2009 Week 5 Cooperation
Using examples from your supplements and the chapters (Krebs & Davies 1993) about cooperation, helping and the design of communication signals, ….
Using examples from your supplements and the chapters (Krebs & Davies 1993) about cooperation, helping and the design of communication signals, ….
June 28th, 2009 at 9:57 am
what helps you synthesize ideas across these chapters?
For example, is communication cooperative? If exchange of information is deceitful is it still communication? When selfish eavesdropping occurs, is it more likely to be an adaptation within a species, or part of the predator/prey arms race between species?
June 30th, 2009 at 11:21 am
In chat today we were talking about how fuzzy are some of the concepts of the early ethologists with respect to motivation. Here is a link to some of the papers that cited Gene Morton’s key article on motivational structure. One hot new one in Behavioral Ecology to illustrate where this field of inquiry has progressed!
http://www.journals.uchicago.edu/doi/abs/10.1086/282971
June 30th, 2009 at 11:27 am
Here is a link to the recent article about partitioning “sound space”.
http://beheco.oxfordjournals.org/cgi/content/abstract/arp074v1
In their abstract, they use words like “to reduce”, which comes really close to the folk psychology term “in order to”, which I have been encouraging our folks to put in quotation marks. Lets practice our critical thinking skills. If you were editor of Behavioral Ecology, would you ask the authors to edit their abstract to read “that reduce” rather than “to reduce”? Why or why not?
July 1st, 2009 at 11:25 am
What helps to synthesize ideas throughout the chapters are examples of communication and cooperation.
Communication is discussed throughout chapter 14 of Krebs and Davis regarding communication through signals, displays, receivers, and variable signs. Communication can be cooperative in species, while deceitful to predators in other species.
The discussion of the vervet monkey predator calls, is a good example of how communication is cooperative in groups. The vervet monkey varies its calls by predator. There are three different calls which signal ground, aerial, and tree predators. The group responds appropriately to each call by climbing, jumping out of a tree, and seeking cover. The young vervets learn what calls mean what, and learn consistency with experience. The monkeys are less likely to give calls if there are no group members present, and this suggests that the vervet monkeys intend their calls to be heard by other members (Krebs & Davis 372).
The vervet monkeys were also observed to give deceitful calls of false predators. One example used by Krebs and Davis on page 373 discussed a male vervet monkey using a leopard call to divert an interloping male approaching the group. This call is still cooperative communication even if it is intentional deceit. The interesting observation regarding deceptive calls in vervet monkeys was that the group learned to ignore individual alarm calls. The group learned to ignore calls that were fake, yet still responded to appropriate calls (krebs & Davis 373).
The example of the vervet monkey’s use of variable signals was interesting regarding communication of individual and group behaviors.
July 2nd, 2009 at 8:33 am
Let’s dialogue a bit more about Kate’s interpretation of the alarm calls of vervets as “intentional” and “deceitful”. I read the information on page 373 (Krebs & Davies 1993) a little differently due to the statement on page 372 “specific calls refer to particular predators and elicit an appropriate response but, of course, they do not imply any conscious intention”.
For me, what the authors are trying to communicate is that some behaviors are fixed (reflex-like) responses and others are conditional (learned processing of information influences which response occurs to a given signal). Its easy to miss that point because the example does not refer back to the explicit concept of fixed and conditional as presented in Chapter 7.
However, if we think about it more, this ties back to the foundation of concepts laid down at the beginning of the course. In Units 1 & 2, we were asked to think about the distinction between adaptation by learning, by cultural group transmission, and by evolution (changes in genotype frequency). We said that what is really important is understanding that each of these different types of adaptation relates to a different time scale.
So it seems to me that this would be a good example of how the learned type of adaptation happens on a short time scale of lifetime experience. For example, the male, “Kitui”, called at times that did not reliably predict the presence of a predator. The receivers learned to ignore his calls. It also illustrates the intermediate time frame in which young vervets learn from others in the group (those who learned to respond appropriately to the different types of predators did not get gobbled up). It also illustrates the long term time scale of evolution, because comparing vervets to other monkey species, the vervets appear to have diverged in this learning trait. Or at least we do not yet have evidence that other species like colobus monkeys show this type of socially transmitted adaptation analogous to “words” in humans.
I’d be interested in what others think. Would you critique Krebs & Davies (1993) for writing in a folk psychology “explanatory” mode in the last two chapters, which obscures the basic take-home messages about the concept map that they introduced in the beginning chapters of the book? If you were editor of this book, or planning to write an updated version, would you recommend more explicit statements about how examples illustrate the basic concept map?
For that matter, what is the basic concept map that you have learned to apply to organize the diverse information in this course?
July 2nd, 2009 at 9:19 am
I’m feeling reflective this morning….thinking about what folks said in chat yesterday about how the “big picture take home messages” about behavioral ecology are still fuzzy, then reading the quiz answers today. What jumps out at me is something that I take for granted, and yet I realize may not be immediately obvious to other folks in our collaborative learning group.
That has to do with how our brains synthesize information, which of course is our objective for doing these blogs. I remember when I used to puzzle about this as a student and asked Konrad Lorenz. He pointed to my watch. He said “your watch is running right now as a whole. To really understand how it is running and why it was designed that way, we would need to take it apart piece by piece. We could have all those pieces spread out on the table and would still not understand how it works until we put all those pieces back together again into the whole and watch it run smoothly. ”
The watch analogy was Konrad’s way of explaining the nature of science. He was openly critical of scientists who focused more on reductionism “taking the watch apart”, and warned me not to become like my American colleagues. Naturally, that was a little upsetting to me, since I am American. However, I understood at a gut level what he was talking about. In Austria, he had literally led us “goose girls” to the pond to watch our geese for long hours in semi-natural conditions so that we would understand how all these pieces fit together as a whole. And the experience of careful observation of all the natural history of the geese did leave a mark on me. I am restless with each of the tests of hypotheses until I see how the resulting knowledge fits together, synthesized into a bigger picture, until the “watch has been put together”.
My sense of reading Krebs & Davies (1993) is that they are happier looking at all the pieces of the watch spread out on the table. They obviously have a mental map of all the concepts in their heads when they write. It’s like they were there when the watch was taken apart, so they don’t need an instruction manual as to how to put it back together.
Years after Konrad’s analogy of the watchmaker, I was reading a book about teaching science. One image still sticks in my mind. It was the head of one student with facts randomly stuffed into it. Next to it was the drawing of another student with a mental map, sort of like a filing cabinet, or I guess today we would use the analogy of a set of folders like on our computer desktops. The caption was “a mental map helps students better retrieve information, yet they have to explicitly learn to build that map in their minds by identifying concepts and the relations between concepts”.
Enough ramblings for now. I guess I was just hoping these words would spark some dialogue that would help make that concept map in behavioral ecology more explicit for each of you.
July 2nd, 2009 at 3:40 pm
This week brought to light the concept of communication among species for me, as in the Gene Morton study of song birds in Panama. This study showed that species that lived below the canopy had lower frequencies. These same birds showed a narrower range of frequencies than their counterpart of the grasslands of Panama. Morton et al (1991) “The birds in more open habitats have songs with higher maximum frequency, more rapidly repeated notes, and wider range of frequencies than those of forest birds.” Krebs et al (1991) This point seems to make sense, but I have not really ever stopped to think about it. I would like to conclude this last blog by saying that I thoroughly enjoyed this course; it has opened my eyes to the way “things” work and why. I love the examples that were used to help connect objectives together.
Krebs JR, Davies NB. 1991 An Introduction to Behavioral Ecology. 353
Morton, E.S. 1975 Ecological sources of selection on avian sounds. Amer. Natur 109, 17-34
July 3rd, 2009 at 5:24 am
This last weeks material on cooperation and helping is what i found to be the most interesting. The debate of whether a helper is genetically predisposition to become a helper or is helping a result of ecological constraints. In the Florida scrub jay example even though setting out to find a mate and breeding would benefit a male better, the helper is usually a male and usually a previous offspring. This male helper seems to incur a large amount of cost associated with being a helpers by feeding and defend the new brood of the adult breeding pair. The breeder seem to be benefited by the presence of the helper which could help in spotting predators and give warning calls to chicks (Krebs and Davis 1993) and they help with feeding chicks. Even though a helper is helping the adults feed the nestlings it does not really seem to be an increase in chick survival because they are really not getting extra food. This help from the helper may be helping the breeding pair to have more time to rest, preen and to take care of themselves so that the breeding pair has a better survival rate to be able to continue to reproduce in the future.
Another possibility as to why some helpers may stay at home is that suitable habitat may be limited or sparsely scatter. Females in this example do not defend territories but move on to try to find breeding vacancies while young males if they live right away try to find vacant territory which is extremely limited. So if these young males stay at home to help it may be possible that their helping behavior pay off in the future by the young male inheriting part or all of his fathers/natal territory and breeding space.
It is difficult to resolve with the scrub jay example if the jays are directly benefiting in fitness or is it an indirect fitness benefit gain. But it seems to be a case where both indirect and direct fitness gains play a role as to why these males stay as helpers and both cost and benefits and casual and functional questions have to be asked together in order to continue testing hypotheses about species with helpers.
July 3rd, 2009 at 7:24 am
Trent and Heather, thanks for some great examples that help illustrate how the pieces fit together in a whole.
Also, thanks to Walter for bringing to my attention the fascinating work by Winnie Eckard and Klaus Zuberbuhler, who have evidence that more monkey species produce distinct calls for raptor and leopard predators. I’d be interested in hearing more here on blog!
July 3rd, 2009 at 7:59 am
I’m really excited by a new article on the evolution of calling behavior in deer. It combines molecular and behavioral data in developing hypotheses about the evolutionary history of deer. One of the surprises is that our white-tail deer are more closely related to reindeer than to fallow deer!
Male vocal behavior and phylogeny in deer
Henri Cap, Pierre Deleporte, Jean Joachim and David Reby. 2008
This article cited a fascinating study on signal design, which Janell brought to my attention:
Feighny, J.A., Williamson, K.E. & Clarke, J.A. 2006. North American Elk bugle vocalizations: male and female bugle call structure and context. J. Mammal. 87, 1072-77
July 3rd, 2009 at 3:34 pm
The examples in the chapters combined with the essays and personal application to the text is what has helped me synthesize across the chapters. During week three, my essay was based on the sequential assessment of bull elk during a contest of strength. The elk bugle is the first part of the assessment. Through studying my supplemental information I read the importance of the frequency to travel in open areas. (Red deer, on the other hand have the lower frequencies because they have adapted to thick vegetation habitats.) There was a correlation to the study that Trent mentioned earlier conducted by Gene Morton on the song birds in chapter 14. The frequency of birds that lived in higher density vegetation habitats had lower frequencies. This is an example of how all aspects are important when understanding behavior, and as Dr. Packard mentioned earlier, I believe this is what Konrad Lorenz meant by evaluating all the pieces of the watch.
July 3rd, 2009 at 7:49 pm
After tying-in my supplemental material on elk bugle call structure and context, there were several similarities with the excerpts from Krebs and Davies on mangabey monkeys. Both elk and monkeys use different signal structures to communicate within the group/herd and between groups/herds over long distances, and like the songbirds described by Morton, elk communicate at different frequencies and tones depending on their environment. These communication strategies are typical of signal patterns described by Krebs and Davies and show that animal signals have evolved to communicate intentions between and within groups, at the correct frequency and tone, and transmitted successfully over their home ranges, taking into consideration topography and vegetation. The chapter on communication also has ties to all the other chapters since signaling is critical in cooperation, breeding/mating, fighting, foraging, and group dynamics. Finally, this course has introduced me to a subject that has always fascinated me, but I had never had the opportunity to learn about before!
July 3rd, 2009 at 8:46 pm
One method to practice synthesizing information across chapters is to review the behavior of a particular species as we have here in class. I noticed that that many of the supplements I chose only addressed a small portion of the concepts associated with a behavior. My supplement on cooperation, for example, gave a report of the observations of cooperative group prey herding and had a very limited discussion of the costs and benefits (Benoit-Bird & Au 2009).
To a professional who does not understand the concepts of behavioral ecology, selfish genes, optimality, causation and function, the article may have appeared all encompassing. To understand the cooperative spinner dolphin behavior to the level presented in our text, one would have ask if the dolphins were kin, if they received an improved fitness benefit from the behavior, and what other behavioral characteristics or traits correlated with the cooperative group hunting behavior. Then is becomes apparent that in order to develop a testable hypothesis about that one behavior, cooperation, multiple behavioral concepts from throughout our text book would need to be addressed. In just one species, there exists a complex interaction of multiple behaviors where one behavioral characteristic can impact many others. Many sections of our text such as economic decisions, predator verses prey, competing for resources, living in groups, sexual conflict, mating systems, cooperation and helping and the design of signals could all be relevant topics in the critical analysis of cooperative prey herding in the spinner dolphins (Krebs & Davies 1993). The most complete understanding of the natural selection forces comes from synthesizing all of the perspectives of behavioral relationships and viewing both the causal and functional factors. Therefore we must critically review the conclusions presented by many studies, which for practical reasons have resource and time constraints that limit the breadth of their analysis.
I also discovered an interesting article on the practical applications of combining behavioral ecology with conservation efforts (Sutherland 1998). The author provides some real world examples of how to integrate the two disciplines and advocates the comparative method for studying species which are closely related to a rare or endangered species of concern (Sutherland 1998).
Benoit-Bird, K.J., and Au, W.W.L. 2009. Cooperative prey herding by the pelagic dolphin,
Stenella longirostris. Journal of the Acoustical Society of America 25:125-137.
Sutherland, W.J. 1998. The importance of behavioral studies in conservation biology. Animal Behaviour. 56:801-809.
July 3rd, 2009 at 9:15 pm
I’d like to go ahead and toss my two cents in because this really has been an interesting course for me and I have been introduced to many new concepts and mechanisms. For me, the best overall synthesizer was the analogy of an arms race and how it fit in literally throughout the course. The unit on predator vs. prey cited very clear studies and offered not only examples of adaptions by predator and prey, but also explored questions about why conspicuous coloration would be selected for as opposed to cryptic or whether or not an evolutionary equilibrium has been reached or is the arms race still ongoing (Krebs and Davies, 1993)? I found these questions to be quite profound. In keeping with the watch analogy, while I would tend to agree with Dr. Packard that the authors generally seem more concerned with laying out the parts at the expense of the whole, these and other questions were examples in my mind of where they zoomed out and captured a broader picture.
So to relate the arms race analogy to this week’s readings, I was struck by the example of the Tungara frogs and swordtails. Theirs is an arms race to attract a mate, which will in turn increase their genotypic frequency in the population (is there a better “weapon” that this in an evolutionary arms race?). The advantage, then, is given to the individual who is able to pick up on the preferred signals of the female actors and react according to their bias. The authors (Krebs and Davies, 1993) even cite one possible reason why an individual may not respond to a potential mate’s bias as “evolutionary lag”, which implicitly states that a race is underway.
And finally, to tie that in with the supplemental material I used for this week’s essay, there is an observed arms race underway in an African rainforest where prey living in mixed-species associations are using signaling to defend against predation. One study (Wolters and Zuberbuhler, 2003) focused on Diana and Campbell’s monkeys and how both species had predator specific alarms. Even more amazing than this is that both species understand each others specific alarm calls and will react accordingly! In addition to the obvious benefit of increased vigilance and alarms that transcend interspecies boundaries, both species were able to capitalize on areas of the canopy that are unavailable to them (due to predation pressure) when they are separated. Secondly, the Campbell’s monkeys, which are more cryptic in their colorings and vocalizations, were found to be much more conspicuous in their mixed species association, while the Diana monkeys, who are more vocal and conspicuously colored, were able to spend more time foraging. A second study (Eckardt and Zuberbuhler, 2004) also focused on mixed-species associations between two primate species in the same region of rainforest and their signaling. Again, both species of monkeys (Diana and putty-nosed) were able to recognize each others predator specific alarm calls. The main difference in this study was that these two species occupy very similar ecological niches (unlike the Diana and Campbell’s monkey who are found in different levels of the canopy when not associated) when not in their mixed-species associations. This made the presence of an ecological constraint (food availability) much more important in this observation. It was shown that when fruit, which is the preferred food of both species, was readily available the association worked to the mutual benefit of both species. However, for the two months out of the year when fruit is not in season, the Diana monkeys were observed behaving aggressively towards the putty-nosed monkeys even when foraging or feeding wasn’t occurring. Despite this observation, the mixed-species association between the two picked up again once the fruit became available, so the benefits derived from a reduction in predation pressure seem to outweigh the cost of resource competition. The results of both studies seem to suggest that groups, regardless of which species they belong to, involved in a mixed-species association derive more benefits that if they were on their own, and this would give them an advantage in the “genotypic arms race” occurring in their population.
Krebs, J.R. & Davies, N.B. 1993. An Introduction to Behavioral Ecology. Blackwell Publishing, Massachusetts.
Eckardt, Winnie and Zuberbuhler, Klaus. 2004. Cooperation and competition in two forest monkeys. Behavioral Ecology. 15, 400-411.
Wolters, Sonja and Zuberbuhler, Klaus. 2003. Mixed-species associations of Diana and Campbell’s monkeys: the costs and benefits of a forest phenomenon. Behaviour. 140, 371-385.