查看更多>>摘要：The diversity of secondary sexual signals across animals has led evolutionary biologists to hypothesize an important role for sexual selection in the process of speciation. Testing this hypothesis typically focuses on male female mating interactions and divergence in female mate preferences between populations, leading to behavioural reproductive isolation. While informative, these tests rarely account for the potential contributions of male male competitive interactions and male mate preferences to speciation. By incorporating male and female behavioural data across a genus of colourful freshwater fishes (Percidae: Etheostoma), our results suggest coevolution between male signals and aggressive responses and a potential role for male mating biases alongside female mating biases in the evolution of behavioural isolation between allopatric species. These surprising results imply an important function for male behaviours in trait divergence and the evolution of reproductive isolation, suggesting that a broader view of sexual selection is vital to addressing its role in speciation. (C) 2015 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved.
查看更多>>摘要：Noise pollution is a world-wide phenomenon and its effects on animal behaviour have been investigated by numerous studies focusing mostly on vertebrate taxa. However, studying how insects are impacted by human-made noise is indispensable, because of their ecological importance and in order to gain a more comprehensive knowledge of how animals can cope with this new challenge. The few studies that have examined the effects of noise pollution on the acoustic signalling of insects have characterized noise over long timescales. In this study we examined whether males of the tree cricket Oecanthus pellucens modify their calling song in response to the fluctuation in traffic noise over a short timescale. To examine this question we carried out (1) noise level measurements over a short time window (200 ms) paired with song parameter measurements on sound recordings of males singing in their noise-polluted habitats and (2) laboratory playback experiments in which each singing male was recorded during a silent control period and during noise playback. Our results show that males shortened their calls (echemes) and paused singing with a higher probability with increasing noise level. However, males did not modify the fundamental frequency of their song and did not adjust the duration of the interecheme interval in response to noise. These results suggest that crickets decrease signalling effort during high levels of noise and, at least for the song parameters we examined, do not modify their signals, as do birds and frogs, to reduce masking by anthropogenic noise. (C) 2015 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved.
查看更多>>摘要：Avian brood parasites lay their eggs in the nests of other species, imposing high costs on their hosts. In theory, this should select for the evolution of defences against parasitism in hosts, yet eviction of parasite eggs or chicks is absent in many host species. One such host is the yellow-rumped thornbill, Acanthiza chrysorrhoa, the primary host of the shining bronze-cuckoo, Chalcites lucidus, in Australia. Here we tested whether the lack of egg and chick rejection in yellow-rumped thornbills has led to the evolution of alternative defences against brood parasitism. We provide evidence that this host has evolved two types of frontline defences. First, yellow-rumped thornbills responded to the presence of a cuckoo mount near the nest with mobbing behaviour and by occupying their dome-shaped nests, potentially as a means of blocking the small entrance hole. Second, we show that brood parasitism imposes directional selection for early breeding on the yellow-rumped thornbill and that yellow-rumped thornbills show a concomitant shift in their breeding phenology, breeding earlier than both congeneric and sympatric species. Our results highlight the importance of studying apparently defenceless hosts in order to identify alternative defence strategies. (C) 2015 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved.
Street, Sally E.Cross, Catharine P.Brown, Gillian R.
203-212页
查看更多>>摘要：In some species of Old World monkeys and apes, females exhibit exaggerated swellings of the anogenital region that vary in size across the ovarian cycle. Exaggerated swellings are typically largest around the time of ovulation, and swelling size has been reported to correlate positively with female quality, supporting the hypothesis that exaggerated swellings are honest signals of both female fecundity and quality. However, the relationship between swelling size and timing of ovulation is weak in some studies, and the relationship between swelling size and female quality has also not been consistently reported. Here, we collated empirical studies that have reported either swelling size and estimated timing of ovulation (N = 26) or swelling size and measures of individual quality (N = 7), to assess the strength of these relationships using meta-analytical methods. Our analyses confirmed that the period of maximal swelling size is closely associated with the most fertile period of the ovarian cycle and that a large proportion of ovulations occur during the maximal swelling period. A small, positive effect size was also found for the relationship between swelling size and body condition. In contrast, the relationships with age and social rank were not significant. Swelling size, therefore, potentially signals both female condition and timing of the fertile phase. Males are likely to benefit from allocating mating effort according to swelling size, while females with large swellings potentially benefit from exerting control over matings in species in which female control is compromised by male mating strategies. (C) 2015 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved.
Silla, Aimee J.McInerney, Emma P.Byrne, Phillip G.
213-220页
查看更多>>摘要：Nutritional conditions experienced by an individual are known to affect phenotype and performance. In particular, dietary carotenoids influence vertebrate immune function, vision and coloration and have recently been suggested to enhance exercise performance. Despite growing interest in investigating the effect of dietary carotenoids on exercise performance, studies to date have been limited to short-term supplementation during a single life stage. The present study elucidates, for the first time, the effect of long-term carotenoid supplementation during both developmental and adult life stages on the aquatic and terrestrial escape performance of adult southern corroboree frogs, Pseudophryne corroboree, testing the predictions of the 'environmental matching' and the 'silver spoon' hypotheses. Individuals (N = 24 per treatment) were exposed to one of four dietary treatments: (1) both developmental and adult life stages were fed a carotenoid-supplemented diet (C-C); (2) developmental life stage, but not adult life stage, was fed a carotenoid-supplemented diet (C-U); (3) adult life stage, but not developmental life stage, was fed a carotenoid-supplemented diet (U-C); (4) both developmental and adult life stages were fed an unsupplemented diet (U-U). There was no effect of dietary carotenoids on swimming speed, hopping speed or righting ability. However, our results do indicate an effect of carotenoid supplementation on both swimming distance and hopping distance. Frogs receiving a carotenoid-supplemented diet during both developmental and adult life stages consistently outperformed other dietary treatments in the distance travelled during aquatic and terrestrial escape trials. Our results do not show support for either the silver spoon or the environmental matching hypothesis, but indicate an overall benefit of exposure to a carotenoid-rich environment across both life stages. (C) 2015 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved.
查看更多>>摘要：Host selection in parasitoids can be influenced by learning cues obtained during natal and/or adult experience. We investigated the effects of natal and adult host experience on host selection by the indigenous parasitoid Necremnus tutae (Hymenoptera: Eulophidae), with an exotic host, the invasive tomato leafminer, Tuta absoluta (Lepidoptera: Gelechiidae), and a native host, Cosmopterix pulchrimella (Lepidoptera: Cosmopterigidae). Colonies of the parasitoid N. tutae were reared on the exotic host T. absoluta and the native host C. pulchrimella, infesting tomato and upright pellitory plants, respectively. Six groups were obtained based on their rearing histories (T. absoluta or C. pulchrimella larvae) and adult experience (no exposure to host larvae or oviposition experience on the two host species). Parasitoid females of the six groups were tested for behavioural responses to the two host plant complexes (HPCs) in Y-tube olfactometer assays and in two-choice assays in test arenas. The results suggest that host experience during both natal and adult life may affect the HPC preference of this parasitoid species. In particular, adult experience proved to influence the host preference in both olfactometer and two-choice assays. By contrast, natal experience showed a significant influence on host choice only in naive parasitoid females in the olfactometer bioassays. In general, the exotic host T. absoluta tomato complex was the odour source preferred by the parasitoid N. tutae. The role of natal and adult experience in host shifting dynamics and how these experiences can combine in adapting mechanisms to a new exotic insect of a generalist parasitoid species are also discussed. (C)2015 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved.
查看更多>>摘要：Intense intrasexual competition for breeding opportunities is a characteristic of cooperatively breeding species with high reproductive skew. In such 'singular' cooperative breeders, females suffer greater variability in direct reproductive success than do males, and this in turn leads to greater intrasexual competition in females. Under such circumstances, selection should favour traits that enhance female competitive ability, such as size, fighting skill or aggression. However, despite burgeoning interest in female intrasexual competition, there is limited evidence that female cooperative breeders exhibit more pronounced competitive traits than do males. We examined whether intrasexual competition has influenced the expression of a competitive behavioural trait (i.e. prey theft) in a 'singular', cooperatively breeding mammal, the dwarf mongoose, Helogale parvula. We used both observational and experimental data to assess whether wild dwarf mongooses exploit interference foraging competition to persecute their reproductive rivals, and whether the sexes differ with regard to this behaviour. We found that nonalpha female mongooses preferentially stole from other females rather than males, and that, under natural foraging conditions, they were more likely to steal prey from their closest rival (i.e. the female immediately below themselves in the dominance hierarchy) than from easier targets much lower in rank. In contrast, male dwarf mongooses (and alpha females) did not exhibit any sex bias, stealing prey indiscriminately from all lower ranking group members. We conclude that the acute intrasexual rivalry suffered by female dwarf mongooses has led to the differential development of this competitive behavioural trait. (C) 2015 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved.
查看更多>>摘要：The existence of discrete social clusters, or 'communities', is a common feature of social networks in human and nonhuman animals. The level of such community structure in networks is typically measured using an index of modularity, Q. While modularity quantifies the degree to which individuals associate within versus between social communities and provides a useful measure of structure in the social network, it assumes that the network has been well sampled. However, animal social network data is typically subject to sampling errors. In particular, the associations among individuals are often not sampled equally, and animal social network studies are often based on a relatively small set of observations. Here, we extend an existing framework for bootstrapping network metrics to provide a method for assessing the robustness of community assignment in social networks using a metric we call community assortativity (r(com)). We use simulations to demonstrate that modularity can reliably detect the transition from random to structured associations in networks that differ in size and number of communities, while community assortativity accurately measures the level of confidence based on the detectability of associations. We then demonstrate the use of these metrics using three publicly available data sets of avian social networks. We suggest that by explicitly addressing the known limitations in sampling animal social network, this approach will facilitate more rigorous analyses of population-level structural patterns across social systems. (C) 2015 The Authors. Published on behalf of The Association for the Study of Animal Behaviour by Elsevier Ltd. This is an open access article under the CC BY license
查看更多>>摘要：Although one of the hallmarks of personality traits is their consistency over time, we might expect personality traits to change during life history shifts. Becoming a parent is a major life history event, when individuals undergo dramatic behavioural and physiological changes. Here we employ a longitudinal experiment to ask whether personality changes in response to the experience of parenting in male threespine sticklebacks, Gasterosteus aculeatus. Life history theory predicts that males should be less risk averse after successfully parenting, and the neuroendocrinology of parenting suggests that parenting could reorganize the hormonal landscape and behaviour of fathers. We randomly assigned males to either an experimental group (reproduced and parented) or a control group (did not reproduce and parent), and repeatedly measured a personality trait ('boldness') and 11-ketotestosterone levels (11-kT, the major androgen in fishes) in individual males. In the control group, males became bolder over time. However, in the experimental group, boldness did not change. Furthermore, 11-kT changed dramatically in the experimental group, and changes in 11-kT in parents were associated with boldness after parenting ceased. Our study is one of the first to assess proximate and ultimate explanations for changes in personality as a function of reproduction and parenting. (C) 2015 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved.
Stanley, Calandra Q.Walter, Michael H.Venkatraman, Madhvi X.Wilkinson, Gerald S....
255-265页
查看更多>>摘要：Many species of birds conspicuously call or sing early in the morning, thereby creating an avian dawn chorus. While these vocalizations probably function to advertise territory occupancy, when species should start singing is not well understood. A common explanation is that birds sing at dawn to maximize signal transmission due to low atmospheric turbulence during the early morning (acoustic transmission hypothesis); however, this idea does not explain why species in the chorus often start singing at different times. Here we test a version of this hypothesis: interspecific differences in call start times during the dawn chorus are a result of noise avoidance at the song's frequency. To test this hypothesis we quantified the spectral and temporal properties of the dawn chorus and the acoustic landscape at Barro Colorado Island, Panama. Inspection of 36 dawn recordings at 12 sites identified 27 species of birds, with most species having consistent start times across sites and days. In contrast to expectations, we found that birds singing within the same frequency range did not temporally partition acoustic space during the chorus. Discriminant function analysis revealed that nearly all species in the chorus produced distinctive vocalizations. Surprisingly, song start time was positively related to peak frequency. Birds with high-frequency vocalizations did not begin singing until after orthopteran insects stopped producing loud sounds at the same frequencies. These results suggest that birds that sing at frequency bands shared by nocturnal insects avoid acoustic masking by delaying song start times. Playbacks of emerald cicada, Zammara smaragdina, buzzes conducted during the dawn chorus produced an inhibitory effect on the call activity of birds singing within the bandwidth of cicada calls. Thus, insect noise appears to create an important frequency-dependent constraint on the calling activity of birds. This constraint is overcome by temporal partitioning of acoustic space. (C) 2015 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved.
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