Out of a group of 12 M. nemestrina (originating from Malaysia), 9 adults had shown clinical signs induced by ILS at 25 c/sec. Six of them (3 males, 3 females) were very photosensitive; however, only 2 presented eyelid and/or head jerks after the end of ILS (level 4), but never a generalized seizure. Tactile periorbital stimuli favoured myoclonus. In all but the two of level 4, the intensity of clinical signs varied from one day to the next. In all implanted adult macaques, spontaneous paroxysmal EEG activities were seen during slow sleep in mostly anterior areas, but also during waking and REM sleep in some of them; however, their occurrence depended upon the individual and were not in all cases related to their level of photosensitivity. During ILS, paroxysmal discharges (spikes and waves and/or polyspikes and waves), isolated or in bursts at 3-4/sec were bilateral and symmetrical. They started in fronto-rolandic regions, then became generalized. This observation constitutes a new fact since the discovery, in 1966, of the photomyoclonic syndrome of Papio papio, Macaca nemestrina being another species of subhuman primates with a marked predisposition to photosensitive epilepsy.
A breeding colony utilizing a harem mating system was established to study the feasibility of breeding cynomoglus monkeys, Macaca fascicularis, in Malaysia. Two groups consisting of 10 females and one male each were evaluated over a 3 period. Forty births were recorded; one was stillborn, 11 died while nursing, and 28 were weaned. The average time to wean offspring was 230 days with an average weight at weaning of 0.858 kg. The average time for conception to take place after weaning was 50 days. Of the 20 breeder females, six produced three offspring each, nine produced two offspring each, four produced one offspring each and one remained barren throughout the project. Three different weaning systems were evaluated. The best method was caging the mother-infant pair within or adjacent to the breeding room followed by a two-part cage system which allowed the infant to continue nursing and also obtain solid food inaccessible to the mother.
Many species of terrestrial animals, including primates, live in varied association with the aquatic (e.g., riverine or coastal) environment. However, the benefits that each species receive from the aquatic environment are thought to vary depending on their social and ecological characteristics, and thus, elucidating those benefits to each species is important for understanding the principles of wild animal behaviour. In the present study, to gain a more complete picture of aquatic environment use, including social and ecological factors in primates, factors affecting riverine habitat utilization of two macaque species (Macaca nemestrina and M. fascicularis) were identified and qualitative comparisons were made with sympatric proboscis monkeys (Nasalis larvatus), which have different social and ecological characteristics. Temporal variation in sighting frequency of macaques at the riverbanks was positively related to the fruit availability of a dominant riparian plant species and negatively related to the river water level which affects the extent of predation pressure. Riverine utilization of macaques was greatly influenced by distribution and abundance of food (especially fruit) resources, possibly in association with predation pressure. Additionally, qualitative ecological comparisons with sympatric proboscis monkeys suggest that the drivers of riverine utilization depend on the feeding niches of the species, and different anti-predator strategies resulting from their differing social structures.
In primates, living in an anthropogenic environment can significantly improve an individual's fitness, which is likely attributed to access to anthropogenic food resources. However, in non-professionally provisioned groups, few studies have examined whether individual attributes, such as dominance rank and sex, affect primates' ability to access anthropogenic food. Here, we investigated whether rank and sex explain individual differences in the proportion of anthropogenic food consumed by macaques. We observed 319 individuals living in nine urban groups across three macaque species. We used proportion of anthropogenic food in the diet as a proxy of access to those food resources. Males and high-ranking individuals in both sexes had significantly higher proportions of anthropogenic food in their diets than other individuals. We speculate that unequal access to anthropogenic food resources further increases within-group competition, and may limit fitness benefits in an anthropogenic environment to certain individuals.