When I'm out in the ocean and I watch a seabird, I think, "Oh, I probably I know what that seabird is doing" - and I don't study seabirds. And the same for the turtles and on and on. But with the whales, a lot of the time, I have no idea what they're doing, and they're the ones I study.

Culture is not usually one of the criterion for personhood, but it has been argued that culture is sort of a medium for a lot of these criteria, such as empathy, and so on.

What I mean by it, and roughly what most biologists who talk about culture mean by it, is either behavior itself, or information that leads to behavior. Information that is picked up through social learning - so, from being with, watching, being taught by others. It's a way that individuals behave or get information about how they will behave that comes directly from the behavior of others.

Studying the behavior of large whales has been likened to astronomy. The observer glimpses his subjects, often at long range; he cannot do experiments, and he must continually try to infer from data that are usually inadequate.

We believe we're seeing, in other animals, a process, or an attribute, that isn't fundamentally different from what we see in humans, so it seems to us to be spurious to call them different things. Now there are aspects of human culture that we don't find in animals, and that's really interesting, but there are also probably aspects of animal cultures that we don't find in humans, and that's really interesting.

Conversation with animals could happen, but I think it would be easier for it to happen with creatures we share a bit more with - those that have been bred to interact with us, like dogs or horses, or ones to whom we have a natural evolutionary link, like chimps and other nonhuman apes. I mean, we do communicate with dolphins and whales, but we're not trying to get to the depths of their understandings. I feel that with animals as different from us as the whales and dolphins, it's likely to work better with us just watching them and trying to figure them out.

Humans are particularly interesting; our culture is incredible, there's no doubt about that. In many respects, no other species matches ours. But in quite a few respects, they do, and that can help us, perhaps, to better understand our own culture. We look at the ways humans are similar to other animals, and at the ways they differ, rather than just saying, "We have culture and you don't."