In the latest (10/25/14) NewScientist, a piece “Shy lemurs communicate using toilet trees” (on-line; in print with the jokey title “Wee need to stay in touch”):
The white-footed sportive lemur does not need to see its family often – it keeps in touch by urinating instead.
Unlike many other primates, these lemurs do not groom each other. They do not share their tree hideouts with others, and go to great lengths to avoid spending time with the mates and offspring they share their territory with.
… Iris Dröscher of the German Primate Centre in Göttingen spent over 1000 hours watching the toilet habits of 14 adult sportive lemurs, and found that family groups went to the same places to defecate and urinate at different times throughout the night (Behavioral Ecology and Sociobiology …). “The chemical traces in the urine are unique for each lemur, so by leaving scent marks the lemurs can interact and bond with their family without meeting them,” says Dröscher.
Two things here: the delightful name white-footed sportive lemur, and of course their means of communication.