December 6, 1996

Adelie penguins

Peter's alarm clock beeped at 8:00am; I had been asleep for a few hours. He shuffled through the hut and joined the awakening in the kitchen. Through the vague din of voices and gear being rearranged in the hall, I fell back to sleep until about 11:00am. It had been an exciting night of looking and listening out in the Adelie colony--but I was still exhausted. Several hours later, I surfaced and made my way into the kitchen where Sue and Fiona were entering data and having tea. Breakfast--a Vegemite sandwich and a piece of cheese hit the spot!

A glance out the window, and I could see the ice had changed course and was heading into McMurdo Sound with a fair wind. I was glad to have had the chance to record the night before--it would be my only chance, as the weather changed. Partly cloudy and windy was the forecast. Peter and Kerry had joined Ainley's group as they made a fenced enclosure and set up a weigh bridge to measure Adelie traffic to and from a colony on the near edge of the rookery. It was a peaceful lull in the day and I had the fortunate chance to spend some time talking with Sue and Fiona about their project, "Sperm Competition in Adelie Penguins." Studying reproductive behaviour in any creature poses many challenges and I asked Fiona about the background for her current research.

She explained, "All animals are trying to pass on as many genes into the next generation as possible. In monogamous species, where one male is paired to one female, the male is limited to fathering however many offspring the female can produce. However, some males can increase the number of offspring they produce by copulating with extra-pair females--females other than their pair partner. By doing this they potentially increase the number of genes they pass on. If a female mates with more than one male, the sperm from both males will compete within her reproductive tract to fertilize the egg."

As regards the penguins at Cape Bird, Fiona continued, "Male Adelie penguins will engage in extra-pair copulations (EPCs) and will also sometimes switch partners during the prelaying period, so sperm competition will occur in the females. We are combining behavioural observations with paternity analysis, by DNA fingerprinting, to investigate who fathers offspring and under what conditions. We have four people recording copulation behaviour around the clock during the pre-laying period--from the time the birds arrive at the colony, in mid-October, until the time that they lay in Mid-November. We are watching 50 pairs and recording times of copulation and who is involved and whether the copulation results in sperm transfer. Then, when the chicks hatch, in mid-December, we take a small blood sample from chicks and from parents. We take these back to a laboratory at Leicester University to analyse them."

In the 3 years of field work, Fiona and members of her group have been able to observe the following, "In all, 15% of females switch mates during the pre-laying period and 10% of females engage in EPCs. DNA fingerprinting has shown that 3% of offspring result from EPCs. Pair males protect their paternity by copulating frequently. Male Adelies engage in an average of 57 copulation attempts in a breeding season. This ranges from 13 to 107 attempts for any one male. In fact, males copulate so often that they run out of sperm. On average only 42 attempts result in successful sperm transfer, in the rest the male fails to produce an ejaculate."

She concluded by saying, "The unique thing about penguins is that the outcome of copulations can be identified by observation; this is not possible in other species. This has allowed detailed questions of sperm competition to be answered, furthering our understanding of sexual selection."

I was looking forward to following her out to the study site to have a look at what she faced in a field situation--the disposition of the colony and the birds themselves, whom she had gotten to know very well by now. While Fiona got her gear ready, I picked up the threads of several conversations with Sue. We had a fair amount in common...As high school teachers, she is in her 14th year and I recently retired after 13 years in the classroom, we compared notes about kids and learning. We agreed on the need for teachers to have substantial research and field experience beyond the confines of the school environment--as a way of reinvigorating their commitment to education and the demands of teaching. Lack of support for field work in Antarctica was one reason she left one school for another and the mitigating reason for me leaving teaching altogether. Sue was pleased with the reception she has had for her research by the administration at the Otago Girls' High School in Dunedin. Her students will no doubt benefit from her work down here--it is important for young girls to see women excelling in the sciences and in field work--areas of academia which have been long dominated by men.

As lunchtime rolled around, several members of the weigh bridge project showed up at the hut: mission accomplished. The corral was built, the scale installed and the electronics running smoothly. Fiona and I trekked down through the skua gauntlet to check in on the work before heading to her study site. The Adelies were unperturbed by the construction and, for the most part, slept on their nests, occasionally stirring to adjust an eggs and position a few nest stones. A few individuals inspected the perimeter of the fence; it was a quiet time.

Scale installed

(L-R) Peter Wilson, Kerry Barton, Mike Biegel, Grant Ballard and David Ainley in front of their handywork

Adjacent to the weigh bridge, Ainley and his team had erected a booth which contained the data receivers. Nearly 100 penguins were selected for monitoring. Each bird had a tiny electronic element implanted in the scruff of its neck, "half a transformer," as Mike Biegel, the designer described it, which triggers a reciprocal "half" in the bridge. As a penguin moves over the scale, the data logger records the identity of the individual, its weight, and whether it was coming or going from the colony. By tracking this information, the group hopes to gain insight into feeding success, the transfer of biomass within the colony, and the dynamic of colonial movement. The system is an extraordinary design!

We left them to their work and let the Adelies get used to the alteration of the colony--which was not entirely new to them, as they had already experienced the bridge last year. It provides no impediment and seems to be rather non-intrusive--a key aspect of any field endeavour.

Fiona had selected her site based on a number of variables, most particularly a manageable colony size (in this case about 50 pairs) and viewing access so she could see from 360 degrees around the group. We approached slowly; the site had a landmark--a wooden crate with a chair. Fiona explained, "When the penguins are hunkered down in an 80 knot gale, we take shelter here. You can feel stones being hurled against the back of the box. But immediately after the wind dies down, there is a lot of activity and we need to be right there." I shuddered...

Surveying the site

Fiona in her wind shelter

While Fiona took count of who was in and who was out of the colony, as part of the daily census, I took a few photographs of a neighbouring group. She had a map identifying nests and a tally sheet where she noted individuals and egg sightings. As I wandered off, Fiona motioned to me. A truly remarkable individual was making its way along a snow drift.

Map of the penguin colony

"That bird is 1 in 100,000--a leucistic penguin," she explained to me, "They don't have the ability to produce black plummage."

"So, it is not an albino?" I asked, never having heard the term before.

"No, because, if you look carefully, you can see that the bird has pigmented feathers."

Sure enough, the wings and back were a buff, beige colour and the beak an almost cherry red. I enquired about its being rejected and Fiona described the bird's appearance in the colony a few years ago. At first, the penguin--a female--was surrounded and examined by numerous other birds. In time, she found a mate and has successfully bred. This year, she lost her egg and her nest was looking pretty scant of rocks.

Leucistic penguin

We finished our work and tried recording some sounds--it was tricky as the wind had not abated. It was fun for Fiona to listen to the more close-up sounds that these creatures make. The hour was getting late and we made for the hut.

Our party had grown by two, Peter Coville, a Kiwi and Sompon Wanwimolruk, from Thailand but based in New Zealand had joined the crew. They are pharmocologists from Otago University here to make toxicology studies and assess liver function in Adelie penguins. We warmed ourselves with a round of whiskey and beer and Peter Wilson and I made dinner--a feast of stir fried vegetables, marinated lamb and beef and a pot of rice. Sompon had brought some delicious Thai spices and some wine as well.

Following dinner, Mike Biegel and I tried rigging a microphone to work with his video camera, in the hope of shooting some Adelie footage later in the evening, if the wind died down. Neither came to fruition--we couldn't get a rig to work and the weather stayed about the same. Meanwhile, in the lab three candles burned...Nate Polish's wife, Ellen had put together a menorah for Hanukkah: a green metal crayon box with penguins on the cover and a series of nuts and washers glued to the surface to hold candles. Nate lit the candles, while outside a pod of killer whales swam by and the ice moved into the sound...

Nate Polish