Clay+(WK+3)

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Response to "Food-associated vocalizations..." Zanna Clay + Reading through the article I get the impression that the writer was not trying to prove that food calls are functionally referential, but trying to prove that they are not. Many examples were given, and my first question is connected to the number of examples. The authors clearly state that some of the examples, i.e. Gallus gallus (the ancestor of our chicken!), are by all accounts and purposes functionally referential, but as other species are missing some of the assigned markers of that definition, i.e. spider monkeys, somehow the information about another species lack of meeting the definition takes away from the other species functionality. This is summarized in the articles last sentence "Signals during feeding may have the potential to convey a considerable amount of usefull information to receivers, but the evidence for their status as functionally referential signals is, aside from a few cases, less convincing." To me that reads that the evidence for functional reference is not valid unless all species meet the definition set for such. This is further surprising as the authors noted the variance in purpose, or function, of vocalizations associated with food. Listed are reduced predation risk, manipulation of food patch (for this I think a good example would be dolphins basically herding a swarm of fish to greater density), cooperative defense of resources, maintaining association with mates, kin selection, enhancing social status, communication of status, attract allies, and reduce forage competition. With such variety of function, if the species does not NEED any one specifics identifyer to functional reference to get the job done,they will not have it. I do not understand how that takes away from other examples, nor do I understand how if the specific identifyer is not needed, how can it then be an identifyer? If the sparrow does not variate its foodcall because there is no need, then how is it any less specific? It is as specific as it needs to be.... I am not sure if playing back calls through a speaker and observing response of the animal is accurate, I suppose this is to prove that the context is not important, but at the same time supporting non auditory signals are eliminated. if we are looking to find a predessor to speech, or in this case looking to not have a predessor of speech, absence of other signals that are included in the message will qualify or clarify the message. Speech is obviously the most detailed auditory code, and we humans still rely on an enormous amount of non-verbals to clarify messages. I am not sure if the results using auditory only are not tainted for some species. Or certain intonations escape our ears and we play the wrong sound..... The authors are also questioning functional reference based on the animal not varying the call itself based on what food is noted, but vary only the intensity of the call, indicating to the authors that this is a function of the arousal of the caller. I think that leaves out that the arousal of the caller has to be linked to the level of value of the resource. why else would arousal increase, unless value of the resource increases, by whatever the animal values. If that is understood by the receiver, and it fills the function the foodcall has to start out with, then the call does not NEED to be varied, and if it does not need to be done it will not not be done. Such is evolution, stingy on the details unless made to pay. Which reminds me of a remark found in the article on page 6 in the conclusion. "Alarm signals have a critical function in survival, whereas food-associated calls do not." Again, if it was not critically important, it would not happen. Clearly food calls are tightly linked to social structure of the animal. The social norm around food would vary a lot more from species to species, because social bonds, mating, food sources, competitors, size of groups, etc would vary more than the mandate of I am a small social prey animal and I get eaten by things from the sky and from the ground. This is in addition to species that are similar, but seperate breeding groups because they are seperate species :) may come upon different strategies around food (as evolution does not have forsight) but there are not that many strategies that can be alternativly selected for when being attacked by talons from the sky..... I am so impressed with the collection of the facts listed however, though I am not following the conclusion. The vastness of responses and species compared is rich in information. I actually was more skeptical of pre-speech behavior before I read the article that appears to be questioning. Understanding humans as a highly social, highly cooperative species capable of utilizing an unusual range of resources this is making a lot more sense to me know. I can't wait to see what Bickerton says about this. (on a non-scientific note the article reminded me of animals I have met. Page 2 "...for a considerable number of species, calls produced during feeding are also produced in nonfood contexts..." I was thinking of the nickering sound a horse makes when food, a favorite companion, or something else good arrives. Again, the tie to social behavior is so tight that the sound comes to mean both food and company. Also, I was reminded of my first cat, a Siamese, when reading about emotional arousal in connection with variation in food calling. I always told people she had different "words" for some things that I understood (and a few we did not have agreeance on) and there was a clear difference between the regular food call and the one when raw meat was served. So maybe that intense sound reflected her love for beef heart. very much so. But i still understood it. :) )