Update #4
12 - 24 January 2003

The past two weeks have been filled with more trips in the field, including an overnight stay at a field hut, surveys of more islands and the continental margin for abandoned colonies, and lab work.  We have now completed excavations of 11 abandoned colonies near the station. Though there are many more here (70 have been mapped), we will not sample any more in this area.  Each site has been similar in terms of the sediments and geology, but all have differed in how much organic remains have been recovered. Some sites are rich in bone, eggshell, and other remains while others have few or no bones, and only a little eggshell.  The differences in preservation may be related to the age of the sites, but we will have to wait until the analyses are complete to know for sure.

After completing excavations near the station, we began to check other areas.  We returned to Robo's Hut, on Robinson Ridge, a few miles south of the station where we had our field training shortly after arriving here.  At that time, I had noted some abandoned colonies near the hut. Now, we were dropped off at the hut by zodiacs after an hour and half boat ride through pack ice that drifted back into our bay due to a recent change in wind direction.  The ice brought in more wildlife, though, and we saw a Weddell seal as well as penguins on the ice floes.

An Adélie penguin and Weddell seal share an ice floe.	Weddell seal sleeping on an ice floe.

Excavating a site at Robinson Ridge. Robo's Hut is on the ridge in the far background.

At Robo's, we sampled one site near the hut, but found little eggshell and no bone in the sediments.  So, this site might be older than the others, or the preservation may not be as good because of more ground drainage (more water flowing through the site due to it's location on a slope).  Near the site, we also found a ventifact, or a large boulder that had been carved and polished by wind-blown sand, and a nice bed of moss in a low wet area.  After spending one night at the hut, and enjoying the relatively warm weather there, we returned to the station for more lab work.

A ventifact on Robinson Ridge.	Steve enjoying a 'warm' sunny day during a break at Robo's Hut.

A moss bed on Robinson Ridge.	Close-up view of the moss.

On another day, we visited Peterson Island, farther to the south of Robinson Ridge.  Again we went by boat and this island has a small 'apple' hut for people to use (see photo in the photo album).  This island is quite beautiful with its hills and ridges, coastline, and small melt lakes tucked between the hills.  Two young male Southern Elephant Seals were lulling in the sun on the beach where we landed.  In addition, there are some large active penguin colonies here as well as lots of abandoned sites.  In fact, over 140 abandoned sites have been counted on this one island alone, an impressive number for a relatively small area.  It's beginning to look like there are hundreds of abandoned sites in this entire region, more than I've ever seen in any other area of Antarctica.  Why?

A young male Southern Elephant Seal on Peterson Island.	Abandoned penguin colonies surround a small lake on Peterson.

An Adélie penguin colony on Peterson Island.

It's possible that the Adélie penguins are moving from colony to colony here more than they do in other regions.  In the Antarctic Peninsula and Ross Sea, we know from long-term studies of banded birds that a nesting pair will use the same nest every year.  The male will return first and will keep coming to the same nest site year after year until he dies. Rarely do they move to a new site.  It's possible that this behavior is not the same in the Casey region.  Dr. Eric Woehler, my colleague who has been studying penguins and other seabirds in this region for many years, has shown me photos of penguin colonies near Casey that were taken in the late 1950s.  Photos of the same areas today indicate that many colonies that were active in the 1950s are abandoned today, while new colonies have developed nearby.  Normally, when colonies are being abandoned it means the population is in decline, but here the penguin population is increasing.  So, there seems to be something different happening in this area and if the penguins are moving to new nest sites and new colonies every few years, that might explain why there are so many abandoned sites in this area.  All of this is just speculation at this point--it will take additional research and more work in this area to fully understand the situation here.  Research often leads to more questions and more research and that's how the field of science grows, as does our knowledge.