Facultative social parasitism in the allodapine bee Macrogalea berentyensis

Previous research on social parasitism has largely ignored allodapine social parasites, which is surprising given the huge potential of these bees to provide a better understanding of social parasitism. Macrogalea berentyensis, a species that was previously suggested to be a social parasite, was collected in nests of M. ellioti, and also in nests consisting of only M. berentyensis. These f＇mdings, along with morphological and phylogenetic evidence, show that this species is a facultative social parasite. In the independently living M. berentyensis nests, brood were present that had been reared to an advanced stage, suggesting that： （i） these parasites may be effective at foraging and caring for their brood; or （ii） these nests may be colonies where all the hosts had died, and these parasites had yet to disperse. Macrogalea berentyensis is the closest relative of the facultative social parasite, M. antanosy, and both these species represent the most recent evolutionary origin of social parasitism within the allodapines. Further behavioral research on both these parasitic species would therefore have important implications for the understanding of the evolution of social parasitism.     

Schistosomiasis in Brazil: Does social development suffice?

Up to 15 years ago, when asked to identify the major public health problems of Brazil, there would be no hesitation in naming infant diarrhoea, Chagas disease and Schistosoma mansoni. While most field workers have now eliminated schistosomiasis from the list, now certainly headed by malaria, in academic and bureaucratic circles the old priorities are still maintained.     

Genomics research in the UK—the social science agenda

Abstract

We sketch the development of UK genetics and genomics research, and emphasize the UK's key role in the international genetics and genomics research community. We highlight in particular the part played by the UK's Research Councils and other funders. With the move from genomics to post-genomics research, the field is diversifying, and interdisciplinarity becomes increasingly important, as traditional disciplinary boundaries become blurred, or break down, in the face of newly emerging sciences. We consider the changing nature of health and ill health in the developed and developing world, and questions about the complex nature of the relationships between genes and the environment, and their future implications for human health and human populations. We describe the ESRC's activities, stressing the importance of both the social, ethical and legal issues raised by these emerging disciplines, and of public engagement. Finally, we link the data handling and analysis issues raised by these emerging sciences, with other new research areas, in particular the UK's e-Science programme.     

Is lipsmacking an indicator of social status in baboons?

Lipsmacking is performed by many Old World monkey species, and some studies of baboons and macaques suggest that lipsmacking may be associated with social status. We studied 60 adult anubis baboons (Papio cynocephalus anubis) for 18 months, measured social status and the rate of lipsmacking, and used these data to test the hypothesis that lipsmacking is related to social status. Our results indicate that social status and lipsmacking were not significantly correlated for either males or females. Analysis of lipsmacking in relation to social class (high vs. low) showed no significant difference between status classes for either sex. Lipsmacking was, however, found to be positively associated with affinitive behaviors. These results suggest that baboon lipsmacking provides positive social communication independently of social status.     

Testing the social dog hypothesis: Are dogs also more skilled than chimpanzees in non-communicative social tasks?

Relative to non-human primates, domestic dogs possess a number of social skills that seem exceptional—particularly in solving problems involving cooperation and communication with humans. However, the degree to which dogs’ unusual skills are contextually specialized is still unclear. Here, we presented dogs with a social problem that did not require them to use cooperative-communicative cues and compared their performance to that of chimpanzees to assess the extent of dogs’ capabilities relative to those of non-human primates. We tested the abilities of dogs and chimpanzees to inhibit previously learned responses by using a social and a non-social version of a reversal learning task. In contrast to previous findings in cooperative-communicative social tasks, dogs were not more skilled on the social task than the non-social task, while chimpanzees were significantly better in the social paradigm. Chimpanzees were able to inhibit their prior learning better and more quickly in the social paradigm than they were in the non-social paradigm, while dogs took more time to inhibit what they had learned in both versions of the task. These results suggest that the dogs’ sophisticated social skills in using human social cues may be relatively specialized as a result of domestication.     

Could asynchrony in activity between the sexes cause intersexual social segregation in ruminants?

In many sexually dimorphic mammal species, the sexes live outside the mating season in separate social groups (''social segregation''). Social segregation occurs in a wide range of environmental conditions, but its cause in unknown. I suggest that social segregation is caused by a lower level of activity synchrony between individuals in mixed-sex groups than in single-sex groups, owing to sex differences in activity rhythm. As a consequence, mixed-sex groups are more likely to break up than single-sex groups, resulting in a predominance of single-sex groups at equilibrium. To test this hypothesis in red deer (Cervus elaphus L.), I developed an index of activity synchronization and showed that deer in mixed-sex groups were significantly less synchronized in their activity than deer in single-sex groups. Thus, low intersexual synchrony in activity can lead to social segregation. However, a lower level of intrasexual (female-female and male-male) activity synchrony within mixed-sex than within single-sex groups implies that additional factors (other than sex differences in foraging rhythm) contribute to the higher degree of instability of mixed-sex groups.     

Does genetic diversity hinder parasite evolution in social insect colonies?

Polyandry is often difficult to explain because benefits of the behaviour have proved elusive. In social insects, polyandry increases the genetic diversity of workers within a colony and this has been suggested to improve the resistance of the colony to disease. Here we examine the possible impact of host genetic diversity on parasite evolution by carrying out serial passages of a virulent fungal pathogen through leaf-cutting ant workers of known genotypes. Parasite virulence increased over the nine-generation span of the experiment while spore production decreased. The effect of host relatedness upon virulence appeared limited. However, parasites cycled through more genetically diverse hosts were more likely to go extinct during the experiment and parasites cycled through more genetically similar hosts had greater spore production. These results indicate that host genetic diversity may indeed hinder the ability of parasites to adapt while cycling within social insect colonies.     

What determines the growth of individual castes in social trematodes?

Phenotypic diversification among colony members often leads to formation of physical castes which are morphologically specialised for particular tasks within the colony. The relative abundance of these castes and their body sizes represent two key aspects of the demography of a colony that may reflect the colony’s needs and conditions, and ultimately influence its survival and reproductive success. In a recently discovered social trematode, Philophthalmus sp., which exhibits a reproductive division of labour, the role of competition and colony composition in shaping reproductive success and behaviour of colony members has been documented. As body size variation within physical castes often influences colony efficiency, we investigated how the growth of reproductive and non-reproductive morphs of Philophthalmus sp. responds to competitive pressure, and to other attributes of colony demography such as colony size and composition. Our survey of a natural population and in vitro experiments demonstrate that the growth of reproductive colony members reflects the interaction between colony composition and the presence of a competitor, while the non-reproductive members simply grow larger in the presence of the intra-host competitor, Maritrema novaezealandensis. Furthermore, the close association between the volume and reproductive capacity of the reproductive members corroborates an adaptive value of colony member size in determining the fitness of the trematode colony as a whole. The present study is the first to demonstrate a fitness consequence, and identify the determinants, of the growth of colony members in social trematodes.     

The problem and promise of scale in multilayer animal social networks

Scale remains a foundational concept in ecology.Spatial scale,for instance,has become a central consideration in the way we understand landscape ecology and animal space use.Meanwhile,scale-dependent social processes can range from fine scale interactions to co-occurrence and overlapping home ranges.Furthermore,sociality can vary within and across seasons.Multilayer networks promise the explicit integration of the social,spatial,and temporal contexts.Given the complex interplay of sociality and animal space use in heterogeneous landscapes,there remains an important gap in our understanding of the influence of scale on animal social networks.Using an empirical case study,we discuss ways of considering social,spatial,and temporal scale in the context of multilayer caribou social networks.Effective integration of social and spatial processes,including biologically meaningful scales,within the context of animal social networks is an emerging area of research.We incorporate perspectives that link the social environment to spatial processes across scales in a multilayer context.     

Are olfactory cues involved in nest recognition in two social species of estrildid finches?

Reliably recognizing their own nest provides parents with a necessary skill to invest time and resources efficiently in raising their offspring and thereby maximising their own reproductive success. Studies investigating nest recognition in adult birds have focused mainly on visual cues of the nest or the nest site and acoustic cues of the nestlings. To determine whether adult songbirds also use olfaction for nest recognition, we investigated the use of olfactory nest cues for two estrildid finch species, zebra finches (Taeniopygia guttata) and Bengalese finches (Lonchura striata var. domestica) during the nestling and fledgling phase of their offspring. We found similar behavioural responses to nest odours in both songbird species. Females preferred the odour of their own nest over a control and avoided the foreign conspecific nest scent over a control during the nestling phase of their offspring, but when given the own odour and the foreign conspecific odour simultaneously we did not find a preference for the own nest odour. Males of both species did not show any preferences at all. The behavioural reaction to any nest odour decreased after fledging of the offspring. Our results show that only females show a behavioural response to olfactory nest cues, indicating that the use of olfactory cues for nest recognition seems to be sex-specific and dependent on the developmental stage of the offspring. Although estrildid finches are known to use visual and acoustic cues for nest recognition, the similar behavioural pattern of both species indicates that at least females gain additional information by olfactory nest cues during the nestling phase of their offspring. Thus olfactory cues might be important in general, even in situations in which visual and acoustic cues are known to be sufficient.     

Phenotypic similarity in sympatric crow species: Evidence of social convergence?

Crows, rooks, and ravens (Corvus spp.) display marked morphological and voice similarities that have been hypothesized to stem from competitive interactions, as a case of nonaposematic mimicry. Here, I test predictions of the mimicry hypothesis at the macrovolutionary scale, examining whether species morphological and acoustic traits covary with those of coexisting congeners, and whether phenotypic similarity has facilitated the coexistence of related species after secondary contact. Body size and the temporal patterns of the commonest call display high levels of similarity among sympatric species, even after controlling for the effect of shared climate and habitat, and phylogenetic constraints in the production of variation. When sister species differed in these acoustic and morphological traits, their transition to secondary sympatry was delayed relative to those with more similar traits. No similarity was found in the sexual call of crows, suggesting that convergence occurs only when function does not favour maintenance of species‐specific traits. Crow similarities in morphological and acoustic features may therefore be associated with coevolving interactions with congeners, in line with a broad array of studies documenting convergence among species that interact aggressively or forage communally.     

When does play panting occur during social play in wild chimpanzees?

To clarify the social functions of play panting in chimpanzees, I investigated when they emitted play panting in social play and how the interactions were affected by the occurrence of play panting. The subjects were the M-group chimpanzees living in Mahale, Tanzania. The following observations were made: (1) chimpanzees emitted play panting when they were tickled or chased but rarely did so when they tickled or chased others. Chimpanzee play panting does not have the function of a play signal communicating that these aggressive actions are performed not as aggression but as play. (2) Chimpanzees emitted play panting more often when they received aggressive actions that supposedly elicited higher arousal. (3) A chimpanzee tended to continue to perform aggressive actions when the target emitted play panting. Play panting activates the interaction of social play by encouraging the performer to continue tickling or chasing. These results can be summarized as showing that chimpanzee play panting serves as positive feedback to the play partner for continuing somewhat fragile interactions, which may contain the risk of excessive arousal and the risk of confusing defensive actions by the target of the aggressive actions with real efforts to escape the situation.     

Chromosomal variation in social voles: a Robertsonian fusion in Günther’s vole

The study reports on chromosomes in several populations of social voles from south-eastern Europe and the Middle East. The standard karyotypes of individuals of Microtus hartingi and Microtus guentheri originating from both south-eastern Europe and Asia Minor comprised 54 mostly acrocentric chromosomes. However, variation between populations was found in the amount and distribution of C-heterochromatin in certain autosomes and the sex chromosomes. Furthermore, a specific pattern of argyrophilic nucleolar organizer region distribution was recorded in different geographic populations. In a population from Asia Minor, a heterozygous centric fusion of two autosomes was found. The G-banded karyotypes of M. guentheri and Microtus socialis were compared, and tandem fusions of autosomes were suggested as possible mechanism of the divergence. The karyotypes of the nine currently recognized species of social voles are reviewed, and implications of chromosomal data for systematics are evaluated.     

Gender differences in sexual jealousy: Adaptionist or social learning explanation?

It has often been speculated, and some evidence suggests, that men and women differ in the elicitation of jealousy: Men appear to be more likely than women to become upset over threats to sexual exclusivity; whereas women are more likely than men to react negatively to potential loss of partner time and attention. Both adaptionist and traditional social learning theories have been used to explain these apparent gender differences. In the present article we outline both explanations and review the relevant psychological literature on gender differences in the elicitation of jealousy. We propose that the difference in men's and women's psychological mechanisms for elicitation of jealousy is best characterized (at least in this culture) as a greater sensitivity among men to cues indicative of possible sexual infidelity rather than greater emotional upset in response to the occurence of extradyadic sex on the part of one's mate. We also provide data testing a traditional social learning explanation for the elicitation of jealousy. Results of a survey administered to college students (N = 223) demonstrate the subtle nature of gender differences in the elicitation of jealousy within this culture. Men and women were most likely to differ (in the hypothesized directions) when items pertained to concern over a partner's potential extradyadic sex rather than to reactions to sexual infidelity that is suspected to have already occurred. Although men reported placing more value on sexual activity within dating relationships and women reported placing more value on emotional intimacy, these ratings of relationship rewards did not explain the gender differences in reported jealousy. Results failed to support a traditional social learning explanation of jealousy and are discussed with regard to evolutionary theory and directions for future research.