Of what I speak is a seabird colony existing where the marine ecosystem has not been subject to wide-scale pollution from agricultural and civic runoff, fish depletion, introductions of alien species, harmful plankton blooms (“red tides”) and lots of other things that currently ravage most marine ecosystems of the “civilized” world. I speak of the Ross Sea, the last ocean on Earth where seabirds are capable of being too successful in their breeding. Hmmmm, yes, you heard me right. That is a statement that should give you pause for contemplation, and refers to a concept foreign to most marine ecologists. And what could I possibly mean by this? How can a colony of seabirds ever be too successful?

If you’ve been following my previous dispatches to Ice Stories for this recent Antarctic summer, one was called “Royds Tranquility” and another was “Beaufort Chaos”. In those I reported on the contrast between the Royds penguin colony (one “city” in this story, 2000 penguin pairs) and the more populous colony at Beaufort Island, the other city (60,000 pairs). The Royds colony was very quiet but at the time miserably failing owing to the 70 km walks that most parents were making to find the ocean and food…and 70 km back. The extent of fast ice was very unusual owing to very calm winds last winter and spring. Other than birds attempting to remain resolute on their nests, no others were present. Deserted eggs were everywhere, as more and more adult penguins giving up and going off to feed, their mates choosing not to return.

At Beaufort Island, where the ocean was at the penguins’ doorstep, just a short skip away, penguins were coming and going in multitudes, and because many nested in suboptimal habitat– being forced to do so because the good spaces had all been taken– some were losing their eggs too. But there were huge numbers of eggs still under other parents, being warmly incubated. In addition, due to a short journey from wintering areas just before nesting, all colonies, Royds included, began the season with their respective breeding populations at maximum, i.e. above normal. “Everybody”, it seems, attempted to nest! [If you’ve not read the earlier dispatches, perhaps do so before proceeding further in this one.]

About 40 km to the east of Beaufort, the colony at Cape Crozier was in a similar state to Beaufort: maximum proportion of a large colony, twice the size of even Beaufort (150,000 pairs), attempting to breed. Well, we could not follow up at Beaufort (couldn’t get there at the end of the season) but did have the opportunity in regard to Crozier. I think the stories for both Beaufort and Crozier were pretty much the same, although, being smaller, likely Beaufort didn’t have quite the problem experienced at Crozier.

At all our penguin colonies, there are the “super breeders” who almost always produce young– despite conditions– and then there are the “other” penguins. Mainly the super breeders have learned, through experience, about the vagaries of factors that penguins need to know about. This involves just 25% of the population, or thereabouts; the remainder of penguins almost always fail unless conditions are really easy. This season, the super breeders came front and center at Royds. Not only did they successfully hatch their eggs (unlike the klutzes) but also raised the maximum of two chicks. Therefore, even though 75% of nests failed, the total average chick production of the colony was 0.6 chicks per nest, which isn’t all that bad, given that in good years, an average 0.9 chicks are produced among all nests in which eggs are laid.

What these super breeders had figured out was that they could feed through narrow cracks in the ice and not walk all the way to the open ocean. Then, the ice opened into a polynya [patch of open water in the ice] off Royds, as I described in the “Minke Friends” dispatch. From then on, foraging was easy and the Royds chicks ballooned to become heavier than even last season, averaging around 3800 grams by the time they were 6-7 weeks old and within a week or so of fledging. That’s BIG for an Adélie penguin chick! As is the usual, the Royds chicks didn’t form crèches [groups of penguin chicks] because almost all the time, at least one parent was present to protect them.

Below are two images of Royds, taken on 17 January 2009, showing all the adults present. The reason that there are an equal number or more chicks than adults is because most chicks had a sibling…so two chicks for every successful nest.

Chicks and adults at Royds.

Penguin adults and chicks at Cape Royds, Antarctica.

So now, what about the other penguin city, the one at Crozier (standing in for Beaufort in this tale)? At Crozier, not only did a maximum number of birds attempt to breed, but almost all successfully hatched their eggs. This was because initially finding food was easy, as long as a parent only had its own mouth to feed. Not long after peak hatching, though, the parents began to make longer and longer foraging trips as they depleted food nearby. Of course these seabirds had help from whales and fish in this consumption, unlike the case for any other place in the World Ocean.

Chicks at first did ok, but once they reached the age of maximum growth rate, around 3 weeks of age, troubles began for Crozier. Eventually, parents’ trips reached three days long and less food was returned as some was digested on the trip back (these penguins hold the food in their stomachs, and then regurgitate it to their chicks — see previous dispatch — and once that cold wad begins to heat up in the parents’ stomach, it begins to digest, a common occurrence when the trip back to the colony is more than a day long). Well, basically the chicks at Crozier, though reaching appropriate size (height) for their age, became way under weight. At week 7 they were more than 1 kilogram (1000 g) lighter than Royds birds, and their feather development was halted. In fact, average weight was lower than we’d ever measured it at Crozier. Many chicks began to die of starvation. There were just way too many of them to be fed with the result that almost all were under-fed. In fact, breeding “success” at Crozier was 1.0 chicks crèched per original nest (it’s usually no better than 0.9). Wow! That’s a lot of chicks when you consider there were 150,000 nests to begin with.

Looking to the immediate future, it would seem that the chances for eventual survival of the Crozier chicks is close to zero, quite in contrast to the fat, vigorous but many fewer chicks at Royds. The Royds chicks should have a great chance for survival.

Below are images from Cape Crozier taken on 20 January. The contrast with Royds is dramatic, as almost no adults are present, even though the chicks are just a few days older than those shown in the images above from Royds. Sad.

Cape Crozier chicks with few adults in sight.

Cape Crozier chicks with few adults in sight.

Here you can see lots of chick carcasses. These chicks, unfortunately, have died of starvation. Also sad.

Crozier chicks and carcasses.

So, this is all pretty amazing, but we had to go through the entire season to see how things played out, and flip-flopped Royds vs Crozier. In the last several seasons (2001-2005), we witnessed somewhat similar events at Crozier, but chalked it up to effects of the big icebergs that were present then. The icebergs occupied a large portion of the Crozier colony’s foraging area.

Those icebergs have been gone now for two seasons. So, we have to consider other ideas to explain what is going on now. Perhaps, it seems, Cape Crozier has grown too large!! This rarely could happen to a seabird colony elsewhere in the world. Mostly this is so, because the population is kept low by pollution, toxic die-offs, invasions of feral animals or other type events; or breeding success is low owing to difficulty in finding food early in the season (over-fishing). In some warmer-water colonies of seabirds, where the environment allows the population to be present year round, a portion of large populations may just hang out in waters nearby and not participate in breeding. That doesn’t seem to be an option for migratory seabirds nor for seabirds that live in extreme environments, in both cases like is the case for Adélie penguins.

Well, ok, it was a very “educational” season for us, as are many. To complete our education, though, we have to be present in 4-5 seasons hence to tally the winners and losers among the penguin cities. That’s because young Adélie penguins spend their first years at sea and don’t visit the colonies.

For this season we are done, and here is what our camp at Cape Royds now will look like through the winter darkness. (See dispatch, “So, You Want to Be a Penguin Researcher?” for a view of the camp all set up.) In a couple of months you’ll need a flashlight to see this, our camp in a small box….well, a slightly large one.

Our camp.

The reason we go to Beaufort is that it appears to be the true “penguin pump” in this cluster of colonies in the southern Ross Sea. We want to confirm this. The colony at Cape Crozier produces lots of chicks, like Beaufort, but it has a huge area for expansion, if the penguins are up to that. Mostly they are not, because more and more penguins in one area leads to more competition for food in nearby waters. To avoid that, young Crozier penguins might want to find a territory elsewhere, or not, like at Cape Bird.

The Beaufort colony also regularly produces a lot of chicks, but until recently there was no room for the young prebreeders that result from that to find a spot, except in very poor habitat (see below). That’s why young Crozier birds didn’t want to move there either. The Beaufort breeding area has been hemmed in by vertical cliffs behind, and open ocean the other way. Penguins would be everywhere where they possibly could be, wall-to-wall so to speak. Penguins that didn’t want to tussle for a spot definitely would show up elsewhere like Cape Royds: lots of space there and no competition for food. We know this because we’ve been making the icebreaker trips almost every year since 1996 in order to band a bunch of chicks at Beaufort. In later years, we see these banded birds at Beaufort but in disproportionate numbers we see them at the other colonies, too…until recently.

Beaufort, 2001.

Here’s a shot of Beaufort from the air taken in 2001; west is towards the background. You can see the ‘shelf’ of gravel on which the colony nestles, hemmed in by precipitous cliffs in the back, snow fields to the west, and the ocean. Penguins are everywhere that there is level ground and no ice (there are about 60,000 nests crammed into this area). The west end of the colony is hemmed in by ice fields (see next photo).

Yes, disproportionate numbers of penguins raised at Beaufort have been going elsewhere until a few years ago when global climate change began to kick in around here. Then, with slightly warmer temperatures the snow and ice fields on Beaufort began to rapidly retreat [sound familiar? Hey, I drove up to see Glacier National Park this past summer to see the glaciers before they are gone….maybe by 2015 they say.] This warming caused the ice to retreat at Beaufort also, thus exposing lots of terrain with lots of small pebbles, ideal for nests.

A new breeding area at Beaufort.

Here is a picture of penguins setting up territories at the west periphery of the colony that until recently, 2001 (see aerial Beaufort photo) was covered (probably for the last 20,000 years) by snow and ice. These penguins were not here in 2001. So, you see, that bad-ee, Global Climate Change, can be “good” sometimes!

Well, there are so many penguins trying to find a nest at Beaufort, and so little space and not enough rocks, that, actually, Global Climate Change is not happening fast enough!! As a result, many penguins are nesting in suboptimal habitat and more than likely they will lose their nests and its eggs. This will force them to be more prudent next season. Either they will set up nests at the west end of Beaufort (see photo above)…the most likely….or many will seek out places like Cape Royds, where lots of stones are to be had along with lots of space (and usually open water; see next blog dispatch).

With stones in short supply, some penguins turn to nesting in guano (penguin poop).

These penguins are nesting in scoops in the guano with almost no stones. All of the stones have been used up by other penguins! More than likely their eggs will roll out of the nest and, in fact, on our next visit following this one, we found eggs EVERYWHERE.

With an insufficient number of rocks holding a nest together, penguins’ eggs roll out and are lost.

There are well over 30 whole eggs in this picture that have rolled out of nests. There simply were not enough rocks for the penguins to build the protective “basket” to hold them.

Still lots of nests had eggs but lots had rolled away– so many that the skuas had too many to eat! The other thing that happens when a penguin has a scoop but no stones, is that it fills up with water. That’s bad for eggs and chicks.

Penguins with drowned nests.

Here are penguins who built nests, and laid eggs, in a depression that initially was dry but now is filled with melt water. There was no room for them on high ground. Yes, there are eggs underneath these birds!! This is a demonstration of how staunch penguins are, in spite of adversity. They won’t give up until the conditions become impossible. These are impossible conditions, and yes, these penguins gave up!

Ill-fated nests.

Here are a bunch of penguins that have built their nests on a nice sandy beach (above). How idyllic! It’s the kind of place that people would hang out; all we need are some palm trees. However, when all that ice in the background eventually melts later in the summer, then the sea is going to come pouring in, waves crashing, to wash the penguins’ feet, but also their eggs and chicks, too. These penguins, too, next season will be looking elsewhere for making a nest!

So you see, and I know you’ve been told this before, Nature works in strange ways. It takes some adversity to convince penguins, and people, to alter their behavior…that is, to stay in higher or safer ground!!!! This is going to be the same for people beginning very soon, as global climate change REALLY gets going. I hear that insurance companies no longer are insuring houses on the US Gulf Coast, owing to increasing numbers of hurricanes and rising sea level. See, if the insurance companies can’t afford this, neither can the rest of us. Where are all those Floridians going to be living? In Georgia, I guess. Penguin Insurance Companies, to stay in business, would not insure these penguins’ homes shown above. (Penguins don’t get government bailouts for bad decisions.)

Every season, we band a lot of chicks at each colony, and in later seasons spend a huge amount of time looking for them when they come back as pre-breeders (teenagers) and then adults. The numbered metal bands are placed around their left wing and this will identify each bird, as well as the year the bird was born and its natal (birth) colony. Once a banded bird begins to breed (its mate or itself laid an egg), we mark its nest with a plastic tag and nail driven into the permafrost. Then we keep track discovering what happens to each banded bird during the course of its lifetime, at least here at the colonies.

Wing Band. Numbered metal bands are attached to the birds when they are chicks. It identifies which colony the bird was born in and what year.

The banding process takes place at the end of the breeding season just before the chicks do their final molt and head out to sea for the winter: 400 chicks each at Royds and Beaufort, 1000 each at Bird and Crozier, each year. We’ve been doing this since 1996 full-scale, with a few banded in 1994 and 1995. So, in total, more than 33,600 chicks banded to date. This banded “sample” of the colony population will serve as an indicator for the movements and survival rate for each colony.

Some of the things we have learned so far are: Adélie penguins do not always return to the colony of their birth and will move from one colony to another to breed and raise their chicks. This is why we call this complex of colonies a “metapopulation”…no colony is independent of the others. What causes penguins to relocate is mainly due to, as we said, access to the ocean, but also the difficulty of finding food or nest stones where there are a lot of penguins. Thus as colonies grow, and resources become harder to come by, penguins are encouraged to move to smaller colonies….just like people!

Beaufort Island Adélie Penguin colony. These grounded icebergs have been here for several years. They are about 1 km off shore and dwarf everything in the area.

Here is the Ross Sea and the coast of Victoria Land in a NASA image taken last week (below). The red stars show the members of the colony cluster that we are investigating. The blue stars show the other Ross Sea Adélie Penguin colonies.

Penguin colonies in the Ross Sea. Photo courtesy of NASA.

Only the Terra Nova Bay (2 colonies) and Cape Hallet colonies have been thoroughly search for our banded birds, thanks to colleagues in the Italian Antarctic Program (Silvia Olmastroni and friends) and New Zealand Antarctic Program (BJ Karl and friends), who camped at each for several weeks. They found one of our banded birds at each of these three colonies. So, now we know that birds within our metapopulation exchange readily among themselves, but also we know that a few, but not many, intrepid penguins go much farther afield in search of a breeding spot. Tourists with sharp eyes have also noted single banded birds at Franklin Island and at Coulman Island.

At Cape Royds, where we are camped, there are about 2000 nests, so looking for bands takes one person about an hour to complete. However at one of the other colonies in our group, Beaufort Island, there are 60,000 nests and the other day it took four of us four hours to search, and doing so without pause. In fact, we were walking more rapidly in search for bands than is our norm.

In past years there has been open water between Cape Royds and Beaufort so helicopter transport was not possible and band searching could not occur at Beaufort. However, this year the ice is thick so helo transport is possible. From Cape Royds it is a 30 minute helicopter ride to the Island and on this day we stopped to pick up help from Cape Bird: Katie Dugger (co-PI on the project) and Len Doel (volunteer from NZ). Unlike the birds at Cape Royds, the Beaufort Island birds walk less than one mile to open ocean. Why then do the Cape Royds birds make the 50 mile trip when they could nest at Beaufort? We’ve given some hints to the answer, but this is a question for another day.

To establish a breeding colony, Adélie Penguins need ice-free land with a supply of small rocks to build their nest. Beaufort Island has a large beach area with plenty of rocks, but also always easy access to the ocean. So this colony is larger than Royds.

Beaufort Island Colony. A large, ice-free beach with lots of small rocks. The brown areas are where the penguins are. This colony has about 60,000 nests.

Searching for bands requires binoculars and a good eye as you walk along the nesting areas. When we found a banded bird at Beaufort we recorded its number and whether it is on a nest, alone or paired and if the nest has eggs we record the location using a GPS.

Searching for bands. It takes patience and good binoculars to find the banded birds in these large groups.

Color anomalies are rare in penguins, but with a colony this size there is bound to be one, today we found a blond penguin. Its color does not seem to affect its ability to survive.

Blonde Adélie Penguin. A rare color anomaly.

A good days work; about 80 banded or known age birds were identified representing all four colonies of birth, Cape Crozier, Cape Royds, Cape Bird and of course Beaufort Island. The vast majority of banded birds were banded as chicks at Beaufort. We found 5 that were hatched and banded at Cape Royds. In another 7-10 days we will visit Beaufort Island again, because by then all the females will have replaced their mates on the nests. Thus, we’ll probably find another 80 banded birds who were not there a few days ago.

End of day. Searching for bands is hard work in the cold and wind. We are ready to head home.

Here’s the view from the front window of the RacTent, looking west toward Victoria Land (Antarctic continent). McMurdo Sound is the stretch from here, the shore of Ross Island, to the mountains in the distance. The silver-gray area is open water; the white in the nearer area is the outer portion of the McMurdo Sound fast ice, the edge being about 1 km away. So, the penguins must be happy having the sea this close so early in the breeding season. They are not expecting open water now. In fact, their breeding strategy is set up to cope with treks over ice by the females, after they lay the eggs. The males have put on enough fat to sit waiting for about two weeks for the females to return. I’ve already seen several nest reliefs, as well as birds coming back and the mate not wanting to get off the eggs. Their hormones are elevated, which makes them want to sit as long as they are not hungry.

I’ve encountered about 80 banded, known birds thus far. All had hatched and were originally banded at Royds except one, a male who originated from Cape Crozier. Of those 80, about 50 are the owners of a nest with eggs, laid by them or their partner. That’s a record for Royds, breaking last year’s record of 30 nests of banded birds. The reason such a high proportion of banded birds so far have eggs, and more are likely coming in the next couple of days, is that the population has aged. All the banded birds are 7 years old or older. The oldest of the banded ones, is 13 years. There are no younger ones because in the past 5 years, when McMurdo Sound was covered along its length by fast ice (more later on that), they were discouraged from coming (walking) this far. Many went only as far as Cape Bird out at the northern edge of McMurdo Sound, where they found a nest site near open water. In any case, the peak of laying has now happened here at Royds. Mostly there are just single birds on nests, happily incubating their eggs. Their partners have gone off to sea to eat. The colony is very quiet.

We’ve now got our stuff set up, including the weighbridge. This is an apparatus that identifies penguins (from the computer chip we inject under their skin) when they walk through a hoop antenna, and at the same time records their body weight. They have to walk through this apparatus because a fence, surrounding the nests of about 80 pairs, has just one opening and in this opening is the weighbridge. Most of these penguins remember this setup from previous years, and those that are new to it watch the others. Quickly, they follow along. The data from this apparatus are stored in a small computer that is contained in a tent. This year I had a bit of a problem with the solar regulator for this system, but folks from the CommShop in McMurdo helped me to replace it. I owe them BIG TIME! In the photo above you see that a fence encircles two groups totaling about 80 nests. A computer is in the tent, powered by the solar panels to the right. The weighbridge is to the left of the tent.

At far left is a photo of a PIT (passively interrogated transponder) and the needle used to inject it under the skin of penguins (and dogs and cats).

At near left is a penguin standing on the scale while it investigates the antenna hoop that it just walked through. The item to the left is a photocell that, working with another on the other side of the antenna, turns the system on or off depending on which one gets tripped first by the penguin. The weighbridge allows us to gather information that would have been unheard of just 15 years ago.

One can reliably capture a penguin only once; the second time the penguin has its suspicions and is wary. Thus, once we inject the PIT tag we can then determine its weight as it changes over the season, and also the weight of the food that it fed to its chick(s), by subtracting its departure weight from its arrival weight on each visit to the nest. We’ve found that this amount of food varies depending on several things, including the size of the colony in which the penguin lives. At Royds, a tiny colony, parents bring back more food more often than at Cape Crozier, a large colony, where there is a great deal of competition for food. Little did we know when we started out!

We have set out in the 12th year of a project in which we seek to understand why Adélie Penguin populations have been increasing in the Ross Sea since the early 1980s, and why the increase has mostly been exhibited by smaller colonies. Although only about 13% of the Antarctic continental circumference, the Ross Sea contains about 38% of the 6 million breeding Adélie Penguins in the world, and 3 of its largest colonies (3 of 6 exceeding 120,000 breeding pairs). We know about this population increase from the frequent and, in some cases, annual counts being made of the colonies by biologists of Landcare Research New Zealand, using aerial photography. The reason it is taking us so long in this quest is that we need to accumulate the individual histories of known-age birds, acquiring information for each bird, such as year of hatching, year of first breeding, and subsequent breeding success. We also need to know the proportion of each age group that survives from one year to the next, and whether or not as young adults they return to the colony of their origin or move elsewhere (emigrate) to nest at another colony.

Important to this quest is the banding of chicks (with a metal band that has a unique set of numbers) at 4 colonies every year: Cape Crozier (150,000 pairs), Beaufort Island (45,000 pairs), Cape Bird (40,000 pairs), and Cape Royds (4000 pairs). Otherwise, we spend a lot of time walking, with binoculars in hand, looking for penguins wearing bands at those 4 colonies. They don’t first come back for a visit until they’re 2 years old, and they don’t begin to breed until, on average, 4 or 5 years of age. The penguins reveal their secrets slowly, and so we must be patient. We are pleased that folks at the National Science Foundation, which funds our project, are patient, too. In any case, we began this 12th year, leaving the USA on 4 Nov, arriving in Christchurch NZ on 6 Nov and then, after a few days of weather delay, arriving at McMurdo Station, Ross Island, on 11 Nov. While in McMurdo we attended courses on survival in extreme conditions, proper conduct in specially protected areas, and the proper disposal/recycling of no-longer-needed materials (cans, bottles, paper, metal, etc.). McMurdo saves for recycling about 80% of its refuse (the remainder goes in a landfill in the USA). During this period, too, we sorted through our field gear and acquired our camping gear from the Berg Field Center. We had to do this for 3 camps, all on Ross Island: Cape Crozier (a hut there), Cape Bird (a hut), and Cape Royds (a tent). We had at least a ton of stuff, including food.