>> Hello, students. This is Plants and Animals of Southern California and we're sitting underneath a one year old grey whale. Gray whales are really cool. So, I want to tell you a little bit about cetaceans. Cetaceans, is this group of mammals and it includes dolphins and whales and killer whales, the cetaceans, that order of mammals, it diverged from the rest of mammals, maybe fifty five million years ago, you know, a while back. And the current evidence is that it arose out of the artiodactyls. That is the same group that includes antelope and horses and hippopotami. So, it's like the whales came out of the hippopotami. And they start out carnivorous, so the first fossil whales, things in the lineage that's leading up to whales, they have great big teeth and they would go around and eat fish and they had hind legs, too, right? Now, a whale these days doesn't have hind legs, but you can still see, in the embryonic state, you know, when it's a fetus whale, you can still see it's hind legs starting to develop and there's some tiny little bones, the vestigial legs, of the whale. And so, they have a whole lot of things that are just mammal characters, like they're pregnant. And they give rides to babies that have to be born and those babies, when they're born, they have to breathe air right away. I guess the tail comes out first, that's the thinking and then flaps around a little bit. The whole whales, baby whales given birth to and then the mother pushes it up, you know, into the surface and it takes its first breath, right? And whales, whales, they have an umbilical cord, just, you know, just like all the rest of the placental mammals. And so, whales have belly buttons, it's an important fact, whales have belly buttons. And whales, they also, they suckle their young. So, they have titties and they give milk and it's just like very mammalian. The whole thing's very mammalian, right? The milk of whales, it turns out, is like super rich, it's like cream. Okay, so, the early whales, they were toothed whales and they were carnivores and stuff and then time goes on for millions of years and eventually out of those whales, arises the baleen whales. And a gray whale is a baleen whale, where as a killer whale or a dolphin, is a toothed whale. So, there's basically two big groups of whales. There's the baleen whales and they tend to be really big whales and they filter feed their food. So, they're eating things like shrimp, krill and all sorts of stuff like that. So, they have these, like, it looks like a hairbrush or something, on their teeth. And they take in a big gulp of water and then let the water go out through the hairbrush and then bristles of the hairbrush, the baleen, that collects all these little tiny shrimpy things. And they take a lick, yum and they lick their teeth and then they swallow and do the whole thing over again. So, those are the baleen whales. Now, some of the toothed whales also are huge, like, there's a sperm whale that's huge. And it's kind of like the most divergent and most ancient divergent's of the whales, but a lot of the toothed whales are relatively small, like, dolphins or killer whales. Killer whales are a special interesting case. They are pack hunters, like a pack of wolves. And so, you know and they'll take on pretty big stuff. Of course, they can eat a sea lion, but and they'll eat a lot of different other things as well, but they would hunt as a pack. Now, dolphins, dolphins, they have echo location, which is kind of a cool thing. What else has echo location?

>> Bats.

>> Bats, bats, right, have echo location. So, these dolphins, they swim around, make this sound and it bounces off things and so they can kind of hear what it's bouncing off of. And then they can go towards that thing and eat it or they can stay away from it if it's, you know, a rocky shore or something like that. And then the baleen whales, they also make all sorts of great sounds, like, I think they sort of sound like groaning. [groaning sounds] Yeah, yeah. And one of the thing that's kind of interesting about this, is I guess the different individuals of the same species, they can hear this for a long, long ways away, you know, like not just a football field away, but miles and miles and miles away evidently, they can hear these things and they can communicate. And they're all super smart animals. They are pretty social and you know, they have--they're not all equally social, but they--many of them are pretty social. And they can communicate somehow or another. We don't know that much about their communication. Now, the gray whale that's above us, that's the one that you would probably go out, right about now or over winter break and go check out. It migrates, it tends to migrate from up in the Arctic, during summertime, down to Baja, in the winter, where they would then have babies. And then they'll go back up into the Arctic in the summertime. Okay, well, that's all that I have to say about that.