I’m working on a roundup post about the farm visits/fleece buying, indigo dyeing, and general craftiness that I got up to whilst home on my last break from the boat, but when I sat down to start writing I found myself thinking about killer whales instead (probably because we’ve been seeing so many of them later).
One of my favorite things about working on the Sea Lion is that on quiet days I can listen in on the talks given by our shipboard naturalists. The naturalists rotate through according to their own irregular schedules, sometimes staying from two weeks, sometimes for six, and they often get to work on the other Lindblad boats as well, meaning that they also spend a lot of time on the Explorer (which travels to Antartica and Greenland amongst other places) working with other scientists and naturalists. This makes for a very free exchange of research and information mixed with experience, depending on the interests of the naturalists in question; a sort of ongoing informal conference.
It feels like every time a new naturalist gives a talk some piece of my world changes just a bit. We have been seeing lots of killer whales in the last few days, so I thought I would share what amounts to my notes from a talk given a few days ago. Apologies to Mike G. if I get anything wrong.
In addition various scars and life wear, individual killer whales can be identified by the saddle patch just behind their dorsal fin. Researchers have been using this ability to recognize individuals and figure out who is related to who and where they go, in addition to all the other useful things one can do once one can track individuals. For instance, on Tuesday as we left Petersburg we came across a group of killer whales that, using photos of saddle patches and a couple of whale indexes available on-line, Mike identified as belonging to the AG Pod. In Puget Sound where researchers are watching killer whales every day, the life history of the three pods, J, K, and L, is quite well known. Up in Alaska the information about individual whales is a bit spottier, but Mike was able to identify one male who was born in 1994 and last photographed in 2010.
There appear to be as many as eight different species of killer whales world wide, three of which have ranges in Alaska. To an untrained eye the different species look identical (which begs the question, how the whales tell each other apart? and how is “species” defined if the different killer whale species probably could interbreed if pressed, but apparently haven’t in tens if not hundreds of thousands of years for what amounts to cultural reasons?). Of the species present in Alaska, one group eats mainly fish (“fish eaters” or “resident” whales) one group eats mainly marine mammals (“mammal eaters” or “transient” whales) and one group hangs out mainly off-shore and eats sharks(off-shore killer whales).
The existence of the off-shore, shark eating killer whales up-ends my mental image of the world. Yes, killer whales are highly social, intelligent, mammals, but sharks are sharks are the nightmare of my childhood (I watched Jaws waaay to young) and finding out that they are eaten by killer whales should make me feel like the killer whales are eating the bogey man, but instead it only serves to make me more scared of killer whales
But I am wandering.
Of the three, fish-eating whales have been the most studied, because the pods in Puget Sound are fish-eaters. The J, K, and L pods each “speak” different dialects, but when the pods are “speaking” to each other they use a fourth common dialect. The dialects are all different enough that researchers in the Puget Sound can leave a hydrophone in the water and get a pretty good idea of who is coming and going and which pods are interacting even when they can’t see the whales themselves.
A fish-eating pod consists of a matriarch and all of her children and grandchildren and great grandchildren, both male and female. Pods break up into smaller groups to feed, so you don’t always see the entire group. Females can live up to 80 years old, and go through menopause (!!!!!!!). Males appear to only live to 40 or so, and the oldest male will often die within a year of the matriarch passing. One theory for this is that males may actually be too big to be very efficient hunters. Males don’t seem to fight each other for mating rights, but the females may find larger males more attractive, and so ungainly large males may be the result of sexual selection. Without the matriarch to help them hunt, large males may not be able to to keep themselves going.
(Related to this, killer whales will catch food for pod members who are heavily pregnant or have newly given birth).
Mammal-eating whales tend to hunt in much smaller groups (the better to sneak up on their prey). There is apparently a killer whale in Glacier Bay, nicknamed T2 by the researcher who has been following him, who eats on average two harbor seals a day.
Mammal-eating whales, in addition to killing gray whales and humpbacks, will also kill sperm whales and apparently even blue whales. In Alaska they will also kill swimming moose (but generally not sea otters, because sea otters lack a blubber layer and are actually 80 lbs of fur, gristle, and spite).
Humpback whales feed in Alaska, but migrate to give birth (the humpback whales we see in Southeast Alaska go to Hawaii, other groups got to Mexico and Japan). One theory for this migration is that they are trying to avoid killer whales when the calves are the most vulnerable.
(Complete speculation on my part: According to Andy Szabo of the Alaska Whale Foundation, the humpback whales who engage in cooperative bubble netting behavior between groups of unrelated individuals do not seem to have greater reproductive success as measured by number of live births relative to other humpback whales, but I don’t think anyone has looked at how many of those calves survive to reproduce themselves. I’m wondering if groups of bubble netting whales continue to associate socially in Hawaii or during migration in a way that might offer defense against killer whales. Someone should look into this…)Killer whales can easily travel over a hundred miles a day.
When we see them, fish eating killer whales are almost always swimming with two or three other whales in very close formation, close enough to touch each other. Often one of them in these small swimming groups will be doing something goofy, swimming on their back, slapping the water with their fluke, or generally lolling about like a little kid walking between adults.
Naturalists try to stay apolitical during their talks, but when you think about a creature who spends much of their life within touching distance of their family, who can easily cover a hundred miles a day, and then you think about putting that animal into a twenty meter tank, alone, it makes your heart hurt. We need ambassadors from the wild, because people don’t protect what they don’t know and love, and between global warming and habitat destruction (never mind continued whaling) they need our protection now more than ever, but maybe we need to allow them to be ambassadors on their own terms, instead of forcing them to do tricks for us. Because all other considerations aside, the stuff they do on their own is way cooler.