Even Further South - Adelie Penguin

Adelie Penguin (Pygoscelis adeliae)  Fish Islands, Antarctic Peninsula 2008

Penguin Kite Aerial Photography II

Here are some more aerial photos taken with my kite set up. This is one of my all time favorite photos I have taken with the kite rig, mostly because of all the Antarctic elements found in the photo. Along the left side of the frame, running top to bottom is the upper reaches of the nearby beach of Admiralty Bay on King George Island. There you can see the scattered whale bones left over from the whaling days of the last century. The penguin colony in the center of the photo is an Adelie Penguin colony. Above this colony is the scattered nests of a group of Gentoo Penguins. Notice the much tighter density of the Adelie Penguins - probably an adaptation to nesting where there is usually much less exposed rocks to nest on with the rest of the area around the nesting colony usually covered in snow. I suspect that this colony is no longer even active given the declines in Adelie Penguins this far north. Just to the right of center is a skua flying over the colonies, most likely a Brown Skua (Stercorarius antarcticus) or Catharacta skua, C. lonnbergi, C. antarctica and C. maccormicki - take your pick (skua taxonomy is rather scattered).

I am standing in the snow in the lower right portion of the photo.  The numbers written into the photo denote where I had markers place for GPS locations to be taken later.

The photo below is a much larger Adelie Penguin colony at the same complex of penguin colonies on King George Island near the small U.S. Research base called Copa.This colony was never able to be accurately counted prior to my work because it was so large. Any guesses as to how many nests are in this colony?

Another photo of a couple of smaller colonies at Copa. I am standing just in the photo on the lower left.

 

One day we dropped the camera low over a Gentoo colony to observe the reaction of the birds. As you can see from the photo, they did not appear to even notice the kite and camera over them. I like the patterns radiating from the nest sites.

Penguin Week - Adelie Penguin

The penguin week idea seems to have not only stretched out beyond the week, I am now into the second month of trying to get some Antarctic themed posts done. Here is the latest installment.

The Adelie Penguin (Pygoscelis adeliae), along with the Emperor Penguin is a true penguin of Antarctica. They only nest on Antarctic islands and along the continent where there is a 'just right" combination of ice and snow free breeding areas juxtaposed with areas of relatively consistent and nearby sea ice. Most of the year they are found living in the pack ice. They forage under the ice for krill feeding on the algea growing on the underside of the bits and pieces.






In early October they begin to return to their breeding colonies. In keeping with my one place-one penguin species concept I used in my previous penguin posts, I am going to talk about Adelies at Paulet Island, a fairly small island in the Weddell Sea just east of the Antarctic Peninsula. Here (PDF) is a good overview of this island with most of the information coming from Oceanites work. There is a great aerial photo of the island in this PDF that gives a good view of the extent of penguins breeding on this island. This is one of the landings where most visitors to Antarctica get to experience Adelie Penguins en masse. A number of these guidelines for other islands can be found here.









And what a mass of penguins it is. Paulet Island is home to about 60 to 100 thousand pairs (so the actual breeding population on the island is somewhere between 120 and 200 thousand individual birds). And those are figures from about 20 years ago and probably pretty wild guesses at that. I suspect that given the available space on the island and my perception of vacant colonies, it is probably still at least that many penguins if not more. It is very hard to estimate the number of birds without quite a bit of effort, but one of the things that Oceanites has been doing is trying to get good estimates of the number of breeding pairs at these large colonies by GPSing the colony boundaries for all the colonies on the island and then applying a density figure to at least get a better estimate than the good old ocular estimate, i.e. "we eyeballed it".





These are tough birds. They nest is very inhospitable conditions and seem to do quite well even when the weather is not very nice for penguin counters.






A rather small colony at Paulet.



This is a view of the main landing beach at Paulet from the top of a nearby bluff (also pretty well covered in breeding penguins). The dark mass in the middle is the remains of a rock hut built by Captain Larson and twenty men after their ship the Antarctic sank in heavy pack ice in February 1903. They spent the winter of 1903 on Paulet, eating penguin and seal. Larson and five of his men managed to get to (somewhat) nearby Snow Hill Island in November, where the Nordenskjöld expedition they were sent to rescue were located. You can read more about this expedition here.



Another view of some of the colonies on the beach at Paulet.



Adelies nest in rather dense, regularly spaced colonies.



A pair of Adelies at their nest on the Fish Islands. The bird on the right (which appears to be the female to my eyes because of the slighter build of the bill - but I am quite out of practice at determining the sex of a penguin so it is just an educated guess) has just returned from a feeding bout and is initiating a nest relief with her mate. Notice how clean she appears compared to the male on the nest. One of the most critical time periods in determining the fate of a nest early on in the season is the first nest relief when the female returns after a feeding bout she makes right after laying the eggs. If she is not back to relieve the male within 10 days (give or take a day) the male will abandon the nest so that he can feed too. By that point he has been fasting for about two months at the colony and has reached the end of his physiological rope.



Sometimes late snowfall can completely bury nesting penguins. It can impact the breeding success of some pairs when the incubating bird forms an ice bowl around it and the meltwater doesn't drain from the nest and kills the eggs. Although probably not as important as a driver in determining Adelie populations as the environmental conditions related to sea ice, the loss of a years breeding can contribute to population declines when it starts happening with greater frequency. Heavy snowfall during this time seems to be increasing in frequency as more of the ocean surrounding the Antarctic Peninsula remains free of ice, increasing the transfer of moisture to the air. As with most declines in animal populations, the cause is often not just one factor but a multitude of factors that influence survival of individuals and their ability to produce offspring.


Clicker in one hand and the other is used to mark my spot in the colony when I am counting.



We arrived at Paulet just as the chicks were hatching. Many of the nests still had eggs, but a good number also had small chicks about this size, probably about a week old.







We were also able to see a number of birds hatched the previous year on this trip, a sight many people to not get to experience. These birds are easy to tell from older birds by the lack of black on the chin. They attain that plumage after their first full molt when they are one year old. They rarely return to the breeding colonies at this age, but spend much of their time just trying to survive and attain the mass needed to attempt breeding. They are often found in areas of high krill concentrations where there is still sea ice. We found many of them south of the Antarctic Circle in Marguerite Bay where there was still a fair amount of sea ice.





This is a sign at the former British Antarctic base Faraday, now the Ukranian base Vernadsky.

Interesting penguins

About a week ago GrrlScientist posted a note with a photo of a penguin near Granholm Hut, Antarctica by Brett Jarrett that is lacking black pigmentation. It is not completely lacking pigmentation so it is not albino but the feathers that are supposed to be black are a creamy colored white. You can see the photo here. In the comments to this post, Tony Pym discuss the different terms for abnormal plumages, particularly those lacking normal black pigments. Tony also has a link in this post here where he has photos of a number of oddly pigmented penguins too.

As I noted in my comments to GrrlScientist, this is not an entirely rare event, probably made more obvious by their obviousness and the magnitude of the breeding population concentrated in one area making these anomalies more apparent.

I have found a number of odd looking penguins and penguin eggs in my work in Antarctica including a pair of Albino chicks about a year ago on Heroina Island in the Danger Island group in the Weddell Sea side of the Antarctic Peninsula. Here are some photos of those birds.


Note the lack of pigmentation in the bill.

Close-up of the eye of this bird. No pigmentation.

I also have a few photos of a pied chick I photographed on Torgersen Island near Palmer Station about 10 years ago and a King Penguin that has black feathers where the white feathers should be from South Georgia, and an emerald colored egg from King George Island but they are all slides or printed photos. I will post them here when I get them scanned.

Here are a couple of photos of a penguin that I photographed on Snow Hill Island in the Weddell Sea about 7 years ago. It was found by another guest onboard the National Geographic Endeavour and he showed it to me. He found it weathering out of a snowbank and it appeared to have been buried in the snow for quite a few years before being exposed. It looked like the remains of an Emperor Penguin to me.

More penguins

More recent penguin research documents the bio-accumulation of organic pollutants in the soil of Adelie Penguin colonies. As reported in the Journal of Environmental Monitoring, the authors found concentrations of persistent organic pollutants such as DDT, DDE, and PCB's 10 to 100 times higher in soils of penguin colonies than in nearby reference areas. Although these pollutants have been known in penguins, where they bio-accumulate from pollutants distributed to the Antarctic through long-range atmospheric transport from other areas, this research suggests that these birds further bio-accumulate these pollutants at their colonies through defecation. Thus, the soils around the penguin colonies are "hot spots" of persistent organic pollutants.

Other penguin items of note include this National Geographic video here with a couple of brief shots of yours truly counting penguins. This video is from two years ago when Boyd Matson accompanied us on the National Geographic Endeavour and it includes a number of the Oceanites researchers in the video. It is a fairly good if not brief overview on the current status of penguins on the Antarctic Peninsula.

Oh yeah, and one more thing. Those penguins that are occasionally reported off the Pacific coast of North America are probably unwilling hitchhikers from farther south. An article by A. N. Van Buren and P. Dee Boersma in the Wilson Journal of Ornithology examined the occurrences of penguins north of the equator (excluding the Galapagos Penguin which nests on Isabella Island in the Galapagos just north of the line). Although penguins are known to move very long distances (I once found a Magellanic Penguin, which normally breeds in southern South America, near Palmer Station on the Antarctic Peninsula), these movements are all within cold or cold waters of the southern hemisphere. They argue against natural vagrancy for the northern observations because a penguin would likely overheat in the equatorial waters before finding cold waters north of the equator.
The authors explain that the occurrences of these birds is probably due to intentional capture and subsequent release by fishermen moving from the cold southern waters to the cold northern waters and provide information on a number of penguins found on fishing vessels in northern waters.

Laurence Roosens, Nico Van Den Brink, Martin Riddle, Ronny Blust, Hugo Neelsa and Adrian Covaci. 2007. Penguin colonies as secondary sources of contamination with persistent organic pollutants. Journal of Environmental Monitoring 9 pp. 822-825.

A. N. Van Buren and P. Dee Boersma. 2007. Humbolt Penguins (Spheniscus humbolti) in the Northern Hemisphere. The Wilson Journal of Ornithology 119(2)284-288.

Penguin Interlude Part II

A paper in the Proceedings of the National Academy of Sciences by Steve Emslie and William Patterson recently prompted a New York Times article and mention in the Querencia blog.

This paper discusses changes in Adelie Penguin diets over the last 38000 years by examining eggshell remains found in detritus of historic and present Adelie Penguin colonies. The stable isotope values of carbon and nitrogen in over 270 eggshells suggested that there was an abrupt shift in the diet of Adelie Penguins throughout their range from fish to krill about 200 years ago. The change in diet coincides with the discovery of the Antarctic Peninsula and subsequent exploitation of the Antarctic Fur Seals in the area.

I will provide a bit of the back-story on this paper. Sealing began in the sub-Antarctic islands in 1784 and on the Antarctic peninsula in 1819 although sealers were probably working the peninsula before that but not giving away the location of their hunting grounds (you thought it was an untouched, pristine continent didn't you - just wait). During the 1820-21 austral summer 55 to 60 sealing ships were in the South Shetland Islands and they took an estimated 1/4 million seals in 3 months. Millions of seals had already been killed in the Sub-Antarctic islands and by 1825 the seals were gone and the Antarctic Fur Seal was believed extinct.

Antarctic Fur Seal on whaler's cross. South Georgia.

Whalers came next but the harvest of whales and whale-like seals was limited to the slower more accessible species such as the Southern Right Whale and Elephant Seals. By the early 1900's however, with the advent of the explosive harpoon and faster ships, the rorqual whales which were previously too fast to catch became the preferred target. Shore stations for processing whales were established in 1904 on South Georgia and by 1910 about 12,000 whales were harvested. In 1926 the first floating factory ship began working in the Antarctic waters. Nearly 30,000 Blue Whales alone were killed during the 1930-31 season. Blue Whales, Fin Whales, Sei Whales and Minke Whales were harvested in turn and in 1940, 40,000 whales were killed. (See here for more history and here and here for more historical whaling information).

The above graph shows the numbers and species of whales taken in Antarctica from 1904-05 to 1980-81. See here.

In 1985, Richard M. Laws, then the head of the British Antarctic Survey, published a paper in American Scientist entitled "The Ecology of the Southern Ocean". In his paper he estimated that whales, a pre-harvest biomass of nearly 45 million tons, had probably consumed 190 million tons of krill in addition to 14 million tons of squid and 5 million tons of fish each year. He further estimated that my 1973 the whale biomass was about 9 million tons and they consumed 43 million tons of krill. This left a "surplus" of 150 million tons of krill annually (italics are mine). He surmised that this surplus had a profound affect on the ecology of Antarctic animals and in particular had increased populations of Adelie, Chinstrap and Macaroni Penguins. In addition, during this time the Antarctic Fur Seal reappeared from the mist of extinction and prospered in the absence of the large whales. They probably now exceed their pre-exploitation population. His premise certainly seemed logical.

However, in 1992, a host of Antarctic researchers then affiliated with the Point Reyes Bird Observatory, published an article in Polar Biology suggesting that the krill surplus theory was not responsible for changes in penguin populations at all. The title of their paper, "Increases in Antarctic penguin populations: reduced competition with whales or a loss of sea ice due to environmental change" suggested it was an either/or proposition and that they believed that much of the observed changes in penguin populations were not due to reduced competition for food but were instead a result of changes in the amount and duration of Antarctic sea ice. They provided very compelling evidence that the amount and duration of sea ice had more influence on the relative populations of Chinstrap and Adelie Penguins than the surplus of krill.

So where does this recent evidence of a shift in Adelie Penguin diet from fish to krill during the time of heavy exploitation of krill eating animals leave us?

I began my Antarctic penguin studies during the time of the sea ice theory and in fact I had two of the authors as advisers at one time or another. But I was never comfortable ruling out the impact of the removal of that many whales. I just couldn't believe that the loss of that much krill-eating biomass didn't have some affect on the ecology of the animals I was studying. In a sense, Emslie and Patterson's work vindicates my uneasiness. They noted that the switch from fish to krill coincided with the presumed krill surplus and supports the krill surplus theory. They also noted the proponderance of krill in the modern diet of Adelie Penguins is relatively recent phenomenon.

Although this work does support a switch in diet from fish to krill and suggests that the krill surplus may be responsible for this shift, it does not address the fundamental premise in either the krill surplus or sea ice theories for changes in penguin population- that there was a change in penguin populations as a result of the shift from fish to krill.

I believe that all of these factors have impacted penguin populations in one way or another. The physical environment and changes in sea ice extent do have an impact on penguin populations through the availablity of krill to both adult and recently fledged penguins and they affect species differently depending on their dependence on the sea ice environment. I also believe that there was a profound affect on penguins and other Antarctic animals as a result of the loss of the Antarctic Fur Seals and great whales. These factors have interacted and continue to interact in subtle and dramatic ways to influence the distribution and abundance of Antarctic and Sub-Antarctic penguins today.

Steven D. Emslie and William P. Patterson. 2007. Abrupt recent shift in δ13C and δ15N values in Adélie penguin eggshell in Antarctica. Proceedings of the National Academy of Sciences 104(28)pp 11666-11669.

William R. Fraser, Wayne Z. Trivelpiece, David G. Ainley, and Susan G. Trivelpiece. 1991. Increases in Antarctic penguin populations: reduced competition with whales or a loss of sea ice due to environmental warming? Polar Biology 11:525-531

Adelie Penguin colonies from the air. Note the nice pink color of the colonies. Photo by Ron Naveen (Oceanites).

This is where the color comes from - lots and lots of penguins in one spot all digesting large amounts of krill and depositing the remains.

Over many years this forms a layer of ornithogenic soil (old bird shit). Within this layer are old egg shells and concentrated organic pollutants - see here.