A new paper in the American Journal of Primatology reports on new instances of adult female Sumatran orangutans eating slow lorises.
From the paper:
We report 3 rare cases of meat-eating of slow lorises, Nycticebus coucang, by 1 Sumatran orangutan mother–infant dyad in Ketambe, Indonesia, to examine how orangutans find slow lorises and share meat.
In the video below, you can see a female after she knocked a slow loris out of a tree and bit it on the head (probably to avoid getting bitten herself since lorises have poisonous saliva), then carried it back to eat in the tree and try not to share it with her infant.
As Madeleine Hardus at the University of Amsterdam et al report:
The mother often rejected meat sharing requests and only the infant initiated meat sharing.
Unlike chimpanzees, who hunt when fruit and their energy are abundant, the authors of this paper found orangs hunt only when fruit is scarce.
Slow loris captures occurred only during low ripe fruit availability, suggesting that meat may represent a filler fallback food for orangutans.
The authors also found that orangutans eat their meat more than twice as slowly as chimpanzees. Does this signify anything for human evolution?
Using orangutan data as a model, time spent chewing per day would not require an excessive amount of time for our social ancestors (australopithecines and hominids), as long as meat represented no more than a quarter of their diet.
Still, it’s way better to tickle your slow loris than eat it, even slowly.