Do males bond? A study of male-male relationships in Nicobar long-tailed macaques Macaca fascicularis umbrosus

Due to their unique properties, carbon nanotubes (CNTs) are being widely explored for industrial and medicalapplications. This has necessitated a thorough assessment of the effect of CNTs on human and animalphysiology and health. Impact of CNTs on epithelial tight junctions has not been evaluated in the context oftheir toxic effects in many biological systems. In the present study, we examined the effect of acid functionalized single-walled carbon nanotubes (AF-SWCNTs) on the function and expression of two tight junctionproteins (ZO-1 and occludin) in the Madin-Darby canine kidney (MDCK) cell line. Treatment of MDCK cellswith AF-SWCNT resulted in a downregulation of tight junction proteins, decreased trans-epithelial electricalresistance (TER), increased paracellular permeability, and disruption of tight junctions. Taken together, ourdata demonstrate that AF-SWCNT disrupts tight junction barrier by downregulating tight junction proteins inMDCK epithelial cells.

Diet-dependent habitat shifts at different life stages of two sympatric primate species

A shift or expansion of the realized niche at different life stages is often ignored while implementing conservation actions.We tested whether habitat extent and associations at different life stages of two sympatric primate species belonging to thesame taxonomic family vary with respect to their dietary requirements. We expected the groups and solitary males of afrugivorous species to have a smaller extent of suitable habitat than those of a folivorous species. We used MaxEntmodelling to create habitat suitability maps using occurrence records and high-resolution remotely sensed environmentallayers for groups and solitary males of highly frugivorous lion-tailed macaques and highly folivorous Nilgiri langurs in theWestern Ghats, India. We found that the Nilgiri langur groups and lion-tailed macaque groups occupied a similar extent inour study area. However, due to weaker restrictions, the Nilgiri langur groups were observed to inhabit a broader variety ofhabitats than the lion-tailed macaque groups. Solitary males of both the lion-tailed macaque and Nilgiri langur migratethroughout the landscape, with only a 50% habitat overlap with their respective groups. We propose that a species’ dietaryrequirements have differential effects on habitat use, especially during dispersal, at the solitary stage in males.

Dominance hierarchy and social grooming in female lion-tailed macaques (Macaca silenus) in the Western Ghats, India.

This article reports the structure of dominance and its relationship with social grooming in wild lion-tailed macaque females. The strength of dominance hierarchy was 0.79 on a scale of 0 to 1 indicating a moderate linearity in the ranking system. Dominance scores were converted into an ordinal as well as an interval scale. Grooming scores were also converted into interval scales using standard scores. Grooming received and grooming given correlated positively and negatively respectively with dominance ranks indicating that high ranking females received more and gave less grooming. Grooming was also positively related to encounter rates for dyads of females. More grooming among adjacent ranks, and grooming being more reciprocal, occurred only in the case of dominant females. The grooming patterns, therefore, appeared to be more of despotic than egalitarian nature. While ranking macaques into different Grades of social systems ranging from despotic to egalitarian, Thierry (2004) has placed lion-tailed macaques in Grade 3 corresponding to the 'relaxed' social system. Our results indicate that the grooming and dominance relationships in this species are more despotic, and hence, the Grade for this species requires to be shifted toward 2 or 1.

Hierarchy, kinship and social interaction among Japanese monkeys (Macaca fuscata).

The study reports the relationship between hierarchy, genetic relatedness and social interaction in captive Japanese macaques. Grooming and proximity were found to be positively related to both dominance rank and degrees of relatedness. Ranks also positively correlated with threats while no relationship was observed between genetic relationships and agonistic interactions. The removal of a-male tightened the male hierarchy while the female hierarchy became relatively loose. Affiliative behaviour became more correlated with ranks than degrees of genetic relatedness. In the absence of α-male, the next dominant male avoided involvement in either agonistic or afliliative interactions with reintroduced animals and group females.