18 November, 2003

This morning's Pisten Bully commute to Tent Island was delayed for a few moments by a seal lounging on the road. Once she moved, we were able to proceed with the day's photography and weighing mission. We selected 6 pairs of moms and their pups to photograph and weigh as well as a few pairs that still needed weighing since they had been photographed the previous morning.

By the end of the day we had photographed all the pairs and managed to get 4 of the 6 mothers to slither onto the scale. One of the pups was the official 'chubby puppy' of the season thus far, weighing in at 94.5 kg. He was somewhere between pup and seal in appearance, with new patches of smooth adult fur mixed with his soft lanugo puppy fur.

Most of the pups we are seeing now are getting big. A lot of them are spending more time in the water swimming with their mothers. Some of the oldest pups are only 10 days off from weaning and being on their own, since weaning occurs around 40 days after they are born. By the time these pups are weaned they may have tripled their birth weight. That's pretty impressive work in only 6 weeks!

Gillian took time today to look up some information on the seals we saw yesterday during our trip across the bay. Of the 6 tagged adult seals at Marble Point, two had been tagged right there, two out on the ice between our study area and the Marble Point side of the bay, and two had been tagged within our study area at Tent Island and Turk's Head. One of the Marble Point seals had been tagged in 1997 and the other in 1998. The seal that had been originally tagged at Tent Island had been tagged in 1998, while the male from Turk's Head had been tagged as a pup in 1986 (17 years ago!). The two females that had been tagged out on the ice had both been tagged in 1997. So what can be concluded from this very small sample? Primarily, this reinforces the notion that seals can and do move around within Erebus Bay and between colonies. Since our study is focused on overall survival we don't check the database after each re-sighting to see where or when parcticular seals were last seen-we are more concerned with collecting data on whether they are alive than on where they are living. It might be an interesting exercise to plot the movements of some of 'our' seals through the years.

Daily Haiku:

Chubby puppies lounge

Losing their long baby fur

Growing adult coats

Perhaps we need to establish a few 'seal crossing' zones along our route to Tent Island.

This is the image we get when we photograph a seal from the top. The scale stick is held next to the seal parallel to her widest point and is marked in 20cm increments. The ideal shot is taken when the mother is stretched out on her side with her top flipper at mid-body. This female weighed 316kg.

The seal pup in this picture is the official 'chubby puppy', weighing in at 94.5 kg. He's still smaller than his mother, but looks much more seal-like than he did in the first few days after he was born.

This is the pup that belongs to the mother in the previous photo. Pups are photographed when they are lying on their stomach, with the scale bar held off to the side. He weighed 33 kg.

This is the baby of the female in the previous picture. He is almost in perfect position--it's best if you can photograph them when their rear flippers are straight out from their body. Sometimes, however, you just have to take what you can get! He weighed 61.5 kg.

This is another image of an adult taken from the top. She weighed 420 kg.