Vetter, Sebastian G.Brandstaetter, ConstanzeMacheiner, MarieSuchentrunk, Franz...
193-205页
查看更多>>摘要：There is increasing evidence that animal personalities are linked to different life history strategies. However, studies examining whether these effects differ under varying environmental conditions are rare. Here, we investigated how animal personality affects reproductive success in a pulsed resource consumer, the wild boar. We determined the exploratory behaviour of 57 female wild boars in nine novel object tests and additionally assessed their aggressiveness. Exploration behaviour (i.e. approach latency and investigation duration) and aggressiveness were repeatable within individuals and both mapped on a single principal component yielding an individual personality score. Afterwards the females were kept together with 28 males under seminatural conditions in two large breeding enclosures from 2011 to 2014. Over winter 2013/2014 we applied high versus medium feeding regimes to the two enclosures. Our results show that adult body mass and reproductive success were affected by juvenile body mass and thus already determined early in life, which may point to a silver spoon effect in the wild boar. Whether a female reproduced or not, as well as the litter size shortly after birth, was only affected by female body mass. The postweaning litter size (i.e. at the time of independence at the age of about 6 months), however, was additionally affected by the personality score in interaction with food availability. Under high food availability less aggressive and explorative individuals raised more juveniles to independence. We conclude that lower aggressiveness and reduced exploratory tendency of the mother lead to lower juvenile mortality and hence have a positive impact on postweaning litter size. Under slightly decreased food availability, however, this effect vanished. As the impact of personality on reproductive success differed between changing environmental conditions, our results support the hypothesis that different personality phenotypes are evolutionarily maintained by varying selection pressures in heterogeneous environments. (C) 2016 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved.
Verspoor, Rudi L.Hurst, Gregory D. D.Price, Tom A. R.
207-215页
查看更多>>摘要：Females are expected to avoid low-quality males fathering their offspring. X chromosome meiotic drive (XCMD) makes males very low-quality mates. XCMDs are X chromosomes that, in males, cause the failure of all Y chromosome sperm, so all functional sperm carry the driving X and produce daughters. This transmission advantage can allow the XCMD to spread through populations. However, XCMD males typically have low fertility, are very poor at sperm competition, only produce daughters, and bear low fitness alleles associated with XCMD. This imposes significant costs on females that mate with these males. Recently, several studies have shown that females can reduce the risk of their offspring inheriting XCMDs by mating with multiple males (polyandry), as XCMD males typically lose out to normal males in sperm competition. Hence it has been suggested that increased polyandry may be likely to evolve whenever a costly XCMD is common in a population, and that polyandry may be a key factor in preventing XCMDs spreading through populations. We tested this by examining the fruit fly Drosophila subobscura, in which females are known to mate only once in European populations where XCMDs are absent. However, in North African populations an XCMD, referred to as 'SRs', occurs. If the association between XCMDs and polyandry is true, then these North African populations should have evolved polyandry. However, we found no evidence of polyandry in North African D. subobscura populations. Instead, we found some evidence that males that carry SRs are slightly less successful at gaining matings in noncompetitive situations. These results show that polyandry does not necessarily evolve in response to the presence of harmful X chromosome drive. With both sperm competition and female choice both being unlikely to substantially reduce the success of XCMD in D. subobscura, the factors that prevent SRs spreading through these populations remain mysterious. (C) 2016 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved.
查看更多>>摘要：Decomposition of vertebrate carrion is partially due to microbes, which release a series of volatile organic compounds (VOCs) at various concentrations. These VOCs are part of ecologically relevant public information that serve as cues attracting blow flies (Diptera: Calliphoridae), such as Lucilia sericata, to remains as a resource both for themselves and for their offspring. However, these responses are partially governed by sex and physiological state (e.g. gravid and nongravid) of the fly and concentration of the VOCs. We examined the responses of 7-9-day-old L. sericata adults to dimethyldisulphide, indole, isobutylamine and phenylacetic acid in a Y-tube olfactometer. These VOCs are associated with vertebrate decomposition, carrion-mimicking flowers as well as fly-attracting bacteria. Our results demonstrate a relationship between sex and physiological state with regard to dose-dependent attraction to VOCs that occur during decomposition, suggesting that specific decomposition molecules provide distinct types of information to the flies with differing foraging interests. Understanding this dynamic relationship provides insight into the mechanisms regulating arthropod colonization, competition and resulting succession in association with such ephemeral resources. (C) 2016 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved.
Wallen, Megan M.Patterson, Eric M.Krzyszczyk, EwaMann, Janet...
227-236页
查看更多>>摘要：Sexual coercion results from extreme conflict over mating. As a male strategy to overcome female resistance, coercion can impose fitness costs on females. Among mammals, most cases involve single males or temporary coalitions, with allied aggression towards females being rare. Among Shark Bay bottlenose dolphins, Tursiops cf. aduncus, male alliances harass, guard and consort with females to obtain mating access, which has known physical costs to females. However, the behavioural and ecological costs of sexual coercion to females remain largely unexplored. Given the importance of individual differences in ranging and habitat use for dolphin foraging ecology, social networks and fitness, we hypothesized that male coercion also imposes ecological costs on females. Using 25 years of longitudinal data, we examined how adult male presence relates to female space use, and we found that females (N = 32) altered their ranging when associating with adult males but also when they were cycling. Additionally, females reduced the use of their primary (preferred) habitat when with males, but cycling had no effect. Ranging shifts were slightly greater for males than for females when they were together, but only for females did this alter their spatial ecology. While it is also possible that males follow fertile females and/or that females move to avoid males, the well-documented coercive mating system suggests that males, as part of their coercive mating tactics, sequester females to areas that females would not otherwise occupy. Our results show that in a coercive mating system, males can alter females' basic behavioural ecology, and suggest that males spatially sequester individual females via allied consortships. (C) 2016 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved.
Cook, Chelsea N.Kaspar, Rachael E.Flaxman, Samuel M.Breed, Michael D....
237-243页
查看更多>>摘要：Social insect societies maintain homeostasis through decentralized collective effort. In quickly changing environments, homeostasis can be difficult, as information may promptly become outdated. How do decentralized social insect groups respond to rapid environmental changes? Honeybee (Apis mellifera L.) workers use thermoregulatory fanning behaviour as part of their repertoire to maintain nest temperatures below 36 degrees C, as larvae can develop malformations and die if temperatures surpass this threshold. Here, we determine whether honeybees alter their fanning behaviour when experiencing different rates of thermal change. We found that honeybee fanners were significantly more likely to fan when experiencing rapidly increasing temperatures, but this response was only seen in larger groups of bees. Additionally, fanners responded at significantly lower temperatures when temperatures were increased quickly, but again, only when they were in larger groups. Our results show a statistically significant interaction between fanning response and group size. These findings illustrate the importance of exploring both response thresholds and probability of response of animals in social groups experiencing changing environments, as both factors affect homeostatic responses. Understanding how self-organized animal societies maintain homeostasis provides insight into decentralized organization across many biological systems. (C) 2016 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved.
Armansin, N. C.Lee, K. A.Huveneers, C.Harcourt, R. G....
245-258页
查看更多>>摘要：Many shark species form groups; yet the drivers of this behaviour are not well understood. Aggregations have been presumed to be a function of resource availability or phenology. However, recent studies have suggested that some sharks display preferences in their associations with conspecifics and that complex social networks may underpin their movement patterns, demographic distribution and fitness. This study used a network approach to investigate patterns of sociality of a benthic predator, the spotted wobbegong shark, Orectolobus maculatus (Family Orectolobidae), in a small marine reserve. Spatial data obtained from fine-scale passive acoustic telemetry were used to infer association preferences of 15 tagged sharks over a 15-month period. Thirty-five associating dyads emerged, with permutation tests indicating that these were nonrandomly formed. Many dyads were temporally stable, with some persisting even after sharks returned to the reserve from their seasonal migration. A complete but sparse network was observed and although association patterns were evident at the dyadic level, indication of stable communities or network structure was limited. The population was not found to be gregarious and exclusive pairs were not observed, with 14 sharks associating with more than one individual. Assortative mixing (by sex, size and familiarity) was not present and range overlap did not strongly correlate with association indices. This suggests that these relationships are not a random result of nonsocial grouping behaviours but can be explained, at least in part, by genuine social affiliation. As such, anthropogenic influences on the population may have more complex impacts than previously thought. (C) 2016 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved.
查看更多>>摘要：Dominance hierarchies emerge when individuals must compete for access to resources such as food, territory or mates. Here, using traditional and network social hierarchy analysis, we show that 10 groups of 12 male laboratory CD1 mice living in large vivaria consistently form extremely linear dominance hierarchies. Within each hierarchy we determine that every individual mouse has a unique social rank and behaves with a high degree of consistency in their agonistic behaviour towards other individuals. Using temporal pairwise comparison Glicko ratings and social network triangle transitivity measures, we demonstrate that these hierarchies emerge rapidly, and that initial aggression is not predictive of later dominance. We also show that groups vary in how unequally power is distributed over time as social networks stabilize. Our results demonstrate that an ethologically relevant housing paradigm coupled with extensive behavioural observations provides a strong framework for investigating the temporal patterning of mouse dominance hierarchies and complex social dynamics. Furthermore, the statistical methods described establish a strong basis for the study of temporal dynamics of social hierarchies across species. (C) 2016 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved.
查看更多>>摘要：Males of several species have been shown to alter their mate preference in the presence of an eavesdropping rival. This evasive tactic has been interpreted as an attempt by the courting male to drive the attention of the rival away from the preferred female. The fitness return of this deceptive strategy will depend on the costs of cheating for the actor (the displayer) and the benefits for the rival (the bystander) of copying the choice of the displayer. We developed a two-person nonzero sum game between two males that compete for mating with one of two receptive females. Males could assess female quality with a varying level of uncertainty, which was modelled using a Bayesian statistical decision theory approach. We explored the actor and bystander payoffs under different levels of uncertainty in mate assessment and difference in quality between females. We found that when being eavesdropped on is costly (i.e. when females differ largely in quality), males are expected to cheat to reduce the amount of public information that is available to the unintended audience. However, under these circumstances, the value of the public information is low and the bystander is not expected to copy the choice of the actor. Our model suggests that deceptive male choice may evolve only under relatively restricted conditions and suggest that other explanations, such as, for example, a reduction in the risk of precopulatory male-male competition may be more likely. Future theoretical and empirical work will be necessary to test alternative interpretations of the audience effects in male mate choice. (C) 2016 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved.
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