Spatiotemporal dynamics of the social structure of Indo-Pacific humpback dolphins(Sousa chinensis)in Xiamen waters from 2007 to 2019

As highly social animals,Indo-Pacific humpback dolphins(Sousa chinensis)exhibit community differentiation.Nevertheless,our understanding of the external and internal factors influencing these dynamics,as well as their spatiotemporal variations,is still limited.In the present study,variations in the social structure of an endangered Indo-Pacific humpback dolphin population in Xiamen Bay,China,were monitored over two distinct periods(2007–2010 and 2017–2019)to analyze the effects of habitat utilization and the composition of individuals within the population.In both periods,the population demonstrated a strikingly similar pattern of social differentiation,characterized by the division of individuals into two main clusters and one small cluster.Spatially,the two primary clusters occupied the eastern and western waters,respectively,although the core distribution area of the eastern cluster shifted further eastward between the two periods.Despite this distribution shift,the temporal stability of the social structure and inter-associations within the eastern cluster remained unaffected.A subset of 16individuals observed in both periods,comprising 51.6%and 43.2%of the population in each respective period,emerged as a foundational element of the social structure and may be responsible for sustaining social structure stability,especially during the 2007–2010 period.These observations suggest that the composition of dominant individuals,an internal factor,had a more substantial influence on the formation of the social network than changes in habitat use,an external factor.Consequently,the study proposes distinct conservation measures tailored to each of the two main clusters.

Social Capital Approach for Explaining Ethnic Conflicts Within a Liberal Society

This paper examines the reasons why many ethnic movements surge in liberal societies-even though these societies are supposed to enable the coexistence of different types of people-and whether it is possible to resolve ethnic conflicts within these societies. Social capital, such as mutual trust, diffusion of information, and social support is used in this discussion, as successful coexistence in a liberal society is only possible when social capital is adequately provided to all people. Since social capital is generated from social networks, minorities want networks that may increase the likelihood that they will attain an adequate level of social capital. They attempt to build such networks by making their cultural symbols recognized by others. Confrontations that result from this kind of movement often cause ethnic conflicts. The key to resolution, then, is whether a broad network can be built, to which all different people are satisfactorily connected. As a result, this paper shows that even though such a resolution is theoretically possible, in reality there are three serious obstacles： （1） people tend to be driven by strong emotions; （2） people cannot accurately estimate the extent of suffering and/or the level of required support; and （3） minorities＇ primary networks are too solidified to be connected suitably to the wider network. These findings will contribute to the further argument of what conditions should be met in order to take feasible measures to resolve ethnic conflicts within a liberal society.