A New Species of Killer Whale?

Research is being done world-wide on killer whales and scientists are collaborating on data about DNA studies, feeding preferences, migratory paths, and behavioral differences. This week's science lecture concentrated on what was being done specifically down here to prove that there is a different species of killer whale that exists in Antarctica. Currently, there is only one species recognized, Orcinus orca, and researchers here are proposing that another species could be identified once enough data is collected. Some of the data that suggests it is a different species is that it is one to one and a half meters shorter (they call it the "dwarf species") and that it has very different feeding behaviors and strategies than other killer whales.

From their studies, scientists have split all populations of orcas into three ecotypes. From Websters dictionary, "an ecotype is made up of subspecies or varieties adapted to a particular set of environmental conditions". Ecotypes can be established by studying morphology, feeding preferences, migratory paths, and the overall environment of a set of organisms. An ecotype is not considered a different species, but once enough differences have been established between one ecotype and another, it can lead to a new species being named. One of the most important pieces of data they have is that the three ecotypes do not interbreed, even though they coexist in many places. Reproductive isolation is sometimes enough evidence to elevate an ecotype to being recognized as a separate species.

One ecotype of orcas hunts in large packs, eats only fish, is very vocal and is black/grey and white. Another group hunts in smaller groups, eats mammals, is not as vocal, is very dark black and white, and is the largest kind(this is the typical whale found at Sea World). The last group is the one described down here as the "dwarf species". It is black/grey and white, they think it eats fish mostly, and it spends most of its time in pack ice. It has a distinctive behavior of "spy hopping" (see picture below) to see the ice patch openings and possible prey.


The killer whales in this picture are spy hopping. It was reported that about 50 of them were seen off shore in the channel the ice breaker made just last week. The whales follow the icebreaker in every year. I didn't take these pictures (I got it from someone who was here a few years back). The whales haven't come close enough in the channel for us to see yet. Can you see the whale popping up behind the ship?


As for genetic studies, the scientist showed us the most amazing pictures of how he collected tissue samples. The pictures showed him standing on the ice edge by the channel and shooting a dart with a rubber snout on the end. The dart has a small sharp piece underneath that tears off a tiny piece of flesh and then bounces off the whale and onto the ice. These DNA studies will be the final piece of evidence they need to prove it is a separate species. They also shoot darts that attach satellite receivers to their dorsal fins and this is how they track them to find out where they spend most of their time.

Now, I get to end this post with a grisly story. One time a photographer was with the group and as he was peering over the ice edge, a killer whale shot up out of the water and knocked him down. The photographer was trying to protect his camera from the salt water the whale splashed and wasn't thinking he was in danger, even though the whale was laying side by side with him on the ice now. Then to his horror, it rolled over on him and pinned him down underneath its body. The presenter said that they just looked at each other for a little while, then the whale rolled back over and slid back into the water. Crazy, eh?