Top | CV  | Publications | Study  | Gallery 

70. Hanya G, Bernard H (2021) Interspecific encounters among diurnal primates in Danum Valley, Borneo. International Journal of Primatology 42: 442-462. DOI: 10.1007/s10764-021-00211-9

Polyspecific associations, in which individuals of multiple species move together, have not been reported in Asian primates. However, only one study in India has shown this lack of association quantitatively. We collected data on inter-species encounters among five species of diurnal primates in Danum Valley by censusing four predetermined routes of 9.9 km, covering 1544.3 km, and tracking red leaf monkeys (Presbytis rubicunda) for 423 h over 25 months. We tested the null hypothesis that the frequency and duration of encounters did not differ from chance levels. During censuses, we detected primates 373 times, and found two species on the same 100-m segment only six times. This frequency was not significantly different from the chance level. While following red leaf monkeys, the frequency of encounters was lower than expected by chance with Mueller's gibbons (Hylobates muelleri) but higher than expected by chance with Bornean orangutans (Pongo pygmaeus) in the non-fruiting season. Inter-species encounters accounted for 6.4% of tracking time, and the encounter duration was significantly longer than expected by chance for orangutans. Red leaf monkeys did not change their rate or direction of travel upon meeting another species. We could not distinguish the association between red leaf monkeys and orangutans in the non-fruiting season from the possibility that the two species were independently attracted to the same place. In conclusion, we show the absence of active and consistent polyspecific association and identify avoidance in some species-pairs in an Asian primate community.

Key words: community ecology; gas model; inter-species relationships; polyspecific association; ranging

<Written by: Goro Hanya (hanya.goro.5z<atmark>>
<Contact: Goro Hanya (hanya.goro.5z<atmark>>
<Last update: June 15, 2021>