maintain the position of the individual. Other modes of locomotion used by the species include climbing, quadrupedal walking, hopping and "cantilevering." Horsfield's tarsier is monogamous, with a copulation frequency during estrus of once per night. Courtship calls are performed by the male and he emits 2-3 chirrups while opening and closing the mouth. This call happens within 5 minutes of looking at the female. Once the male gives his courtship call, if the female is receptive, she will perform genital displays to him. If the female is not in estrus, she will emit an agonistic call which is often followed by biting and pushing the male away. Both sexes' calls last on average for 1 second, and the interval between calls is on average 3 seconds. Infants are born with their eyes open and fully furred and are able to groom themselves. The mother will carry her infant in her mouth and when she forages for food the mother will park the infant on a branch. Infant sounds are mostly clicks: "k", "tk", "ki", or a rapid "kooih" and can be heard when the infant is left alone or is cold. The mother stays in contact with their infants using high-pitched calls. Infants were found to first use the tails as support during resting at 7–10 days. Young leave their range at the onset of puberty, and find their own territory. Social grooming in this species only occurs between mothers and infants, removing dead skin and parasites by scratching with their toe claws and licking their fur, avoiding their faces. Faces are cleaned by rubbing on branches and it is to reinforce social bonds. Horsfield's tarsier marks its territory with scents from urine and glandular secretions on a substrate while scratching the surface with its hind-limb toe claws. Conservation status The rapid loss of habitat due to forest conversion, oil palm plantations, fire and logging is cause for concern. Additionally, the species is also collected for the illegal pet trade and wrongly considered a pest to agricultural crops. It can suffer, directly and indirectly, from the use of agricultural pesticides. Horsfield's tarsier is listed as vulnerable in the 2008 IUCN Red List of Threatened Species, listed in CITES Appendix II, and protected by law in Indonesia and in Malaysia. In February 2007, the governments of Brunei, Malaysia, and Indonesia agreed to protect roughly of tropical forest in the "Heart of