The fate of defeated alpha male chimpanzees in relation to their social networks

Usurpation of alpha status by males is a relatively rare event among wild chimpanzees in the Mahale Mountains National Park, western Tanzania, where long-term field studies have been carried out since 1965. Here we report three such cases and compare the fate of those defeated alpha males. The formation of effective alliances with other adult males is considered to be crucial in determining what will happen to the defeated alpha male in the rank order after the loss of his status.     

Field assessment of B-2 as a new molluscicide for the control of Oncomelania nosophora

Sodium 2,5-dichloro-4-bromophenol named B-2 was evaluated for application in the field as a molluscicde against Oncomelania nosophora. A dosage of 10 g/m2 as 25% liquid form or 25 g/m2 as 10% granular form of B-2 was suggested as a standard dose for the control of O. nosophora. The residual concentration of B-2 in the soil after application was observed to decrease more rapidly than did that of NaPCP. The residual level of B-2 in the rice grains harvested from the paddy field in which the chemical was applied at most 4 times during the planting season did not exceed 0.03 ppm.