Cape Sherriff Cont.

What goes on at the station?
Some of the scientists research penguins, others research fur seals. I was able to watch Mike in action as he weighed a fur seal pup (8.6 kg!) that was almost 3 weeks old. Mike has spent field seasons at Cape Sherriff annually since 1986, and has seen some interested changes in populations during his 28 years here. For example, 15 years ago there were about 10,000 fur seal pups on the island each year. This year that number is just 2,000. What’s changed? Predatory leopard seals have begun feeding on the pups as they venture into the water and learn to swim. The fur seals evolved in an environment without an “apex predator”, meaning they didn’t evolve around animals that ate them. Now they have a predator but no natural defenses against it.


Mike and the fur seal pup he just weighed.

What makes leopard seals change where they eat?
Leopard seals have started feeding at Cape Sherriff because their usual meal (Crabeater seals, which eat mostly krill and not crab) are no longer as abundant in this region. Those seals require sea ice to breed, give birth, and hide from leopard seals; with warming global temperatures the sea ice has disappeared and so have the penguins. The leopard seals, who have a reputation for being aggressive hunters, have moved on to the next most available food source – fur seal pups.

What was it like to see the seals up close?
It was awesome!
Surprisingly, the seal colony didn’t smell too bad.
The fur seal pups were absolutely adorable.
The males were only protective of their harem of females; the females were pretty nonchalant about us walking so close to their pups; the pups liked to growl at us and bark, which sounded a lot more like belching than barking. Mike told me that most fur seals are more wary of humans, but because the adults in this particular colony grew up with him around they aren’t scared of him. There was one female he pointed out, though, that he said was kind of mean and often tries to bite him – we gave her an extra wide berth!


A male fur seal adult (L) and 3 of his female mates. The dark brown pup in back is nursing!

While I was the only guest on the VIP tour, the rest of our science party from the R/V Gould also had the option to go ashore, lend a hand, and see some of the wildlife. My roommate and research partner for the trip - Dr. Jessica Fitzsimmons (Rutgers) – filmed a short clip of some Chinstrap penguins on the Cape. It isn’t long, but we’re floating in the middle of just about nowhere; the fact that we have enough bandwidth to get a clip on the internet is pretty exciting to the two of us!