1. Counting penguins.
There are two species of penguin that breed on Bird Island, the gentoo penguin and the macaroni penguin. In order to guage the health of the penguin populations, and ultimately the health of Antarctic ecosystems in general, it is important to know how many penguins are breeding in a given year, and this means counting them at various stages of the breeding cycle. Counts are done at several penguin colonies during build-up (when the penguins arrive and claim a nest site), after all eggs have been laid and finally just before the chicks fledge. Build-up had already passed by the time I arrived on Bird Island, so my first penguin counting experience was a nest count of macaroni penguins at Big Mac colony. Big Mac, as the name suggests, is very big, housing around 40,000 pairs of penguins in any given year. Counting all of them would be impossible, so instead we estimate the total number by counting all the penguins in two ten-metre wide transects that run from the top to the bottom of the colony. The transects are marked out with yellow stones and divided into 5x5m squares, with each square being counted in turn to give the total.
On my first penguin counting day, the 30th November, the weather was grim – windy, raining and cold – so by the time Stacey and I reached Big Mac we were already rather soggy and dejected. Big Mac is steep and made up of rocks and loose rocky shale, and the rain had made it slicker than an ice rink. It was also completely covered in angry penguins. We edged our way gingerly down to the bottom, trying not to slip, with the penguins honking their disapproval at us on all sides. At this stage the macs had just laid their eggs and both birds from each pair were hanging around at the nest, creating an extremely high penguin density. Since every vaguely flat crevice was occupied by a penguin sitting on an egg, there were few stable footholds, so I slithered and stumbled my way up to the first set of yellow rocks with furious penguins pecking at my ankles the whole way. At the top of the first quadrat we turned around and counted the nests in it. ‘Twenty-eight,’ Stacey yelled at me over the cacophony of penguins. ‘Thirty-six,’ I bellowed back. We counted again. The cold began to penetrate my clothes.The rain had not abated and even the penguins looked wet and miserable, hunched over their eggs. On the third count we both got the same number, and were able to move on to the next quadrat. More slipping and sliding and, at times, crawling along on my hands and knees through the hordes of angry penguins. And so it went on until, 24 quadrats later, we reached the top; cold, wet, bedraggled and caked in penguin guano. We immediately moved on to the second transect, and by the time we had finished it I had lost all feeling in my hands and had developed a deep loathing for penguins, rain, the person who devised these transects and Antarctica in general. Fortunately there was a field hut nearby, and after a fortifying cup of tea I felt much more cheerful and decided that I didn’t hate penguins after all, which is lucky really, given what my job is.
There are 80,000 penguins at Big Mac colony. Fortunately we don't have to count all of them.
Counting gentoo chicks is a team effort.
2. Weighing penguins.
Another indicator of the health of penguin communities is the average weight of the penguins. In years when there is a lot of food available penguins will be fatter, and fat, healthy penguins are more likely to be able to raise their chicks to fledging. The weight of the chicks just before they fledge is also a good indicator of whether they will survive the winter, and thus provides information on annual survival rates. The traditional way to weigh a penguin is to grab it, shove it into a bag and weigh it using a pesola spring balance. However one of my jobs here on Bird Island is to look after the penguin weighbridge, an ingenious device created by the boffins at BAS, which allows automated penguin weighing.
The penguin weighbridge is situated beside Little Mac, a small macaroni penguin colony that contains around 400 nests. The location of Little Mac means that all the penguins, when walking to and from the sea, pass through a narrow bottleneck of land, and this is where the weighbridge has been placed. It is simple enough in theory – the penguin steps onto a weighing platform, its weight is recorded and then it steps off again. In practice it is much harder to obtain accurate weights in this way since measuring the weight of a moving, hopping penguin is a very difficult thing to do. Imagine trying to record the weight a person who was jumping up and down on the weighing scales and you begin to understand the difficulty. If we could somehow persuade the penguins to get onto the weighing platform one at a time and stand still for a few seconds before getting off then the whole thing would be much easier, but alas, the penguins are not this co-operative. Nevertheless, after several years of development and using insanely complicated algorithms, the BAS weighbridge now works extremely well and can accurately weigh a moving penguin to within a few tens of grams. The exact design of the bridge is top secret because, astonishingly, there is more than one group of scientists working on automatic penguin weighing and we don’t want our competitors to steal our ideas.
Catching a wily macaroni penguin.
Weighing a penguin the old-fashioned way.
Stacey demonstrates the 'handbag' method for carrying a penguin.
Some macs contemplate crossing the weighbridge.
One at a time, please!
3. Sticking stuff onto penguins.
This summer there is a tracking study being carried out on the gentoo penguins, which involves attaching GPS logging devices to individual birds to find out where they go whilst at sea, and also Temperature-Depth-Recorders to find out where and how deeply they dive. Deploying the devices on incubating birds is fairly straightforward. It is just a case of ambling along to the colony, choosing a penguin that is about to switch places with its partner on the nest, waiting for the changeover to happen and then grabbing the partner and attaching the devices before it heads out to sea. Attaching the devices is a two person job. One penguin wrangler catches the penguin with a net and places a hood over its head, making it look like a tiny little kidnap victim. The penguin is then restrained by straddling it with its head facing out the back, holding its feet with both hands and pressing the flippers against its body using your knees. This gives the second penguin wrangler access to the penguin’s back, where the devices are attached using a combination of tape, glue and cable-ties. The penguin then has a number painted onto its chest using black hair dye (which will disappear when the penguin moults later in the season), making it easier to identify, and is released. Job done and home in time for tea. However, when the devices need to be retrieved a few days later there is no choice but to go to the colony and wait for the particular tagged penguins to return. Penguins don’t keep to strict timetables, and device retrieval, we soon discovered, can involve waiting for up to six hours in the icy cold, silently willing the next penguin that comes out of the sea to be the one with a number on its chest. The study is thankfully now complete, and there are fourteen numbered penguins running around the island somewhere. I believe some of them have got together and will be playing a team of chinstraps next month in the South Georgia all-Penguin Amateur Football Championships.
Restraining the penguin.
Attaching a GPS datalogger.
Logger and TDR, securely attached.
Penguin wranglers love their work.
The final indignity - an ID number on the chest.
Penguin number 1, now playing centre-forward.
4. Some pictures unrelated to the text but still featuring penguins.
A partially moulted gentoo chick.
Large gentoo chicks relentlessly pursue the adults, begging for food.
Obi-wan has taught you well, but you are not a penguin wrangler yet.
Actually it is a device for reading the electronic implants which some of the penguins have.
A macaroni penguin with its chick.
The dangers of falling over when you are still fluffy.
Relaxing on a sunny day.
This penguin wrangling business is a piece of cake.