Authors:Masaru Hasegawa; Emi Arai First page: 835 Abstract: Source: Volume 154, Issue 7-8, pp 835 - 851Pair formation is indispensable for breeding in monogamous species, generating selection for male traits that increase the probability of pairing success. Male ornamentation is one such trait, and several empirical studies have shown the importance of each of multiple ornaments. Still, it remains unclear how multiple ornaments in combination affect the probability of pair formation. Using the Japanese barn swallow, Hirundo rustica gutturalis, we studied the interplay of two sexually selected male traits, tail length and throat coloration, during pair formation. Independent of other morphological, ornamental and abiotic variables, the probability of pair formation was predicted by the negative interplay between tail length and plumage colour saturation: males possessing more-colourful plumage with shorter tails or males possessing less-colourful plumage with longer tails had a higher probability of pair formation than others. The current findings may explain spatiotemporal variation in ornamentation and sexual selection in this model species. PubDate: 2017-08-31T00:00:00Z
Authors:Margherita Corti; Gaia Bazzi, Alessandra Costanzo, Stefano Podofillini, Nicola Saino, Diego Rubolini Andrea Romano First page: 853 Abstract: Source: Volume 154, Issue 7-8, pp 853 - 874Consistent and correlated inter-individual differences in behaviours, the so-called ‘personalities’, have been identified in many vertebrates. The ability to respond to stressful events is part of personalities and can have important fitness consequences, as it determines how individuals cope with environmental challenges. As a consequence of pleiotropic effects of genes involved in several functions, inter-individual differences in behavioural responses can be associated with phenotypic traits, like melanin-based plumage colouration in birds. We examined the association between three proxies of the behavioural stress response and breast plumage colouration in barn swallow (Hirundo rustica) nestlings. We found that nestling behavioural responses were consistent within individuals and similar among siblings, thus suggesting that these behaviours may contribute to define individual ‘personalities’. However, nestling behavioural stress response was not significantly predicted by variation in breast plumage colouration, indicating that in juveniles of this species melanin-based colouration does not convey to conspecifics reliable information on individual ability to cope with stressful events. PubDate: 2017-08-31T00:00:00Z
Authors:Erica S. Dunayer; Carol M. Berman First page: 875 Abstract: Source: Volume 154, Issue 7-8, pp 875 - 907Throughout the primate order, individuals are highly motivated to handle infants that are not their own. Given the differing and often conflicting interests of the various participants in handling interactions (handler, infant, and mother), most functional hypotheses are specific to particular handling roles. Here we explore one hypothesis that may apply to all participants, but that has received relatively little attention: that handling may facilitate the formation and maintenance of social bonds. Using free-ranging rhesus macaques (Macaca mulatta) on Cayo Santiago, we examine the relationship between infant handling in the early weeks and the strength and diversity of infant social bonds months later, when infant relationships were more independent from those of their mothers. Our results largely confirm the influence of several social characteristics (kinship, rank, sex, and age) in governing handling interactions. They also provide the first evidence that early handling is associated with later social bonds that are stronger than expected based on these social characteristics. However, the enhancement of bonds is largely confined to related handlers; frequent unrelated handlers did not generally go on to form strong bonds with infants. This suggests that kinship may be a sort of prerequisite to the enhancement of social bonds via handling. Given the adaptive benefits of strong social bonds among adult primates, future research should investigate whether early infant handling may have longer term fitness effects. PubDate: 2017-08-31T00:00:00Z
Authors:Douglas A. Nelson; Ben M. Nickley, Angelika Poesel, H. Lisle Gibbs John W. Olesik Abstract: Source: Page Count 26Dispersal in birds can have an important influence on the genetic structure of populations by affecting gene flow. In birds that learn their songs, dispersal can affect the ability of male birds to share songs in song dialects and may influence mate attraction. We used Inductively Coupled Plasma Mass Spectrometry (ICP-MS) trace element analysis on the body feathers of birds to assess dispersal among four song dialects. We found that (1) most males had a feather element profile typical of only one dialect location; (2) males singing non-local (‘foreign’) dialects in a focal population often learned their foreign songs outside the dialect; and (3) females often dispersed among dialects. We estimated 5% dispersal per year by yearling males between the site of moulting and breeding. Our estimate is consistent with genetic estimates of widespread gene flow between dialects in this subspecies of the white-crowned sparrow. PubDate: 2017-07-13T00:00:00Z
Authors:Ladislav Naďo; Renáta Chromá Peter Kaňuch Abstract: Source: Page Count 23Social groups of bats that operate under fission–fusion dynamics tend to establish and maintain non-random associations. We examined the social and genetic structure of the Leisler’s bat (Nyctalus leisleri), a species that is typical of tree-dwelling and long-distance migratory species in Europe. We used long-term co-occurrence data (capture-recapture sampling of roosting individuals) in combination with individual genetic relatedness (inferred from a set of microsatellite markers) to assess relationships between structural, temporal and genetic properties of roosting groups. Our results showed that social structure in groups of roosting Leisler’s bat was not random. Social clusters revealed by network analysis were almost identical to demographic cohorts, which indicates that Leisler’s bats are able to maintain social bonds only over a single season. After the period of active maternal care, roosting groups became smaller with a significantly higher level of genetic relatedness among adult females in contrast to the pregnancy and lactation stages. This provides some evidence that temporal social associations may be positively correlated with genetic relatedness. Low recapture rates of bats across seasons in light of natal philopatry indicates a shorter life span of individuals likely due to high mortality during long distance migratory movements. This probably has the most significant effect on the social system of this species. PubDate: 2017-06-28T00:00:00Z
Authors:Charlotte Canteloup; Isis Poitrasson, James R. Anderson, Nicolas Poulin Hélène Meunier Abstract: The complex social environments of primates create opportunities for engaging in tactical deception, especially for subordinate individuals. We analysed the behaviour of subordinate Tonkean macaques with dominant conspecifics in an experimental food competition context. The subordinate macaque could see two pieces of food in a test area, but only one piece was visible to the dominant. Both individuals were released into the test area at the same time or with the subordinate given a short head start on the dominant. Here, based on video analysis of the subordinates’ behaviours, we describe and classify functionally deceptive behaviours displayed by subordinates, and report factors that influenced these behaviours. Subordinates used several types of tactical deception, including concealment and distraction, especially when paired with competitors of much higher social rank, and they obtained the hidden food more frequently when they used a combination of tactics rather than only one. PubDate: 2017-06-26T00:00:00Z
Authors:Adriano Bruno Chaves Molina; Montserrat Colell Mimó Abstract: Source: Page Count 22In this study we tested an adult female Martin’s spot-nosed monkey in several configurations of the string-pulling paradigm, including six different discrimination problems of patterned strings. Our subject solved almost all of the problems presented. Although she seemed to have a spatial preference in the most complex tasks, she maintained a high success rate in almost all of them. She also showed goal-directed behaviour that was not strictly based on visual feedback. Although more research is needed to understand better the subject’s performance, we conclude that she showed clear signs of understanding physical continuity, and some degree of understanding of connectedness and causal relationships. PubDate: 2017-06-23T00:00:00Z
Authors:Eilea R. Knotts Abstract: Source: Page Count 24Recognizing which phenotypic traits are predictors for habitat choice can have important implications for understanding population dynamics. This study determined whether body size, sex, activity level, or origin habitat affected the preference of the fiddler crab, Uca pugilator, in selecting either a marsh or open mudflat, two habitats differing in risk level and food availability. Combining field and laboratory experiments, this study indicated a significant difference in body size and activity level of crabs between habitats. Further investigation of phenotypic dependency on habitat preference resulted in interactions between origin habitat and carapace width and activity level. When split by origin habitat, habitat preference for the open mudflat was predicted by body size for crabs originating from the open mudflat and by activity level for the crabs originating from the Spartina marsh. These results suggest that, for U. pugilator, body size plays a large role in the preference for exposed habitat. PubDate: 2017-06-23T00:00:00Z
Authors:Tadashi Miyashita; Minoru Kasada Akio Tanikawa Abstract: Source: Page Count 10Spiders in the subfamily Cyrtarachninae, including bolas spiders, are moth specialists, and it has been suggested that these spiders initiate web-weaving under high humidity. Here we used Pasilobus hupingensis to experimentally test whether Cyrtarachninae spiders build webs exclusively under high humidity. The results showed that humidity, as well as temperature and prey feeding history, affected web-building probability, but humidity had a much stronger effect. Moreover, spiders never constructed webs at under PubDate: 2017-05-31T00:00:00Z
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