Details

Autor(en) / Beteiligte

• Scott, Amy M.
• Susanto, Tri Wayhu
• Setia, Tatang Mitra
• Knott, Cheryl D.

Titel

Mother‐offspring proximity maintenance as an infanticide avoidance strategy in bornean orangutans (Pongo pygmaeus wurmbii)

Ist Teil von

• American journal of primatology, 2023-06, Vol.85 (6), p.e23482-n/a

Ort / Verlag

United States: Wiley Subscription Services, Inc

Erscheinungsjahr

2023

Quelle

Wiley Online Library - AutoHoldings Journals

Beschreibungen/Notizen

• Sexually‐selected infanticide by males is widespread across primates. Maternal protection is one of many infanticide avoidance strategies employed by female primates. Bornean orangutan (Pongo pygmaeus wurmbii) mothers with younger offspring are less social with males than mothers with older offspring. Additionally, the distance between a mother and offspring decreases in the presence of male conspecifics, but not female conspecifics. We hypothesized that mothers are responsible for the change in mother‐offspring proximity when males are present. Using a year of behavioral data from orangutans in Gunung Palung National Park, we tested whether the Hinde Index, a ratio of the number of approaches and leaves between two individuals, was indicative of mother or offspring proximity maintenance across different social groupings. The semi‐solitary social organization of orangutans allows us to observe different social groupings. We found that the mother‐offspring Hinde Index was typically indicative of offspring maintenance of proximity. However, the presence of male conspecifics was associated with an increase in the Hinde Index which indicates that mothers are responsible for the decrease in mother‐offspring distance when males are present. The decrease in mother‐offspring distances and increase in Hinde Index when males are present indicates that mothers react to the presence of males in a protective manner. We suggest this may be an infanticide avoidance behavior by mother orangutans. Measuring mother‐offspring proximity using the Hinde Index shows that for Bornean orangutans, mothers are responsible for shortening the distance with their offspring when males are present. Outline denotes responsibility for proximity maintenance. Photos © Tim Laman or Amy Scott RESEARCH HIGHLIGHTS Male presence is associated with a change in mother‐offspring distance and proximity maintenance in Bornean orangutans The Hinde Index shows that mother orangutans reduce the distance between themselves and their offspring when males are present Proximity maintenance is maternal protection from a potential infanticidal threat