Page 185 - Demo

Proceptive vocalisations in orang-utan females1838was born in LA Zoo on 10th of November 1968, and has been living in LA Zoo since then. Over time, she has been housed with multiple individuals, including different males. She gave birth to 4 offspring from 3 different males between 1978 and 1987. In our case description, we focus on the period from 1999 until approximately 2018, date after which she is considered to be of post-reproductive age (based on the absence of a regular menstrual cycle). During the period that we describe, she was housed with a flanged male, and with different females. Furthermore, she was not on contraceptives at any time during this period.Eloise has a condition similar to cerebral palsy, which she has had since birth. Her condition mostly affects her locomotion, since she has limited use of her hands and especially her feet. She has learned over her years how to modify her movements, and has generally locomoted by rolling or crawling. However, she has still been able to have a normal social life with conspecifics, and has been able to climb and manoeuvre throughout her exhibit space. Importantly, one of the authors of this manuscript (MF) was Eloise’s primary caregiver in the zoo during the period that we describe.Vocalisation analysesBioacoustic analyses were performed using Audacity software (Audacity Team, 2011). Measurements were taken of the total call length, inter-onset-intervals of the separate vocalisations, peak frequencies, and fundamental frequencies. Based on these parameters, the vocalisations of Temmy and Eloise were compared to other orang-utan calls obtained from Orangutan network of Universität Zurich (https://www.aim.uzh.ch/de/orangutannetwork.html; Hardus et al., 2009). Furthermore, we compared Temmy’s and Eloise’s call with male long calls recorded by James Askew (Askew, 2019; also see “Stimuli”). ResultsTemmyStudy period 1On the first day (24-5-2022) that we performed a playback experiment in the indoor enclosure with all orang-utans except Temmy, we noted that Temmy showed a strong behavioural reaction through a semi-transparent door that connected the indoor and outdoor enclosure. On this first day, we played 3 control calls, Tom Roth.indd 183 08-01-2024 10:42