Sih, A., Bell, A., & Johnson, J. C. (2004). Behavioral syndromes: an ecological and evolutionary overview. Trends. Ecol. Evol, 19(7), 372–378.
Abstract: Recent studies suggest that populations and species often exhibit behavioral syndromes; that is, suites of correlated behaviors across situations. An example is an aggression syndrome where some individuals are more aggressive, whereas others are less aggressive across a range of situations and contexts. The existence of behavioral syndromes focuses the attention of behavioral ecologists on limited (less than optimal) behavioral plasticity and behavioral carryovers across situations, rather than on optimal plasticity in each isolated situation. Behavioral syndromes can explain behaviors that appear strikingly non-adaptive in an isolated context (e.g. inappropriately high activity when predators are present, or excessive sexual cannibalism). Behavioral syndromes can also help to explain the maintenance of individual variation in behavioral types, a phenomenon that is ubiquitous, but often ignored. Recent studies suggest that the behavioral type of an individual, population or species can have important ecological and evolutionary implications, including major effects on species distributions, on the relative tendencies of species to be invasive or to respond well to environmental change, and on speciation rates. Although most studies of behavioral syndromes to date have focused on a few organisms, mainly in the laboratory, further work on other species, particularly in the field, should yield numerous new insights.
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Lima, S. L. (1986). Predation Risk and Unpredictable Feeding Conditions: Determinants of Body Mass in Birds. Ecology, 67(2), 377–385.
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Murray, M. G., & Brown, D. (1993). Niche Separation of Grazing Ungulates in the Serengeti: An Experimental Test. T. J. Anim. Ecol., 62(2), 380–389.
Abstract: 1. The niche separation of three species of alcelaphine antelope (wildebeest, topi and hartebeest) with similar body size was compared by measuring bite weight, bite rate, intake rate and selectivity of tame animals in plots containing grass at different growth stages. 2. On growing swards, hartebeest had a smaller bite weight and lower intake rate, and were also less selective of green leaf, than either topi or wildebeest. On senescent swards, hartebeest were more selective of leaf than the other two species. 3. Wildebeest had a faster bite rate than either topi or hartebeest on swards with low biomass and high protein content of green leaf (green flush). Bite weight and intake rate of wildebeest and topi were similar despite the difference in breadth of their incisor rows. 4. Topi were significantly more selective of green leaf than the other two species and were the only species to maintain a rapid bite rate on swards with high green leaf biomass. 5. The feeding experiments did not reveal significant cross-overs between species in the rate of food intake on different grass types, but each species was most proficient either in leaf selection or bite rate when feeding on grass swards in a particular growth stage. We suggest that growth stage is a primary determinant of niche separation. 6. In Serengeti, grazing ungulates which migrate are specialists of the earlier growth stages of grass which tend to be transient, while those that are residential specialize on late growth stages which are more enduring. The mobility of species, and the spatial and temporal dynamics of pastures containing different growth stages of grass, contribute to niche separation.
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Negi, G. C. S., Rikhari, H. C., Ram, J., & Singh, S. P. (1993). Foraging Niche Characteristics of Horses, Sheep and Goats in an Alpine Meadow of the Indian Central Himalaya. J. Appl. Ecol, 30(3), 383–394.
Abstract: 1. Data on plant species foraged, foraging hours, bite rate, bite size and species dry matter (DM) removed per species per bite were collected in tussock grass-forb (Grass-F), forb-tussock grass (Forb-G), Trachydium-forb (Forb), Rhododendron-Cassiope and early successional communities from May to September in a moderately foraged Central Himalayan alpine meadow in order to study the foraging niche characteristics of horses, sheep and goats. 2. The three animals together grazed 30 plant species, of which 20 were grazed by horses, 22 by sheep and 16 by goats. 3. The average foraging hours (5.2-13.2), bites per minute (23-51) and mg DM per bite (59-99) for horses, sheep and goats were significantly different in different communities and months. 4. The foraging search cost, reckoned as distance walked per unit DM eaten, was highest for goats (15.4 km kg$^{-1}$), followed by sheep (8.1 km kg$^{-1}$) and horses (1.2 km kg$^{-1}$). 5. Of the total intake of horses (3.25 kg DM day$^{-1}$), the Forb community alone accounted for 40%. Sheep (0.74 kg DM day$^{-1}$) resembled horses in this respect. In contrast, the contribution of this community was negligible in the diet of goats in which the Grass-F community contributed most to the intake. 6. Forbs were the largest dietary category for all animal species. The selection ratio varied from 0.7 to 11.3 for forbs, 1.0 to 7.2 for sedges and 1.1 to 2.5 for grasses. 7. Response breadth (in terms of species grazed) was similar for horses and sheep (0.46 vs. 0.43) and somewhat wider for goats (0.49). 8. Grazing pressures below the carrying capacity of the community appeared to favour botanical diversity.
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Meriggi, A., Dagradi, V., Dondina, O., Perversi, M., Milanesi, P., Lombardini, M., et al. (2014). Short-term responses of wolf feeding habits to changes of wild and domestic ungulate abundance in Northern Italy. Ethology Ecology & Evolution, 27(4), 389–411.
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McGregor, P. K., & Dabelsteen, T. (1976). Communication Networks. In D. E. Kroodsma, & E. H. Miller (Eds.), Ecology and evolution of acoustic communication in birds (pp. 409–425). Ithaca: Cornell University Press.
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Zuberbühler, K. (2001). Predator-specific alarm calls in Campbell's monkeys, Cercopithecus campbelli. Behav. Ecol. Sociobiol., 50(5), 414–422.
Abstract: One of the most prominent behavioural features of many forest primates are the loud calls given by the adult males. Early observational studies repeatedly postulated that these calls function in intragroup spacing or intergroup avoidance. More recent field experiments with Diana monkeys (Cercopithecus diana) of Taï Forest, Ivory Coast, have clearly shown that loud male calls function as predator alarm calls because calls reliably (1) label different predator classes and (2) convey semantic information about the predator type present. Here, I test the alarm call hypothesis another primate, the Campbell's monkey (C. campbelli). Like Diana monkeys, male Campbell's monkeys produce conspicuous loud calls to crowned hawk eagles (Stephanoaetus coronatus) and leopards (Panthera pardus), two of their main predators. Playback experiments showed that monkeys responded to the predator category represented by the different playback stimuli, regardless of whether they consisted of (1) vocalisations of the actual predators (crowned hawk eagle shrieks or leopard growls), (2) alarm calls to crowned hawk eagles or leopards given by other male Campbell's monkeys or (3) alarm calls to crowned hawk eagles or leopards given by sympatric male Diana monkeys. These experiments provide further evidence that non-human primates have evolved the cognitive capacity to produce and respond to referential labels for external events.
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Mesterton-Gibbons, M., & Dugatkin, L. A. (1995). Toward a theory of dominance hierarchies: effects of assessment, group size, and variation in fighting ability. Behav. Ecol., 6(4), 416–423.
Abstract: We introduce assessment to the analysis of dominance hierarchies by exploring the effect of an evolutionarily stable fighting rule when there is variation in resource holding potential (RHP) and RHP is not a perfectly reliable predictor of the outcome of a fight. With assessment, the probability of a linear hierarchy decreases with group size but can remain appreciable for groups of up to seven or eight individuals, whereas it decreases virtually to zero if there is no assessment. The probability of a hierarchy that correlates perfectly with RHP is low unless group size is small.
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Purvis, A. (2006). The h index: playing the numbers game. Trends. Ecol. Evol, 21(8), 422.
Abstract: Article Outline
References
The ‘h index’ was developed recently as a measure of research performance [1]: a researcher's h is the number of his or her papers that have been cited at least h times. In their thoughtful critique of the index, Kelly and Jennions [2] point out many ways in which h is no better than ‘traditional’ bibliometrics, such as total citation counts. However, there is one way in which, for researchers, it could be very much better, especially if (as Hirsch suggests [1]) it is to inform hiring and promotion decisions. The skewed nature of the distribution of citations among publications means that most researchers have several papers that nearly but not quite count. Consequently, h can be distorted much more easily than can total citation count just by finding a subtle way to cite one's own papers that are ‘bubbling under’. Incidentally, bats show broadly the same life-history allometries as other mammalian clades [3].
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Ginsberg, J. R., & Rubenstein, D. I. (1990). Sperm competiton and variation in zebra mating behaviour. Behav. Ecol. Sociobiol., 26(6), 427–434.
Abstract: Data are presented on the breeding behavior of two zebra species to test whether intra- and interspecific variation in male reproductive behavior and physiology are correlated with differences in female promiscuity. In one species, plains zebra (Equus burchelli) females live in closed membership single male groups and mate monandrously. In the other species, the Grevy's zebra (E. grevyi) females live in groups whose membership is much more temporary. Typically, associations with individual males are brief and mating is polyandrous. However, some females – those having just given birth – reside with one male for long periods, mating monandrously. These differences in female mating behavior generate variability in the potential for sperm competition. We show that behavioral differences in male investment in reproductive activities correlate with the potential for sperm competition. When mating with promiscuous mares, Grevy's zebra stallions made a greater investment in reproductive behavior (calling, mounting, ejaculations) than did stallions of either species when mating with monandrous females. The evolution of large testes size in the Grevy's zebra, when compared to the congeneric plains zebra, horse, and mountain zebra, allows for this increased investment.
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