Friday, November 12, 2004

Pup tally = 152 (143 stil alive, 9 dead)

We have now tagged the majority of new pups for the season - only a few more will be born between now and when we leave in mid-December. We have also begun our series of population surveys for the season. On Wedensday, 4 of us went out on snowmobiles and covered the entire Erebus Bay study area, recording every single seal that we saw. Jay and Jim checked the coastline from Cape Evans down to the North side of the Erebus Glacier Tongue, then visited each of the Dellbridge Island colonies, finishing up at Big Razorback. Terra and I rode down the the southern tip of the study area and recorded the group of seals that hang out in front of Scott Base, the New Zealand research station. We headed north and recorded all the seals between Scott Base and the southern side of the Glacier Tongue. The total number of seals seen that day was 325 - many fewer animals than usual. Some of our surveys last year recorded over 1000 seals.

Yesterday we took an exploratory helicopter flight north of our study area to see if there were any large aggregations of seals in areas that may have been more accessible for pupping than Erebus Bay due to the ice conditions this year. We didn't see any groups of more than 2-3 seals, but the high winds kept us from flying as far north as we had hoped. Instead, we crossed over to the west side of McMurdo Sound and landed the helicopter near a large group of seals by a frozen-in iceberg. Tidal cracks form around the iceberg, creating an area for seals to haul out. We saw a few tagged females there, and so we tagged their pups in order to keep track of reproduction for the seals that are already a part of our database. Most of the tagged seals we saw had been originally tagged in that region (i.e., outside of our main study area). One female, however, was tagged here near Cape Evans in 1989 as a yearling, and hadn't been sighted since then, so that is of interest to us.

Our group getting ready to load into the helicopter

Some seal taggers walking back from the iceberg colony

Seals in Erebus Bay, with Mount Erebus in background

A glacier at one of the seal colonies

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