Assumptions and altruism

I recently read "Among Whales" by Roger Payne. For those who haven't read it, it's his account of living in Argentina and working with right whales, and some of his ideas on science and whales that he hasn't actually done the research to back up, etc. He mentions that if his ideas provoke someone into trying to disprove them, he'd be glad. Well. Consider me provoked.

One of his ideas is that fin whales produce 20 Hz sounds in order to advertise food patches to the rest of the "herd" in the Southern Ocean. Over a whale's lifetime, it will be both the advertiser and the recipient, and the process will continue by reciprocal altruism as all whales benefit and contribute by turns. Sounds all nice and cuddly, doesn't it? But when I read that portion (multiple times, mind you, just to be sure I wasn't missing some key part that would make the whole idea make sense) all that struck me was that he was assuming that no one was cheating (listening without advertising in return), and that no other species were involved. Maybe my background in game theory and ecological modeling shaped my opinions, but why should fin whales advertise patches of krill to other species (blue whales, humpbacks, etc) that very probably can hear and interpret the 20 Hz calls? It made no sense to me, so I started looking for published studies.

One paper from Nature found that only male fin whales in a certain area were producing sounds (9 of 21 males calling; 0 of 22 females calling). Reciprocal altruism under those conditions would not work; all females are thus "cheaters". And what about the non-calling males? Were they not in a food patch at the time, or were they just not advertising that they had found food? The authors of the paper postulate that the calling males are advertising food patches to females in order to secure mating opportunities based on the following facts: 1) only males called; 2) the study area was used for feeding; 3) the calls are acoustically optimal for long distance signalling; and 4) fin whales do not aggregate in specific areas for breeding.

I am willing to be convinced that male fin whales may "mate gift" food patches to females before mating, but the reasoning in the Nature paper seems very weak. I'm reminded of a study breeding amphibians, in which certain males produced calls to attract females, while "satellite" males lurked near the callers and waited for females to approach. When they did, the satellite would attempt to "steal" a mating opportunity from the caller. Isn't it possible that fin whales follow the same strategy? A silent male locates a caller and lurks nearby until the female approaches for food. Then, he either attempts to mate, or begins to call only when he knows a female is nearby. Or, he simply eats the food himself and benefits in that way.

The evidence that I would need to be convinced of "mate gifting" is 1) a long term, individual based study on which males call when; and whether or not they are consistently next to food when they call, 2) a study of paternity in which calling males have increased breeding success as opposed to silent males, and 3) a study indicating that females are indeed attracted to 20 Hz calls during the breeding season. (I am under the impression that the calls are highly seasonal, which is appropriate to a mating display. If they are not seasonal, and still males are the only callers, I would still want evidence from studies 1 & 2 above.)

Reciprocal altruism is difficult to prove at the best of times, and systems of large, long-lived, fast-moving, and geographically widespread animals are NOT ideal for altruism studies. I admit that it may be found in some cetacean species; however, it requires a huge burden of proof, and this system currently does not have that.