In this study troop of chacma baboons (Papio cynocephalus ursinus) at Mkuzi Game Reserve, Zululand, South-Africa, it is suggested that risk of predation and competition over safe spatial position had more importance and effect on female behaviour than did competition for food. Only 6.4% of all agonistic events were over food patches and no significant correlation was found between a female's dominance rank and proportion of time spent feeding, feeding bout length or diet composition. Parameters of reproductive success, such as inter-birth intervals and infant mortality were not correlated with female dominance rank. Female mortality, however, was related to dominance rank and all of the five females who disappeared during the study were low-ranking. Four of the five females disappeared after troop fission. There is circumstantial evidence supporting the suggestion that predation by leopards is the main cause of mortality of females at Mkuzi. High levels of female aggression were recorded, with almost no occurrences of support coalitions. Most of the aggression took place among similar ranking females, or was directed by the top ranking toward the lowest ranking females. Most of the female-to-female agonistic encounters were in a social context, and more than half were over a spatial position next to other adult troop members. Aggression among females increased after troop fission. It is suggested that the higher-ranking females may be better protected from predation, through access to more central spatial positions in the troop. Indeed, a positive correlation was found between a female's dominance rank and the time spent next to other adult troop members. It may be that avoiding food competition by keeping larger distances from others, while foraging, was translated in lower ranking females to a cost of higher predation risk.
The status of marine turtles in Angola, West Africa, is poorly known, and
therefore during 2000–2006 a combination of both dedicated and
opportunistic beach and at-sea turtle surveys were carried out, and interviews
conducted with fishing communities and at markets. Green Chelonia mydas, olive ridley Lepidochelys olivacea, leatherback Dermochelys coriacea and loggerhead turtles Caretta caretta were recorded, and nesting of the
first three species confirmed during September–March (peaking
November–December). Green turtles nested mainly in the south,
leatherback turtles in north and central Angola, and olive ridley turtle nesting
was widespread. Olive ridley turtle nest density at Palmeirinhas averaged 32
nests km−1. At-sea surveys produced 298 turtle records,
with peak occurrence during August. Significant anthropogenic-related mortality
(including exploitation of meat and eggs and fishing bycatch) was recorded, in
addition to natural predation and other threats. Maintenance of the long-term
sustainability of these turtle populations should focus on the involvement of
fishing communities and increasing awareness throughout Angola.
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