cold, wet and muddy job it is one I enjoy as I feel really privileged to be seeing these young birds looking so fat and fluffy. However of all the wildlife I work with it is probably the White-chins that inflict the most injuries. Not because they're particularly aggressive (although there's always the odd one that wants to kill you) but because they've got incredibly sharp claws. They'd usually use them for climbing tussock and digging burrows but if you can remember Sam Neill talking about velociraptors at the start of Jurassic Park, that's what they can do.

Young White-chinned Petrel starting to develop adult feathers around the face.
The adults are rarely seen on land as they usually come in at night to avoid predatory skuas and head straight to their burrows, this is particularly true of the Blue Petrels and Antarctic Prions that are about the size of a large thrush while the White-chins are like small gulls. They're often seen at sea, where they congregate behind the ship, and at night, particularly stormy, overcast nights where their calls echo through the dark.

Big, fluffy Antarctic Prion chick - really just a ball of fluff with a beak.


Skuas


I missed seeing the skua chicks when they were tiny and cute, but instead had the responsibility of measuring, weighing and ringing them once they were old enough to fight back. Thankfully our adult birds aren't as aggressive as other skuas, I'm thinking about the Bonxies in Shetland here, so the adults usually complain but standing loudly beside you and shrieking. Most of the juveniles are flying now and are congregating on the beaches to fight over scraps before they'll head to the mainland or out to sea for the winter.

Adult Brown Skua issuing a warning.