Sexual Behaviour of the Spectral Tarsier (Tarsius spectrum) in Captivity

Abstract

Tarsius spectrum is a primate species endemic to Sulawesi. Populations of the species have decreased due to habitat destruction and hunting. The sexual behaviour of T. bancanus and T. syrichta are known, but that of T. spectrum has not been reported until recently. The aim of this research was to study the sexual behaviour of T. spectrum in captivity. We observed 3 pairs of T. spectrum at the captive breeding facility of the IPB Primate Research Centre for 9 months using focal animal sampling. We showed that principal courtship behaviours were scent marking (36.7%) and genital marking for females (16.2%) and genital inspection for males (16.0%). Copulations lasted between 3 and 4 min, starting with the male mounting the female and thrusting quickly as many as 168–236 times followed by slow thrusting 9–20 times. When slow thrusting occurred, females vocalized up to 6 times. At the end of the copulation sequence, males remained motionless with their penis inserted within the female’s genitalia for about 31 s. Copulation occurred only once for each pair during the observation period. Our results should be useful to support breeding programmes and conservation actions for tarsiers.

Assessing female reproductive status of spectral tarsier (Tarsius tarsier) using fecal steroid hormone metabolite analysis

“…Specifically, Gursky () reported for the same species as here a gestation length of 186–199 days based on the occurrence of copulations and the timing of birth in wild animals. Given that copulations in T. tarsier occur on only 1 day of the ovarian cycle (Hidayatik et al, ; Wright et al, ), it is conceivable that copulations can be easily missed, particularly in animals in the wild where observation conditions are presumably more difficult due to the species' nocturnal life style. The gestation length given by Gursky () may, therefore, represent an overestimation.…”

“…When estrus was anticipated (i.e., by an increase in male sexual interest and female jumping behavior; see below), we conducted additional observations during three consecutive days to cover the full estrus period. Parameters of sexual behavior in this study were taken from the ethogram described for T. tarsier in Hidayatik et al () as follows: “Scent/urine mark”: female urinates onto substrate, scratching surface with hindlimb toe claws; “Genital mark”: female rubs its vulva on a substrate, depositing vaginal or gland secretions; “Genital inspection”: male licks or sniffs female genitalia; “Olfactory investigation”: male licks or sniffs female genital mark or female urine mark; “Female avoidance”: (1) Agonistic call: female emits harsh chatter during genital sniffing by male; (2) Agonistic action: female pushes male with forelimb and/or bites male when being approached from the front or back; (3) Jump: female jumps away when male tries to start genital inspection or olfactory investigation and/or when the male tries to approach; “Copulation“: male mounts female from behind on the back followed by intromission of the penis and thrusting and pulling until male dismounted the female.…”

“…The occurrence of behavioral estrus was determined on the basis of female and male socio‐sexual interactions. In this respect, the combined occurrence of increased levels of female and male proceptive behaviors (i.e., female scent/urine/genital marking, male inspection of the female markings and genitals), the occurrence of copulation and/or an increase in female jumping behavior (Figure ) were used to indicate that the female was or had just passed estrus (Hidayatik, Yusuf, Agil, Iskandar, & Sajuthi, ). Behavioral estrus was observed in all three females.…”