The Influence of Life History Milestones and Association Networks on Crop-Raiding Behavior in Male African Elephants

Factors that influence learning and the spread of behavior in wild animal populations are important for understanding species responses to changing environments and for species conservation. In populations of wildlife species that come into conflict with humans by raiding cultivated crops, simple models of exposure of individual animals to crops do not entirely explain the prevalence of crop raiding behavior. We investigated the influence of life history milestones using age and association patterns on the probability of being a crop raider among wild free ranging male African elephants; we focused on males because female elephants are not known to raid crops in our study population. We examined several features of an elephant association network; network density, community structure and association based on age similarity since they are known to influence the spread of behaviors in a population. We found that older males were more likely to be raiders than younger males, that males were more likely to be raiders when their closest associates were also raiders, and that males were more likely to be raiders when their second closest associates were raiders older than them. The male association network had sparse associations, a tendency for individuals similar in age and raiding status to associate, and a strong community structure. However, raiders were randomly distributed between communities. These features of the elephant association network may limit the spread of raiding behavior and likely determine the prevalence of raiding behavior in elephant populations. Our results suggest that social learning has a major influence on the acquisition of raiding behavior in younger males whereas life history factors are important drivers of raiding behavior in older males. Further, both life-history and network patterns may influence the acquisition and spread of complex behaviors in animal populations and provide insight on managing human-wildlife conflict

Discovery of Two Additional Prosimian Primate Families (Omomyidae, Lorisidae) in the African Oligocene

Three new specimens reported here are referable to the Omomyidae and Lorisidae, and represent only the second and third prosimian primates found in the Oligocene rocks of the Fayum, Egypt. The Fayum omomyid extends the range of the Omomyidae into Africa, while the Fayum lorisid is the oldest record of the Lorisidae world-wide. Afrotarsius established ?Tarsiidae as a third prosimian family present in Oligocene rocks of the Fayum region of Egypt (Simons & Bown, 1985). These new occurrences significantly reorient paleogeographic study of primate origins. In a fauna famed for the presence of about a thousand specimens of early Anthropoidea-viz. Apidium, Parapithecus, Qatrania, Propliopithecus, Oligopithecus, and Aegyptopithecus, the three prosimian families are documented to date from only four specimens. Among all major groups of li ving and fossil euprimates, only the Malagasy lemuriforms, the Adapidae, and the New World monkeys now have no fossil record in the Oligocene of Egypt, making the Fayum area the most diverse in terms of primates of any region in the world

Primitive Old World monkey from the earliest Miocene of Kenya and the evolution of cercopithecoid bilophodonty

Old World monkeys (Cercopithecoidea) are a highly successful primate radiation, with more than 130 living species and the broadest geographic range of any extant group except humans. Although cercopithecoids are highly variable in habitat use, social behavior, and diet, a signature dental feature unites all of its extant members: bilophodonty (bi: two, loph: crest, dont: tooth), or the presence of two cross-lophs on the molars. This feature offers an adaptable Bauplan that, with small changes to its individual components, permits its members to process vastly different kinds of food. Old World monkeys diverged from apes perhaps 30 million years ago (Ma) according to molecular estimates, and the molar lophs are sometimes incompletely developed in fossil species, suggesting a mosaic origin for this key adaptation. However, critical aspects of the group's earliest evolution remain unknown because the cercopithecoid fossil record before ∼18 Ma consists of only two isolated teeth, one from Uganda and one from Tanzania. Here we describe a primitive Old World monkey from Nakwai, Kenya, dated at ∼22 Ma, that offers direct evidence for the initial key steps in the evolution of the cercopithecoid dentition. The simple dentition and absence of bilophodonty in the Nakwai monkey indicate that the initial radiation of Old World monkeys was first characterized by a reorganization of basic molar morphology, and a reliance on cusps rather than lophs suggests frugivorous diets and perhaps hard object feeding. Bilophodonty evolved later, likely in response to the inclusion of leaves in the diet