These tiny antelope are monogamous living in pairs/family groups in a fixed territory which the males defend.
This image shows an adult male with its "crest" erected in display to a nearby rival. Note the pre-orbital scent gland which is used to smear smelly gunk onto grass stems to mark territory. Pairs also mark the periphery of their territories with dung middens. -An altogether delightful wee beastie!

The snout & enlarged nasal cavity is actually an intricate cooling mechanism which helps prevent the animal from overheating without excessive water loss.