Rendell and Whitehead state that marine ecosystems are more variable than terrestrial ecosystems over time scales of months or longer. The marine environment is actually less variable than the terrestrial at these shorter time scales, and probably equally variable over centuries. This issue is important when considering claims that environmental variability affects benefits of social learning versus individual learning and genetics.

The most important clarification we bring in our reply to commentators concerns the problem of the “explanatory gap”: that is, the gulf that separates physical processes in the brain from the experienced quality of sensations. By adding two concepts (bodiliness and grabbiness) that were not stressed in the target article, we strengthen our claim and clarify why we think we have solved the explanatory gap problem, – not by dismissing qualia, but, on the contrary, by explaining why sensations have a “feel” and why “feels” feel the way they do. We additionally clarify our views on: internal representations (we claim internal representations cannot explain why sensation has a feel), on behaviorism (we are not behaviorists), on perception and action (we believe there can be perception without action), and on the brain (we believe the brain does do something important in perception).

While supporting the claim for culture in cetaceans, I suggest that Rendell and Whitehead's argument is potentially incomplete if based solely on ethnographic evidence. The notion of cetacean culture can also be explored experimentally. I hope to complement the authors' assertion by discussing dolphin brain and behavioural research findings, thus contributing to a more holistic argument for culture in dolphins.

Rendell and Whitehead adopt a weak definition of culture to allow low standards of evidence for marine mammals, but they do not adequately rule out genetic factors or individual versus social learning. They then use these low standards to argue that some whales have unique cultures only matched by humans. It would have been more helpful to specify data gaps and suggest critical tests.

Recent evidence suggests imitation is more developed in some cetaceans than the authors imply. Apart from apes, only dolphins have so far shown a grasp of what it is to imitate; moreover dolphins ape humans more clearly than do apes. Why have such abilities not been associated with the kind of progressive cultural complexity characteristic of humans?

Although the majority of commentators implicitly or explicitly accept that field data allow us to ascribe culture to whales, dolphins, and other nonhumans, there is no consensus. While we define culture as information or behaviour shared by a population or subpopulation which is acquired from conspecifics through some form of social learning, some commentators suggest restricting this by requiring imitation/teaching, human analogy, adaptiveness, stability across generations, progressive evolution (ratchetting), or specific functions. Such restrictions fall down because they either preclude the attribution of culture to nonhumans using currently available methods, or exclude parts of human culture. The evidence for cetacean culture is strong in some cases, but weak in others. The commentaries provide important information on the social learning abilities of bottlenose dolphins and some interesting speculation about the evolution of cetacean cultures and differences between the cultures of different taxa. We maintain that some attributes of cetacean culture are currently unknown outside humans. While experimental studies, both in the laboratory and in the wild, have an important role in the study of culture in whales and dolphins (for instance in determining whether dolphins have a Theory-of-Mind), the real treasures will be uncovered by long-term observational studies at sea using new approaches and technologies.