The three types of killer whales. From R. Pitman, P. Ensor, J. Cetacean Res Manage 5(2):2003.

Ross Sea killer whales appear in the McMurdo Sound area and the southern Ross Sea, in early December and ply various fast ice edges (ice attached to the land), which as the season progresses recede further and further south toward the continent. They also apparently forage under or along the edge of the Ross Ice Shelf by Cape Crozier on the other side of Ross Island. These whales feed on fish that live under the fast ice and as the ice recedes the whales are able to exploit more and more feeding territory. Sightings of these whales, from land, helicopters and ships have been carried out through the years, most recently from the Cape Crozier and Cape Royds penguin colonies on Ross Island, where it has been noticed that the presence of whales (including minke whales) follows a shift in the diet of the penguins.

Killer whales foraging in a sea ice crack.

In 2005 the ratio of C to B killer whales was 50-1, but over the next few years it steadily dropped to 16-1 by 2008. As the observed numbers of B whales (seal eaters) did not change during this time, the altered ratio was due to the decrease in Ross Sea killer whales. During the years of these observations another important series of events was taking place.

Although commercial fishing of the Antarctic toothfish (sold as “Chilean sea bass”) in the Ross Sea began in 1996, it was expanded in 2004 from 9 to 22 fishing vessels; not surprisingly that same year the catch reached its allowed limit of 3500 tones. These boats target the largest adult toothfish, which is the same size those taken by the whales. Toothfish are a slow growing species which do not reach maturity until 16 years old. Many of these fish taken in the fishery were over 25 years old, some older.

Antarctic toothfish.

Since 2004, the commercial catch has remained steady year by year. Catch and release efforts of toothfish by scientists in McMurdo Sound remained steady from the years 1974 to 2000, but dropped 50% in 2001 a few years after the commercial fishing began and then to 4% in 2007, only 3 years after the peak commercial catches began. It would appear that the drop in Ross Sea killer whale numbers is related to the increase in the commercial fishing of the toothfish.

Are there any other animals that would be affected by the reduction in toothfish numbers?

Weddell seals also take toothfish as a primary food source and their numbers have not decreased in McMurdo Sound, though trends elsewhere along Victoria Land are unknown. Seals are able to dive deeper and stay under longer than the whales and therefore able to catch the fish which are safe from the whales. Seals therefore not only forage where the whales forage, but also in areas the whales can not reach, places covered with extensive fast ice where small cracks provide breathing holes. Seals also eat silverfish. It is thought that whales also eat silverfish but there are no confirmed sightings for this. The whales therefore may be more sensitive to changes in toothfish availability. If the toothfish industry continues to extract the current yearly numbers, it is predicted these creatures will decline more rapidly.

For more information about the Ross Sea, the toothfish industry and how it is affecting penguins, whales and seals go to The Last Ocean.

South Polar Skua.

This large aggressive bird is an opportunist. When the seals haul out on the ice and give birth to their pups the Skuas hang around and eat the after birth. At McMurdo Research station they will wait for people to leave the dining hall with a sandwich or cookie in their hand and swoop down for the ‘kill.’ When it’s time for them to breed many build their nests at the edge of penguin colonies where first the penguin eggs then the chicks can be easy pickings among the penguin parents who are just beginning.

Skuas, tag teaming a penguin to get the egg.

Adult Adélie Penguins can defend themselves so are safe from Skua attack. However, while the penguins are nesting, and before the Skuas lay their own eggs, the Skuas work in pairs, one will fly overhead to distract the Adélie and the other will swoop in and snatch the egg or chick as the penguin stretches to peck at the decoy. Often times when I’ve been sitting watching this, I wish that the penguins would someday take revenge.

The Skuas often build their nest close to the Adélie breeding colony so they do not have to go far for their food. But in the following sets of pictures you can see this Skua was very bold, laying the egg within 10 feet of nesting Adélies. At first the Adélies would walk by with only passing interest in the nesting Skua but finally one penguin decided this was too close and challenged the Skua.

A Skua nest very close to a group of Adélie Penguins.

Some penguins would walk by without paying attention to the intruder.

First a challenge.

Then the Skua is evicted from the nest.

Every attempt by the Skua to return to its nest was thwarted by the penguin.

Finally the egg was lost to other Skuas.

Skuas are no match for adult Adélie penguins so the Skua moved off the egg. The penguin did not chase the Skua but stood at the nest and did not allow the Skua to return. Every attempt by the Skua to return to the egg was thwarted, and meanwhile the Skua egg was getting colder by the minute.

Skuas are indeed opportunist eaters. Even exposed Skua eggs are taken. This egg was no exception and once the penguin walked off, with in a few minutes another Skua made this egg its meal. The Skuas abandoned this nest site and will likely build one a much safer distance away next time. Penguins 1 – Skua 0.

Penguins sitting on eggs. In the right-most picture the very busy mate has continued to bring rocks to the nest, to place them on top of the snow.

When storms come the penguin will not leave their nests. To do so would mean their eggs would be blown away or freeze very quickly. During the storm they sit quietly with their face to the wind and wait for it to be over.

Adélie Penguins seem to have a strong sense of where their nest site is even if it is covered with snow! For this group, their sites from last year are under 3 feet of snow. Not discouraged, they simply built their nests on top of the snow pile. How this will affect the egg and chick brooding, hatching and rearing as the snow melts, we are going to find out.

This pair returned to find their long time nest site covered with snow. Instead of building on top of the snow they decided to move elsewhere and found a cozy nest site with a couple of large rocks for protection from the Skuas about 12 meters away. This is nest #3 in our Nest Check and you can follow them throughout the breeding season by seeing the daily pictures here.

Because of their body heat some of the birds are sinking into the snow pile as the days go by. This bird, below, built his nest on top of the pile, but as you can see he is slowly sinking into a larger and larger hole. He is on a nest of a few rocks with two eggs under him. When the female came back it was a challenge to do the nest exchange. We will observe and record the success of this nest.

When the sun comes out and the snow melts, there are small streams everywhere. Small depressions (scrapes) where penguins have built nests in the past fill up with water. This makes it harder to build the nest and the penguins need more rocks. A successful nest will be high enough to keep the egg out of any water run off. The egg will not hatch if it is sitting in freezing water.

The penguins on the left have a challenge to build a dry nest above the water. The third picture shows the result of a poorly built nest in the mud. The egg rolled out and moments later it was picked up by the ever watchful Skuas. The nest shown to the right is a well built nest above the mud, these eggs will be kept dry.

Adélie Penguins are sturdy birds, but stronger and more summer storms pose a challenge to their breeding success. Read how these birds are coping with the effects of climate change here.

Satellite image of McMurdo sound and the ice cover, Nov 2008, (left) vs. Nov 2009 (right).

At Cape Royds we have a ‘penguin cam’ which is a permanent structure housing a remote camera. The camera takes a picture of the colony every day as long as the solar panels generate the power to keep the batteries charged. Since the research team is not in the field all year round, this allows us to monitor what is happening at the colony when we’re not here. You can see the daily pictures at http://penguinscience.com, as well as a time-lapse of images taken over the last two years. Last year and this year the first penguins were seen the last week of October, so not much changed there, but there were fewer birds and nests being built during the first weeks this season. When we started looking for eggs the picture became even more surprising.

In 2008 the first eggs were seen on November 5th. This year we did not see eggs until November 16th. Plus the number of birds present in the colony continued to stay low. Something was keeping the penguins from arriving, building their nests and laying their eggs on the normal schedule. As the days progressed more birds started showing up and by November 25th the colony looked busy, with many nests completed and females leaving for open ocean to replenish their energy and become fat again.

An early arrival at the colony. He could have all the stones he needed so he built a large nest. Now he waits for the female to show up and guards his rocks from other males as they arrive.

The breeding season in Antarctica is very short. Adélie penguin chicks must gain the weight they need to sustain themselves through their molt to adult plumage before they are able to swim and find their own food. If the sea ice closes in around Ross Island before this happens they will have a huge task walking to open water and food. They can not swim until they have their adult plumage. We do not know what will happen this season, but that is why we are here so we can observe and record this event. We are hoping you will follow along as well.

Did you know that penguin researchers also use the satellites to track penguins when they are out in the open ocean foraging for food? See how they do this here.

Learn more about Adélie penguins at www.penguinscience.com

As part of the AMLR cruise, we visit the field camp, ferrying both researchers to and from the island and also bringing them supplies like fresh fruits and vegetables which they otherwise would have no access to. The research team lives at Copacabana from October to March studying Gentoo penguins, as well as Chinstraps and Adelie penguins, Giant Petrels, Skuas, Fur Seal and Elephant Seals. Here I share a bit about the gentoos specifically and their amazing life cycle.

Catching them means we use a corral to surround the crèche and then move in hopefully herding them into the pen. Stepping inside the pen, we sort out any adults that were caught by mistake, then the smaller chicks we will not band. Now the work begins. Catch a chick, hold it between your legs, place the hard metal band around its wing and press it closed. It is very important to make sure the ends of the band are flush and together otherwise the band may interfere with the swimming ability of the bird.

This pen is used to catch the chicks. We get inside and sort out the adults and small ones, then band the big ones.

Banding the chicks. It’s important to get the band on exactly right, otherwise it will interfere with the birds swimming.

We now say good by to these chicks, leave them alone to finish their molting and find their way to the open ocean and food. Many of the adults have already left, these chicks are on their own.

These chicks have been banded. It may be two or three years before we see them again.

The adults have left these chicks to finish molting on their own.

It’s hard for us to say goodbye. The pile of equipment is the last load of the season. Our amazing helitech solves the puzzle, and still there is room for all five of us. We are covered in penguin guano, feathers and dirt after a day of banding, but feel good as this last task of the research project brings this season to an end.

The last trip of the season. All this equipment must fit into the helo, and the five of us too.

All that equipment made it; now we have to get in. It is goodbye to Cape Royds for the winter.

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.

We heard that sound again two days ago at Cape Royds, having heard it before in January 2005, when a several square kilometer opening appeared in the fast ice just offshore in a matter of hours. The ice was dissolving, or would we call it melting?, and it was happening so fast that you could see it disappearing without even needing your imagination to be going overtime. It’s kind of like putting an ice cube in a cup of boiling tea water to watch it disappear; only here the water is just a degree above freezing. That’s plenty warm as ice goes. In 2005 the fast ice was thinner, so it went from white ice to blue water; this year it was much thicker, so for a couple of weeks it slowly turned darker shades of gray, as it took on more water. Then, fzzzzzzz.

Otherwise, except for this new patch of open water within the ice, called a polynya (a Russian word; without a doubt the Inuits have a name for this, too), there is still fast ice to the horizon as I have described in various of my previous dispatches.

The Swedish icebreaker Oden going south, very slowly, through the ice a few kilometers out in McMurdo Sound, while a polynya begins to form next to Cape Royds.

The south ‘shore’ of the polynya, the day after it initially formed, showing proximity to the Cape Royds penguin colony (tan area on left side of image). The polynya is to the right, beginning to dissolve the gray ice in the center of the image.

In fact, in the Arctic, Inuit villages — and, for that matter, seabird colonies — are located near to polynyas. And, wouldn’t you know, so are penguin colonies, although at the opposite end of the Earth. This is because polynyas allow these predators much easier access to their food. Normally, McMurdo Sound is one big polynya, and the penguins are here at Royds because of it. As I’ve been making the point in previous dispatches, the Royds penguins have been having a hard time of it this season, because their polynya didn’t form, owing to calm winds which allowed the ice to thicken until not even the strongest winds could blow it away. So, they’ve had a very long walk to get food. That is, up until a few weeks ago, when the few remaining penguins still having chicks were provided a large crack to feed in, just 4-5 km north of the colony. Now they’ve got a full-fledged, mini-polynya and all is right in the World!

Well, just like in 2005, within a day of the polynya forming, a couple of minke whales showed up in it! Where they came from, I’m not sure, but they may have followed the Oden into the ice (35 km from the fast ice edge), and then pealed off when a crack that intersected the icebreaker channel allowed them to get to the Cape Royds polynya. Maybe they heard it fizzing! Or the sounds of joyful penguins!

The minke whales, for several hours, cruised around the polynya feeding all the time. They’d submerge for 6-8 min at a time and likely were like big “Hoovers”, i.e. vacuum cleaners. Between dives, they exhaled (i.e. whale “blows”) 4-5 times, clearly audible in the still air from a kilometer away. Within a couple of hours after the whales’ arrival, the penguins’ diet switched from krill to fish. I’d been monitoring it by watching what passes between adult and chick everyday for the past few weeks. Wow! I knew that the whales could do this to the penguins, but I didn’t realize that the whales were so efficient! Not long after the whales left (they’ve not been seen for about 24 hours now) the penguins’ diet switched back to krill. Therefore, this is pretty good evidence for what we call “interference competition”. The whales certainly eat a lot but also their vacuuming causes the krill to try to escape, of course. And what krill do when being pursued, if they can, is to dive deeper and, it seems, deeper than penguins want to go, especially when there are enough fish to be had at shallower depths, though apparently not in a density that in this case would interest a minke looking for easy pickings. If the whales had vacuumed all the krill, when they left, there would be no food for the penguins. As it was, the krill ventured back up into the light (where the phytoplankton occurs that the krill eat), to then be caught by the penguins again. Both whales and penguins go for the easy meal, i.e. that nearest the surface.

Parent feeding its chick. With binoculars, if you get the right angle, usually it is possible to determine whether krill (pink) or fish (gray) is being fed to the chick.

Well, so, you’d think that maybe whales are an annoyance to Adélie penguins. As it turns out, though, minke whales are life savers! Adélie penguins, if given a choice, would always want to have minke whales around, despite the whales’ appetite and despite the best (?) efforts of the Japanese whalers. You see, minke whales — because, like Adélie penguins, they are pack ice denizens — have evolved a very long and sharp “beak”. When you see the whales in areas were the sea is freezing, it becomes quickly obvious why this is a good thing. The whales use their rostrum to break breathing holes in the new ice.

This ice is thick enough that penguins walk over it. With the whales around, though, the penguins can swim between whale breathing holes much faster than walking. In fact, several years ago, when on an icebreaker at the time of ice freeze-up in the Amundsen Sea, one day there were whales and penguins swimming around, and then the next day, with a dramatic drop in temperature and a freeze, there were whale holes but no whales or penguins. Together, they had escaped north far enough to move away from the area of freezing.

A minke whale pushing up through recently frozen sea ice, the ice around it being 4-5 cm thick.

All but one of these penguins found a hole left by a minke whale; the next whale breathing hole is just behind the lone penguin and this flock of penguins is next going to appear in that hole.

These penguins are not walking on frosted glass. They are walking on ice thick enough to support their weight, but not thick enough that a minke whale could not break a hole.

It is good for Adélie penguins to have as many minke whales around as possible. This one, like the pied piper, is making a “channel” through new ice, soon to be followed by a flock (school?) of penguins, who would much rather swim than walk.

Penguins need whales, especially minke whales, as friends.

The trip was a roughly one hour ride over the sea ice in a dual-tracked vehicle called a MATTRAX.

Mount Erebus from the sea ice.

John Weller, our guide Peggy Malloy, Ron Hipschman and the MATTRAX.

During the trip we could see a few icebergs which were trapped in the sea ice.

What they do at the Penguin Ranch is study emperor penguins. They take a small number of emperor penguins from the coast and put them in a fenced in area on the sea ice. A couple of holes are cut in the ice for the penguins, and the penguins are then able to go swimming any time they want to (they catch their own food). The penguins apparently go diving around once an hour. There are no holes in the ice nearby, so the penguins always come back to the Penguin Ranch when they are done swimming.

Penguin Ranch.

The very beautiful emperor penguins.

A penguin at the start of a dive…

… and jumping back on top of the ice.

The best part of the Penguin Ranch was the observation tube. You can climb down in a narrow tube about 15 feet under the ice and look out some windows. The colors under the ice are amazing, as you can see! It was incredible to be under the ice and also to watch the penguins swimming.

Emperors swimming.

Thanks John and Ron and Peggy for a great day!