One hot spot for mammal-hunting transient killer whales is mostly certainly a cold spot for everybody else.
I’m Lisa Strong for the Petersburg Marine Mammal Center.
Tidewater glaciers are rivers of ice that end in the ocean. A tidewater glacier’s terminus can be a wall of ice towering over the water. Calving ice cracks and tumbles off the face or shoots up from below the ocean surface creating a flotilla of icebergs in the water around it. LeConte Glacier, and Sawyer Glacier up Tracy Arm, are classic examples of tidewater glaciers.
If you’ve had a chance to pick your way through the icebergs around a tidewater glacier, you may have noticed a good number of shy harbor seals eyeballing you from atop chunks of floating ice, trying to decide if they should slip into the water now or wait two more seconds. Harbor seals haul out on these floating safe zones to rest, birth and nurse their pups, and to molt later in the summer. They’re generally safe when they’re on the iceberg. But in the water, things can get dangerous.
Volker Deecke is a researcher from the University of British Columbia who studies transient killer whales. He shares his take on why tidewater glaciers are a hot spot for transients.
DEEKE: So the seals are swimming up to these glaciers, the females pup there in May and then in June and July the pups are weaned and are starting to leave that area, so it’s an abundance of very young, fresh, tasty and very naive harbor seals and that my guess is that’s why these killer whales show up in these places.
You may also catch an occasional glimpse of transients closer to home — in the Wrangell Narrows, but for entirely different reasons. It’s a shortcut to travel north and south.
DEEKE: If the animals want to avoid any of the narrow passes, they have to go all the way around Kuiu Island, Cape Decision which is a huge detour, so it is quite normal that these animals should choose these shortcuts. Certainly, the boaters do it and the killer whales have probably been doing it for much, much longer.
