Tuesday, October 30, 2007

Penguin Colonies - Part 1

Two factors that can affect the stability of the emperor penguin population include stable sea ice and food availability. Both of these factors are subject to environmental changes and to human perturbations. Jerry Kooyman and Paul have monitored the populations at six of the seven colonies in the Ross Sea since the mid-1980s.

Cape Colbeck, located far to the east of Ross Island along the Ross Ice Shelf, has rarely been visited for censusing. Ironically, I understand that at least one passenger expedition goes there.

As an aside, having boatloads of tourists in the Antarctic is a really bad idea. Antarctica is too fragile an ecosystem to have tens of thousands of tourists tramping around it. Unfortunately, this type of travel is increasing exponentially each year.

In 1990, the colonies had the following chick populations: Cape Roget – 6,921, Coulman Island – 27,930, Cape Washington – 23,379, Franklin Island - <2,000, Beaufort Island - <2,000, and Cape Crozier – 324. Recently, both Beaufort Island and Cape Crozier colonies were devastated by iceberg B15 and its fragments.

We want to monitor the recovery of the two colonies disturbed by B15 (Crozier and Beaufort). We also continue the census of the four other nearby colonies to determine the general trends in the emperor penguin population in the Ross Sea. Paul, Cass, Jessica, and Cory went by Twin Otter (see below) today to three colonies, while Matt and I and two volunteers from McMurdo held down the fort at Penguin Ranch.

Paul and Cass are in front of the Twin Otter. The Twin Otters are a Canadian company. Each year they fly down to McMurdo from Canada to the tip of South America, and then, cross the Antarctica by way of the South Pole.

Here is an aerial view of Cape Washington, which is one of the largest emperor colonies in the Antarctic. From the air, this vast colony looks like a series of smudges. There are numerous sub-colonies at Cape Washington, as you can see.

Here is an aerial view of Franklin Island, which is a much small emperor colony -- more "smudges".

And, finally, here is the Beaufort Island colony, which this year is again situated near a small iceberg on the sea ice close by, rather than by the island itself. As was previously mentioned, this colony was hit hard by the massive iceberg B15 a few years ago. Most of the chicks of the year died, probably because the adults had a rough time reaching the open water to go hunting for food. However, unlike the Crozier colony, the adults didn't die. Once the huge iceberg left the area, the colony came back to its pre-iceberg levels.

This an interior shot of the Twin Otter with Paul, Jessica, and Cass.

Cory in the back of the Twin Otter is below.