The 88th Annual Meeting of the American Association of Physical Anthropologists (2019)

Effect of Reproduction on Javan Slow Loris Mother’s Activity Budget and Ranging Behavior


1Department of Anthropology, Oxford Brookes University, 2Little Fireface Project, Java, Indonesia, 3Faculty of Forestry, Universitas Gadjah Mada (UGM), Yogyakarta,Indonesia, 4Anthropology Department, Boston University

March 29, 2019 , CC Ballroom BC Add to calendar

Reproduction is an energetically taxing yet crucial process for all species survival. Prior research measuring behavioral changes throughout primate reproductive stages have focused on species with distinct reproductive states or seasonal reproduction. Slow lorises (Nycticebus spp.) demonstrate slow reproduction cycles relative to their body size and show little evidence of birth seasonality in the wild or captivity. Due to their unusual reproductive cycle, little is known about the effect each reproductive stage may have on the behavior of slow loris mothers.

Using a six-year data set focused on the Javan slow loris (N. javanicus) comprised of nine females and 41 live births between 2012 and 2018, we sought to identify any potential behavioral and ranging changes females may exhibit at varying reproductive stages. We defined four reproductive stages, (1) pregnant, (2) lactating, (3) overlapping, where mothers were lactating and pregnant, and (4) absent, where females did not fit into the previous categories. Our results suggest that social activity are influenced by reproductive stage (p = 0.020) and significantly decrease when pregnant compared to absent periods (p = 0.025). Home ranges also significantly differed (p = 0.03) in the period prior to birth (mean: 5.0 ha, min-max: 1.7-9.9 ha) and non-reproductive periods (mean: 8.5 ha, min-max: 5.2-19.2 ha). Similar to other primates with clear reproductive periods or seasonality, slow loris behavior and home range size are affected and likely mitigating the demands placed on mothers during their reproductive cycle.

PTES, Disney Worldwide Conservation Fund, Margot Marsh Biodiversity Foundation, MbZ Species Conservation Fund, National Geographic, and Cleveland, Phoenix, Omaha, Columbus and Augsburg Zoo.