Black bearded saki

The black bearded saki is endemic to the far eastern Amazon in Brazil, in a range restricted to a relatively small region from the Tocantins River in Pará east to around the Grajaú River in Maranhão (similar to the range of the equally threatened Kaapori capuchin). The natural home range of this species can vary from . It is the only Amazonian pitheciid found east of the Tocantins River. Studies show that it can adapt to a reduction in their habitat. ==Anatomy and morphology==

The black bearded saki can be identified by its thick black hair, distinctive beard that shapes the face, and a bushy fox-like tail. The tail is non-prehensible and it uses quadrupedal movement for locomotion. The black bearded saki has some yellowish-brown highlights around the back and shoulders and can weigh from . The black bearded saki is the only dark-nosed species of bearded saki with a blackish back, though some females and juveniles have a paler, brownish back. The teeth have evolved for seed predation: these dental adaptations allow then to crack and access seeds in extremely hard pods. They open hard-shelled fruits in a specialized, efficient process using their teeth. ==Behavior==

Diet The black bearded saki is highly frugivorous, specialized in seed predation as 90% of its diet comes from fruits and seeds. It complements its diet with fleshy fruits and small insects. This bearded saki uses its strong canine teeth to crack open hard shells of fruits and nuts, enabling it to access the unripe seeds inside the fruits. Social behavior It is a social animal, commonly grooming and playing with one another, even with other primate species. The black bearded saki can be found in troops of 20 to 30 individuals. Individuals of a troop will separate and rejoin throughout the day, have large home ranges, and travel long distances daily. Movement The black bearded saki spends most of its time resting, traveling and eating. The black bearded saki gives birth to offspring every 2 years. == Conservation ==

The black bearded saki is an endangered species. Forest fragmentation has resulted in behavioral changes that allow the species to adapt but could be detrimental for its conservation status in the long run. The ability to have a flexible diet and include seeds and unripe fruit helps this species survive in smaller forest fragments, but it appears that these conditions are unviable unless connectivity increases among the forest fragments and continuous forest in the landscape. The future survival of the black bearded saki will depend on adequate meta-population and habitat management. Habitat conservation is of top priority as this species has a particularly small range. The black bearded saki is considered the most endangered primate in the Amazon and is already locally extinct in a large portion of its original range. Future survival Studies performed at the Biological Dynamics of Forest Fragments Project study area have recorded the changes in behavior caused in black bearded sakis by habitat fragmentation. Groups of black bearded saki living in fragments of isolated rainforest showed a lack of reproduction in a period of 3.5 years. This might be due to a lack of resources in these small isolated fragments of habitat. Smaller fragments of forest also result in higher population densities. The increased density of bearded saki monkeys in the small fragments may affect their health. Higher density groups living in forest fragments are more prone to parasites and disease than those others living in undisturbed areas. It is unknown if the species will be able to reproduce and achieve healthy populations in the smaller patches of fragmented forest they are forced to inhabit. ==References==