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:Javier I. Borráz-León; Ana Lilia Cerda-Molina Lilian Mayagoitia-Novales Abstract: Source: Page Count 15An individual’s body odour is a characteristic that is used to obtain information about conspecifics. However, to our knowledge the role of body odour and the degree of facial symmetry on testosterone changes among men as indicators of possible rivals has not been investigated yet. A group of 113 men were photographed to obtain their degree of facial symmetry, i.e., the small random deviations in facial bilateral traits. They smelled and assessed the odour of men with different grades of facial symmetry, and donated two saliva samples (pre- and post-stimulus sample) to measure the change in their testosterone levels. We found that testosterone levels decreased in symmetrical men who perceived the odour of asymmetrical men. Our results suggest that men could perceive characteristics in other men that are highly valued by women through odour to identify possible rivals, and that the observed decrease in testosterone levels could be related to an inhibition of competitive behaviours. PubDate: 2017-06-08T00:00:00Z
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
Authors:Vladimir S. Gromov Abstract: Source: Page Count 41There are two types of complex social units — aggregations and family groups — in rodent populations, with an essential difference in their social organization. The impact of ecological factors on the evolution of sociality in rodents (the transition from solitary towards family-group lifestyle) is still unclear. The inter-specific comparative analysis based on quantification of social traits related to the spatial-and-ethological population structure and cooperation allows author to propose a new conceptual approach to the assessment of differences between the species under consideration in terms of the evolution of sociality. A new conceptual model of the evolution of sociality in rodents should incorporate ecological conditions and social factors, including cooperation, operating as a complex of selective forces promoting formation of family groups. PubDate: 2017-05-30T00:00:00Z
Authors:K.P. Little; L. Al-Shaer M. Itzkowitz Abstract: Source: Page Count 25For species in which individuals spend at least some time in groups, dominance relationships and various social cues are often important for mate assessment and choice. For pair bonding species, social experiences may affect reproductive decisions in both sexes. We tested whether prior experience in a mixed-sex group and having a higher dominance status coincides with faster pair formation or spawning in a monogamous fish. Individuals having prior experience in mixed-sex groups paired with a novel fish more frequently than fish from same-sex groups. Fish in mixed-sex groups performed more bites and lateral displays. Although spawning occurred infrequently across pairs, dominant fish from mixed-sex groups spawned more than dominant fish from same-sex groups. Otherwise, there were no clear behavioural relationships between treatment group and subsequent pair formation or spawning, nor were behaviours of the paired fishes related to their prior treatment group. We do not know how mixed-sex social experience may have affected the physiology of those individuals, although our results support a reproductive priming effect. PubDate: 2017-05-29T00:00:00Z
Authors:Eduardo C. Quintana; Conrado A.B. Galdino Abstract: Source: Page Count 16A reduction of territory owners’ aggression towards their neighbours in relation to the intrusion of strangers characterises the dear enemy phenomenon. Supposedly, the disparity in aggression levels of territory owners is due to a higher threat imposed by strangers compared to the threat imposed by neighbours. To evaluate the occurrence of the phenomenon in males of the small-sized lizard Eurolophosaurus nanuzae we performed a field manipulative study. We considered three models to run intrusions in males’ territories: neighbour, tailed stranger (unfamiliar) and tailless stranger intruders. Our results lend support to the presence of dear enemy for this species as residents acted more aggressively towards strangers than to neighbours. In addition, the information we provide supports the relative threat hypothesis as territory owners were more aggressive towards tailed stranger intruders than to tailless stranger intruders. In this sense, tail condition can represent a trait that signals the ‘resource holding power’ (RHP) of a lizard. Therefore, we show that beyond neighbourhood recognition, residents are able to evaluate the potential threat of stranger intruders in general, thereby extending the evolutionary gains of the dear enemy by saving energy even in the context they are expected to acts with higher costs. PubDate: 2017-05-26T00:00:00Z
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