Evidence For Social Structure Research Articles

Husbandry practices as evidence for social structure and dominance systems in rural society during the Central Middle Ages (Provence, Southern France; 10th-12th centuries AD)

This paper critically revisits three Provençal seigneurial domains from the 10th-12th centuries AD through new zooarchaeological and archaeological data as well as through the work of historians. The contexts studied correspond to four seigneurial, two military and one peasant settlements. The results of the zooarchaeological analyses highlight the predominance of pigs in the elite contexts and that of caprines among the peasants. The data from these different social groups show several other distinctions: herd management (e.g., lamb consumption favoured by the elites), skeletal distributions of caprines (e.g., variable frequency of heads) and pigs (e.g., under-representation of hams in humble contexts). This paper aims to shed light on the social structure and dominance systems between lords and peasants during the beginning of the feudal period, The discussion is mainly oriented towards pig and caprines husbandry which yields new insights into peasant daily-life, peasantry rights and obligations towards lords, territorial management, and the role of peasant communities in the economic development of the Provençal aristocracy. The analysis reveals the mechanisms of dominance and oppression on which the feudal political system was based.

Social preferences and network structure in a population of reef manta rays

Understanding how individual behavior shapes the structure and ecology of populations is key to species conservation and management. Like many elasmobranchs, manta rays are highly mobile and wide-ranging species threatened by anthropogenic impacts. In shallow water environments, these pelagic rays often form groups and perform several apparently socially mediated behaviors. Group structures may result from active choices of individual rays to interact or passive processes. Social behavior is known to affect spatial ecology in other elasmobranchs, but this is the first study providing quantitative evidence for structured social relationships in manta rays. To construct social networks, we collected data from more than 500 groups of reef manta rays (Mobula alfredi) over 5 years in the Raja Ampat Regency of West Papua. We used generalized affiliation indices to isolate social preferences from non-social associations, the first study on elasmobranchs to use this method. Longer lasting social preferences were detected mostly between female rays. We detected assortment of social relations by phenotype and variation in social strategies, with the overall social network divided into two main communities. Overall network structure was characteristic of a dynamic fission-fusion society, with differentiated relationships linked to strong fidelity to cleaning station sites. Our results suggest that fine-scale conservation measures will be useful in protecting social groups of M. alfredi in their natural habitats and that a more complete understanding of the social nature of manta rays will help predict population responses to anthropogenic pressures, such as increasing disturbance from dive tourism. In social animals, relationships between individuals have important implications for species conservation. Like many other sharks and rays, manta rays are threatened species, and little is known about their natural behavior or how their populations are structured. This study provides evidence of social structure in a wild, free-ranging population of reef manta rays. We show for the first time that individual manta rays have preferred relationships with others that are maintained over time, and structured societies. This study extends our knowledge of elasmobranch ecology and population structuring. Results suggest that understanding social relationships in manta rays will be important in protecting populations from human impacts and developing sustainable, localized conservation and management initiatives.

Parturition site selection in moose (Alces alces): evidence for social structure

Female natal philopatry has often been implicated as an important factor in moose ( Alces alces ) home range formation, with many populations showing behavioral evidence of sympatric home ranges among related individuals. However, previous genetic studies have failed to detect genetic subpopulation structure, leading to questions as to whether philopatry is a significant factor contributing to intra- and inter-population genetic structure. Here, we examine calving location data from radiomarked individuals ( n = 110) collected in 2 separate populations in Berners Bay and Gustavus, Alaska, to examine the extent to which genetic structure originating from philopatry is evident at fine spatial scales. When populations were combined, their overall relatedness correlogram was significant ( P < 0.001), with mean r = 0.079 between 0 km and 1.5 km ( P = 0.079). Additionally, 13% of the population shows significantly positive relatedness to their 4 nearest neighbors, with an overall average r = 0.19 of those focal individuals to their neighbors. We suggest that habitat structure, especially linear habitats (i.e., river valleys), or habitat bounded with barriers to dispersal, may be a factor in promoting the development of this structure. This study presents the 1st known evidence for fine-scale social genetic structure in moose and natal philopatry to calving locations in moose. In the context of natal philopatry within cervids, these findings identify several cervid-wide commonalities.

Caste formation in larval Himasthla elongata (Trematoda) infecting common periwinkles Littorina littorea

Reproductive division of labour is well-known in several animal groups but the ecological factors driving the evolution of such social organization are still being discussed. Recent studies have discovered social organization in four marine species of trematode parasites having two distinct castes specialized for reproduction and defence of the clonal intra-molluscan larval colony, respectively. Here, we provide novel evidence for social structure also in colonies of the trematode Himasthla elongata infecting the common periwinkle Littorina littorea. We found two types of rediae, the parthenogenetic larval offspring of the parasite: small non-reproductive rediae and considerably larger reproductive rediae. Both redial types possessed a digestive system, collar and posterior appendages and, hence, aside from dimensions, were morphologically similar. However, in vitro experiments showed that non-reproductive morphs attacked heterospecific competing parasites at a higher rate (2–3 fold) than reproductive morphs did. No within-colony antagonism was observed. In contrast to a previous study on a congeneric trematode species, our findings suggest a relatively weak caste formation in H. elongata, possibly resulting from a corresponding weaker level of interspecific competition.

Virtual Cities

This project employs a student-generated geographic database that links the Commedia to relevant passages from Dino Compagni’s Cronica and visual records at appropriate locations in Florence. The database records evidence for social structure, physical infrastructure, and historic events, as well as the civic/religious ritual of the city, in order to consider the broader meanings of the built environment. This database is displayed on satellite images of the city using the open-source SIMILE widget Exhibit. The student can then analyze this evidence and consider how Dante constructed his allegorical societies, infernal, purgative, and paradisiacal, from the life of his contemporary Florence. It is suggested that this permits more rapid immersion into the dynamic of the poem and enables more effectively focused student research.

Multiple Captures of White-Footed Mice (Peromyscus Leucopus): Evidence for Social Structure?

Multiple captures (34 double, 6 triple) in standard Sherman live traps accounted for 6.3% of 1355 captures of Peromyscus leucopus (white-footed mice) in forested habitat in southern Illinois, from Oct. 2004 through Oct. 2005. There was a significant positive relationship between both the number and the proportion of multiple captures and estimated monthly population size. Multiple captures were all intraspecific and occurred significantly more often from Nov. through Mar. when animals were not reproductively active, but this was confounded by seasonal changes in abundance. Age/gender distribution of animals in double captures did not differ from that expected from random pairing. We suggest that sociality and synchronous entry of two white-footed mice into traps were the primary determinants of double captures; sensitivity of traps may have been the primary factor in triple captures.