Published in Folia Primatologica
Explanations for the brain size increments through primate and, particularly, human evolution are numerous. Commonly, these hypotheses rely on the influence that behavioral and ecological variables have on brain size in extant primates, such as diet quality, social group size, or home range (HR) area. However, HR area does not reflect the time spen...
Published in Folia Primatologica
When monkeys, such as the toque macaques (Macaca sinica) of Sri Lanka, seek food on the ground near human habitation, they may use electrical posts to escape aggression from conspecifics, dogs, or humans. Shields mounted on electrical posts prevented monkeys from reaching the electrical wires, thereby averting their electrocution: the frequency of ...
Published in Folia Primatologica
This study presents the first evidence of effects of applying both positive and negative stimuli simultaneously on visual laterality in Old World monkeys. Thirteen captive individuals of Sichuan snub-nosed monkeys (Rhinopithecus roxellana) were chosen as focal subjects in the monocular box task. In total, 4 emotional categories (the preferred, the ...
Published in Folia Primatologica
We compared the characteristics of seeds within faeces between semi-terrestrial Japanese macaques (Macaca fuscata) and sympatric arboreal Japanese martens (Martes melampus) in Shiga Heights, central Japan. We collected faecal samples of the two mammalian species for 1 year (n = 229 for macaques and n = 22 for martens). We then compared the proporti...
Published in Folia Primatologica
Affiliative vocalizations occur across primate taxa and may be used to maintain spatial cohesion and/or to regulate social interactions in group-living species. For gregarious strepsirhines like the ring-tailed lemur (Lemur catta), with large vocal repertoires and several distinct affiliative vocalizations including the chirp and wail, it is import...
Published in Folia Primatologica
The nocturnal mouse and dwarf lemurs from Madagascar are known to express heterothermy. Whereas dwarf lemurs (Cheirogaleus) are obligate hibernators, mouse lemurs (Microcebus) can express a great range of heterothermic responses, including daily torpor, prolonged torpor or hibernation, depending on the species, population or individual. Although th...
Published in Folia Primatologica
Previous primate research has demonstrated social learning related to accepting novel foods, but little evidence suggests social learning of food avoidance. Ring-tailed lemurs (Lemur catta)have been observed to shake their heads rapidly in response to sour and bitter stimuli. This study investigated whether this head-shaking behavior may have a soc...
Published in Folia Primatologica
Adult males of some primate species are known to positively interact with juveniles. In cases where paternal certainty is high, these behaviors have been largely attributed to the paternal investment hypothesis. Males have also been observed to interact with nonkin juveniles, which has often been explained in terms of mating effort. Here, we examin...
Published in Folia Primatologica
Madagascar’s dramatic climatic fluctuations mean most lemurs adjust behaviors seasonally as resource availability fluctuates. Many lemurs will adopt one of two strategies, a resource maximizer or an area minimizer, when adjusting to seasonal shifts in resource availability. However, it is unknown if and how aye-aye (Daubentonia madagascariensis) ra...
Published in Folia Primatologica
Social rank is positively correlated with reproductive success in numerous species, albeit demographic factors often influence those patterns. In multimale primate species, reproductive skew tends to decrease with increasing numbers of males and sexually receptive females. Alpha male chimpanzees (Pan troglodytes) often sire a disproportionate, thou...
