Movement Patterns of African Elephants (Loxodonta africana) in a Semi-arid Savanna Suggest That They Have Information on the Location of Dispersed Water Sources

Water is a scarce resource in semi-arid savannas where over half of the African elephants (Loxodonta africana) populations occur and may therefore influence their movement pattern. A random search is expected for an animal with no information on the location of the target resource, else, a direction-oriented walk is expected. We hypothesized that elephants movement patterns show a stronger directional orientation toward water sources in the dry season compared to the wet season. We investigated the movement paths of four male and four female elephants with hourly GPS fixes in Tsavo National Park, Kenya in 2012–2013. Consistent with our predictions, the movement paths of elephants had longer step lengths, longer squared net displacements, and were directed toward water sources in the dry season as compared to the wet season. We argue that African elephants know the location of dispersed water resources, enabling them to survive with scarce resources in dry savannas. These results can be used in conservation and management of wildlife, through for instance, protection of preferred water sources

Abrasive, Silica Phytoliths and the Evolution of Thick Molar Enamel in Primates, with Implications for the Diet of Paranthropus boisei

Background: Primates—including fossil species of apes and hominins—show variation in their degree of molar enamel thickness, a trait long thought to reflect a diet of hard or tough foods. The early hominins demonstrated molar enamel thickness of moderate to extreme degrees, which suggested to most researchers that they ate hard foods obtained on or near the ground, such as nuts, seeds, tubers, and roots. We propose an alternative hypothesis—that the amount of phytoliths in foods correlates with the evolution of thick molar enamel in primates, although this effect is constrained by a species ’ degree of folivory. Methodology/Principal Findings: From a combination of dietary data and evidence for the levels of phytoliths in plant families in the literature, we calculated the percentage of plant foods rich in phytoliths in the diets of twelve extant primates with wide variation in their molar enamel thickness. Additional dietary data from the literature provided the percentage of each primate’s diet made up of plants and of leaves. A statistical analysis of these variables showed that the amount of abrasive silica phytoliths in the diets of our sample primates correlated positively with the thickness of their molar enamel, constrained by the amount of leaves in their diet (R 2 = 0.875; p,.0006). Conclusions/Significance: The need to resist abrasion from phytoliths appears to be a key selective force behind the evolution of thick molar enamel in primates. The extreme molar enamel thickness of the teeth of the East African homini

Phylogeny of the titi monkeys of the Callicebus moloch group (Pitheciidae, Primates)

Callicebus is a Neotropical primate genus of the family Pitheciidae, which 27 currently comprises 34 recognized species. Based on their morphological traits 28 and geographic distribution, these species are currently assigned to five groups: the C. moloch, C. cupreus, C. donacophilus, C. torquatus, and C. 30 personatus groups, although in the past, alternative arrangements have been 31 proposed based on the analysis of morphological data. The principal 32 disagreements among these arrangements are related to the composition of the 33 C. moloch group. In the present study, we tested the different taxonomic proposals for the C. moloch group, based on the molecular analysis of nuclear 35 markers (Alu insertions and flanking regions) and three mitochondrial genes 36 (16S, COI and Cyt b), with a total of approximately 7 kb of DNA sequence 37 data. Phylogenetic reconstructions based on maximum likelihood and Bayesian inference methods indicated that the species of the current C. 39 cupreus group should be reintegrated into the C. moloch group. In addition, 40 our results corroborated previous studies suggesting that the species of the 41 current C. personatus group form a distinct species group. We also observed a 42 relatively subtle level of divergence between C. dubius and C. caligatus. While the known diversity of Callicebus is considerable, these findings 44 indicate that the relationships among groups and species may still not be 45 completely understood, highlighting the need for further research into the 46 biological, geographic and genetic variability of these primates, which will be fundamental to the effective conservation of the genu