So I guess my question -- why them and not other primates -- is pointless at the moment."Exactly what triggers hibernation is still an open question," said lead author Marina Blanco a postdoctoral researcher at the Duke Lemur Center.
I know I wouldn't feel comfortable giving an answer at the moment. My guess is that it is in some way connected to Madagascar's unique environment. But I'm interested to read future studies.
these are strepsirrhines so perhaps <- this is the word that removes culpability for all my wild speculation this is a hold-over from the insectivorous squirrelly primate clade founder artists reconstruction
hibernation could be an ancestral rather than derived trait. Malagasy niches possibly are closer to those of Africa before the opening of the Mozambique Channel (emergence of mega-predators being a big change.) We need to find a Galago that does it and see if the hibernation is regulated by the same mechanisms.