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Behavioural ecology: Ecological consequences of adaptive behaviour
TREE vol. 1, no. 2, August
1986
0 occurs at three sites, this gives us six comparisons of performance of resident versus alien diet (resident at I, versus alien at II and Ill, resident at II, versus alien at I and Ill, etc.). In eight of nine North American, 18 of 19 Kalaharan, and 31 of 49 Australian species, the resident diets gave a better performance, on average, than the alien diets. In only one species (in North America) did the resident do worse than the aliens (all the rest were ties). Simply, every species appears to adjust its diet at each site to reduce the total competition from the other species present. Pianka’s book has some simple yet important messages. Some of what he finds conforms to existing theory of competition and niches. But particularly when we look at issues at a larger organisational scale, the differences in his communities are not
easy to explain. We are unlikely to develop ideas about the large scale features of communities in a vacuum, yet studies of large numbers of species are rare. The breadth of Pianka’s study - as well as its detail - makes it a unique contribution.
Behavioural Ecology:Ecological Consequences The book’s 34 papers are allocated of AdaptiveBehaviour among five sections. The first, entitled ‘Selective Review’, lacks a comedited by R. M. Sib/y and R. H. Smith, mon behavioural theme, although Blackwell, 7985. f48 hbk, f 19.50 pbk three of the seven papers consider (ix + 620 pages) ISBN 0 632 01359 I li:a history theory. The second through fifth sections are more Relying on economic models focused. The respective sections inspired by principles of natural discuss foraging, spacing behaviour, selection, behavioural ecology has breeding behaviour, and social enjoyed considerable success in organization as plausible foundapredicting certain aspects of the tions for predicting or interpreting behaviour of individual animals’. population dynamics. Some of the Given a reasonable (though incompapers report original results. Severplete) understanding of individual al contributors offer highly selective, behaviour, we can ask if that but informative, reviews of their preknowledge suggests predictions vious papers. about significant attributes of single The book is not intended as a surpopulations or communities of covey of contemporary behavioural occurring species*. In 1984 the Britecology, despite the collective ish Ecological Society met to explore breadth of the five sections. The the implications of adaptive bemore specific aim is to expand the haviour for the dynamics, regulation, scope of behavioural ecology toward and stability of populations. The an effective interaction with theories resulting volume no doubt will of population growth and regulation. ecologists’ interest in advance Neither the difficulty nor the potenexamining behavioural strategies as tial significance of this objective mechanistic bases for populationshould be understated. A few of the level phenomena. papers discuss interesting topics, but forge only weak links between behavioural and population ecology. There is little new in the general statement that behavioural variation among individuals can induce variation in survival or fecundity, which in turn influences a population’s expected growth rate. However, a number of the papers achieve a successful and perceptive integration of the economics of behaviour and population dynamics. I liked Parker’s contribution; using game theory, he calculates expected fitnesses for
individuals engaged iir’a predatorprey arms race. The game lacks an evolutionary stable solution by design. Given coupled equations for predator and prey densities, Parker demonstrates numerically that cycles in the frequencies of the behavioural strategies can drive cycles in the population sizes of both predator and prey. Perhaps a more important lesson is that quantitative hypotheses about population dynamics may be generated rigorously by allowing the parameters of growth equations to depend on a model of adaptive behaviour. Only five papers in the book discuss interactions involving two or more species. As Schoene? points out, one can propose possible behavioural bases for a community’s properties in two different ways. Behaviour may be incorporated into population dynamics, as suggested in the volume under review. Secondly, behaviours such as dietary choice4 and habitat utilization5 of different species can be compared to an expectation under interspecific independence, or studied in an experimental manipulation of densities. In other words, a knowledge of behaviour may help us understand a lot more than demography. The book’s intended focus on poputation dynamics probably discourages discussion of community ecology. Ecologists with an interest in behavioural mechanisms underlying natural communities should consult the symposium edited by Price’, as well as the volume bv Sibiv and Smith.
A second similarity involves the extent to which the species shift their diets from site to site. We might expect the total competition suffered by a species Q to be related to the sum of the products between overlap in diet with each of the other species A,B,C, . . . . and the corresponding density, X*,X,, Xc, Calculating this sum for species 0, at each site it occurs (I, II, ...I gives a measure of species o’s performance as a ‘resident’ (the smaller the sum, the better the performance). We can now ask how species 0 would manage at a particular site (say, site I) if it adopted the diet it chooses at the other sites at which it occurs. To obtain measures of this ‘alien’ performance, we calculate the summed overlapdensity products for species A&C, . . . . at site I, using species Q’s diet first at site II, then Ill, and so on. If species
Stuart L. Pimm Dept. of Zoology and Graduate Program in Ecology, The University of Tennessee, Knoxville, TN 379% USA.
References 1 Cody, M.L., and Diamond, J.M. (1975) Ecology and Evolution of Communities,
Belknap Press 2 Diamond, J.M., and Case,T.J. (1986) Community Ecology, Harper and Row 3 Strong, D.R., Simerloff, D., Abele, L.G., and Thistle, A.B. (1984) Ecological Communities: Conceptual issues and the Evidence, Princeton University Press
Behavioural Ecology
52
TREE vol. 7, no. 2, August
1986
A primary purpose of this review is to assess the volume in light of current or possible future trends in ecology. Paradigms for the study of populations and communities are diversifying ‘e8. It seems reasonable to me that the models, methods, and results of behavioural ecology will prove useful in formulating testable hypotheses about population regulation and community ecology. The
volume edited by Sibly and Smith takes an important step in that direction.
Thomas Caraco
Department of Biological Sciences, StateUniversityof New York, Albany, New York 12222, USA. rieferances 1 Krebs, JR, and Davies, N.B. (1984) Behavioural Ecology: An Evolutionary Approach (2nd edn), Blackwell 2 Pulliam, H.R. (1976) in Perspectivesin
Ethology (Klopfer, P.H., and Bateson, P.G., eds), pp. 31 l-332, Plenum 3 Schoener, T.W. (1986) Am. Zoo/., 26, 81-106 4 Pulliam, H.R. (1986) Am. Zoo/., 26,71-80 5 Moermond, T.C. (1986) Am. Zoo/., 26, 23-38 6 Price, M.V. (1986) Am. Zoo/., 26,3-4 7 Roughgarden, J. (1983) Am. Nat., 122, 583-601 8 Strong, D.R., Jr (1983) Am. Nat., 122. 636-660
MonographingNatural
HoneybeeEcology by Thomas D. Seeley, Princeton University Press, 7986. f28.40 hbk Ix + 207 pages) ISBN 0 69 108397 6 Ecology is a hungry discipline, consuming others at a fast rate. Originally physiological in nature, it now covers almost everything concerned with whole-organism it has been defined as biology; ‘scientific natural history’. Honeybee Ecology is a wellwritten summary of the ecology of the genus Apis, and concentrates for obvious reasons upon A. mellifera. In keeping with that laudable recent tendency among academic field biologists of openly admitting in print our enjoyment of natural history and love of our study animals, Thomas Seeley communicates his enthusiasm for honeybees in a very effective and natural manner. ‘The honeybee is a wonderful example of adaptation’ is his opening line, and he follows it with numerous engaging extravagances: the honeybee is an ‘extremist’, we learn, and in its communidation ‘is unsurpassed among animal communication systems in its capacity for coding precise yet flexible messages’ (note animal not insect). This is as it should be; any ecologist without such a crush on his/her organism is a Scrooge indeed. Seeley’s aim is to redress the im-
balance he sees between the multitudinous studies of how honeybee societies work from a physiological and mechanistic standpoint, and the few investigations that consider how natural selection has shaped their social system. In doing this, he takes us through chapters on the evolutionary origin of the genus and its domestication, the structure of the colony, its annual cycle, reproduction, nest-site selection and nest construction, the collection of food, temperature control and colony defence, concluding with a comparison between the various races and species of the genus. The text is strongest, naturally, in areas where Seeley himself has carried out much of the work to which he alludes. I like particularly the parts that deal with honeybee natural history, society structure and the annual cycle, colony foraging, defence, and thermoregulation. Surprisingly, the chapter comparing different races and species works less well. In the case of the interspecific comparisons, I suspect it is partly because of the odd perspective of trying to explain why they are different sizes. Apis dorsata has a body mass of about 155 mg, whereas A. florea is only 32 mg. Such questions are of course at the heart of ecological explanations, but I feel that not much is gained by their use here. For example, the discussion of equilibria1 body temperature is inadequate, nowhere are there any data, and it adds nothing to the story. Simplistic formulations also appear in the section on feeding, where the theory of central-place foraging is used to illustrate the assessment of patches. I find the argument here very unconvincing, and some obvious points are missing. For example, Seeley regards as ‘unclear’ why the maximum volume of nectar in the crop is unrelated to
sugar concentration (a point that is well-documented in the uncited superb work’ of Andreas Bertsch on bumblebees), but increases as patch time decreases and travel time increases. The latter must be related to the cost of flying with a laden crop: recent work (with honeybees) has shown that crops are not always filled to capacity. I have chosen to illustrate these examples not to pick holes in what is said, but to show that Seeley may not have achieved his aim. He is trying to bring evolutionary ideas to honeybee ecology: in the attempt, I think he warps slightly the good work he does in the bulk of the text. While we have all heard too much about the ‘Panglossian paradigm’ of the adaptationist programme, it is relevant here. Trying to fit optimality models to everything results in some misfits, for instance in Seeley’s sections on life-history traits and the discussion of the costs and benefits of defence. This is a good book, and very enjoyable to read. Much of it is really the ‘scientific natural history’ of honeybees, which sometimes fits badly onto the Procrustean bed of insistent evolutionary thinking. Many valuable insights into behaviour and ecology have of course been adduced from our current genetical understanding of bees, and Seeley describes these very well and makes much of them. As someone once said to me, perhaps one day academic ecologists will once again feel proud to write books entitled ‘The natural history of. .‘. Francis S. Gilbert Department ofZoology.Nottingham University, Nottingham NG7 2RD. UK Reference 1 Bertach, 325336
A. (1984)
Oecologia, 62,
1986
0 occurs at three sites, this gives us six comparisons of performance of resident versus alien diet (resident at I, versus alien at II and Ill, resident at II, versus alien at I and Ill, etc.). In eight of nine North American, 18 of 19 Kalaharan, and 31 of 49 Australian species, the resident diets gave a better performance, on average, than the alien diets. In only one species (in North America) did the resident do worse than the aliens (all the rest were ties). Simply, every species appears to adjust its diet at each site to reduce the total competition from the other species present. Pianka’s book has some simple yet important messages. Some of what he finds conforms to existing theory of competition and niches. But particularly when we look at issues at a larger organisational scale, the differences in his communities are not
easy to explain. We are unlikely to develop ideas about the large scale features of communities in a vacuum, yet studies of large numbers of species are rare. The breadth of Pianka’s study - as well as its detail - makes it a unique contribution.
Behavioural Ecology:Ecological Consequences The book’s 34 papers are allocated of AdaptiveBehaviour among five sections. The first, entitled ‘Selective Review’, lacks a comedited by R. M. Sib/y and R. H. Smith, mon behavioural theme, although Blackwell, 7985. f48 hbk, f 19.50 pbk three of the seven papers consider (ix + 620 pages) ISBN 0 632 01359 I li:a history theory. The second through fifth sections are more Relying on economic models focused. The respective sections inspired by principles of natural discuss foraging, spacing behaviour, selection, behavioural ecology has breeding behaviour, and social enjoyed considerable success in organization as plausible foundapredicting certain aspects of the tions for predicting or interpreting behaviour of individual animals’. population dynamics. Some of the Given a reasonable (though incompapers report original results. Severplete) understanding of individual al contributors offer highly selective, behaviour, we can ask if that but informative, reviews of their preknowledge suggests predictions vious papers. about significant attributes of single The book is not intended as a surpopulations or communities of covey of contemporary behavioural occurring species*. In 1984 the Britecology, despite the collective ish Ecological Society met to explore breadth of the five sections. The the implications of adaptive bemore specific aim is to expand the haviour for the dynamics, regulation, scope of behavioural ecology toward and stability of populations. The an effective interaction with theories resulting volume no doubt will of population growth and regulation. ecologists’ interest in advance Neither the difficulty nor the potenexamining behavioural strategies as tial significance of this objective mechanistic bases for populationshould be understated. A few of the level phenomena. papers discuss interesting topics, but forge only weak links between behavioural and population ecology. There is little new in the general statement that behavioural variation among individuals can induce variation in survival or fecundity, which in turn influences a population’s expected growth rate. However, a number of the papers achieve a successful and perceptive integration of the economics of behaviour and population dynamics. I liked Parker’s contribution; using game theory, he calculates expected fitnesses for
individuals engaged iir’a predatorprey arms race. The game lacks an evolutionary stable solution by design. Given coupled equations for predator and prey densities, Parker demonstrates numerically that cycles in the frequencies of the behavioural strategies can drive cycles in the population sizes of both predator and prey. Perhaps a more important lesson is that quantitative hypotheses about population dynamics may be generated rigorously by allowing the parameters of growth equations to depend on a model of adaptive behaviour. Only five papers in the book discuss interactions involving two or more species. As Schoene? points out, one can propose possible behavioural bases for a community’s properties in two different ways. Behaviour may be incorporated into population dynamics, as suggested in the volume under review. Secondly, behaviours such as dietary choice4 and habitat utilization5 of different species can be compared to an expectation under interspecific independence, or studied in an experimental manipulation of densities. In other words, a knowledge of behaviour may help us understand a lot more than demography. The book’s intended focus on poputation dynamics probably discourages discussion of community ecology. Ecologists with an interest in behavioural mechanisms underlying natural communities should consult the symposium edited by Price’, as well as the volume bv Sibiv and Smith.
A second similarity involves the extent to which the species shift their diets from site to site. We might expect the total competition suffered by a species Q to be related to the sum of the products between overlap in diet with each of the other species A,B,C, . . . . and the corresponding density, X*,X,, Xc, Calculating this sum for species 0, at each site it occurs (I, II, ...I gives a measure of species o’s performance as a ‘resident’ (the smaller the sum, the better the performance). We can now ask how species 0 would manage at a particular site (say, site I) if it adopted the diet it chooses at the other sites at which it occurs. To obtain measures of this ‘alien’ performance, we calculate the summed overlapdensity products for species A&C, . . . . at site I, using species Q’s diet first at site II, then Ill, and so on. If species
Stuart L. Pimm Dept. of Zoology and Graduate Program in Ecology, The University of Tennessee, Knoxville, TN 379% USA.
References 1 Cody, M.L., and Diamond, J.M. (1975) Ecology and Evolution of Communities,
Belknap Press 2 Diamond, J.M., and Case,T.J. (1986) Community Ecology, Harper and Row 3 Strong, D.R., Simerloff, D., Abele, L.G., and Thistle, A.B. (1984) Ecological Communities: Conceptual issues and the Evidence, Princeton University Press
Behavioural Ecology
52
TREE vol. 7, no. 2, August
1986
A primary purpose of this review is to assess the volume in light of current or possible future trends in ecology. Paradigms for the study of populations and communities are diversifying ‘e8. It seems reasonable to me that the models, methods, and results of behavioural ecology will prove useful in formulating testable hypotheses about population regulation and community ecology. The
volume edited by Sibly and Smith takes an important step in that direction.
Thomas Caraco
Department of Biological Sciences, StateUniversityof New York, Albany, New York 12222, USA. rieferances 1 Krebs, JR, and Davies, N.B. (1984) Behavioural Ecology: An Evolutionary Approach (2nd edn), Blackwell 2 Pulliam, H.R. (1976) in Perspectivesin
Ethology (Klopfer, P.H., and Bateson, P.G., eds), pp. 31 l-332, Plenum 3 Schoener, T.W. (1986) Am. Zoo/., 26, 81-106 4 Pulliam, H.R. (1986) Am. Zoo/., 26,71-80 5 Moermond, T.C. (1986) Am. Zoo/., 26, 23-38 6 Price, M.V. (1986) Am. Zoo/., 26,3-4 7 Roughgarden, J. (1983) Am. Nat., 122, 583-601 8 Strong, D.R., Jr (1983) Am. Nat., 122. 636-660
MonographingNatural
HoneybeeEcology by Thomas D. Seeley, Princeton University Press, 7986. f28.40 hbk Ix + 207 pages) ISBN 0 69 108397 6 Ecology is a hungry discipline, consuming others at a fast rate. Originally physiological in nature, it now covers almost everything concerned with whole-organism it has been defined as biology; ‘scientific natural history’. Honeybee Ecology is a wellwritten summary of the ecology of the genus Apis, and concentrates for obvious reasons upon A. mellifera. In keeping with that laudable recent tendency among academic field biologists of openly admitting in print our enjoyment of natural history and love of our study animals, Thomas Seeley communicates his enthusiasm for honeybees in a very effective and natural manner. ‘The honeybee is a wonderful example of adaptation’ is his opening line, and he follows it with numerous engaging extravagances: the honeybee is an ‘extremist’, we learn, and in its communidation ‘is unsurpassed among animal communication systems in its capacity for coding precise yet flexible messages’ (note animal not insect). This is as it should be; any ecologist without such a crush on his/her organism is a Scrooge indeed. Seeley’s aim is to redress the im-
balance he sees between the multitudinous studies of how honeybee societies work from a physiological and mechanistic standpoint, and the few investigations that consider how natural selection has shaped their social system. In doing this, he takes us through chapters on the evolutionary origin of the genus and its domestication, the structure of the colony, its annual cycle, reproduction, nest-site selection and nest construction, the collection of food, temperature control and colony defence, concluding with a comparison between the various races and species of the genus. The text is strongest, naturally, in areas where Seeley himself has carried out much of the work to which he alludes. I like particularly the parts that deal with honeybee natural history, society structure and the annual cycle, colony foraging, defence, and thermoregulation. Surprisingly, the chapter comparing different races and species works less well. In the case of the interspecific comparisons, I suspect it is partly because of the odd perspective of trying to explain why they are different sizes. Apis dorsata has a body mass of about 155 mg, whereas A. florea is only 32 mg. Such questions are of course at the heart of ecological explanations, but I feel that not much is gained by their use here. For example, the discussion of equilibria1 body temperature is inadequate, nowhere are there any data, and it adds nothing to the story. Simplistic formulations also appear in the section on feeding, where the theory of central-place foraging is used to illustrate the assessment of patches. I find the argument here very unconvincing, and some obvious points are missing. For example, Seeley regards as ‘unclear’ why the maximum volume of nectar in the crop is unrelated to
sugar concentration (a point that is well-documented in the uncited superb work’ of Andreas Bertsch on bumblebees), but increases as patch time decreases and travel time increases. The latter must be related to the cost of flying with a laden crop: recent work (with honeybees) has shown that crops are not always filled to capacity. I have chosen to illustrate these examples not to pick holes in what is said, but to show that Seeley may not have achieved his aim. He is trying to bring evolutionary ideas to honeybee ecology: in the attempt, I think he warps slightly the good work he does in the bulk of the text. While we have all heard too much about the ‘Panglossian paradigm’ of the adaptationist programme, it is relevant here. Trying to fit optimality models to everything results in some misfits, for instance in Seeley’s sections on life-history traits and the discussion of the costs and benefits of defence. This is a good book, and very enjoyable to read. Much of it is really the ‘scientific natural history’ of honeybees, which sometimes fits badly onto the Procrustean bed of insistent evolutionary thinking. Many valuable insights into behaviour and ecology have of course been adduced from our current genetical understanding of bees, and Seeley describes these very well and makes much of them. As someone once said to me, perhaps one day academic ecologists will once again feel proud to write books entitled ‘The natural history of. .‘. Francis S. Gilbert Department ofZoology.Nottingham University, Nottingham NG7 2RD. UK Reference 1 Bertach, 325336
A. (1984)
Oecologia, 62,