Twenty-three-year demographic history of the Affenberg Japanese macaques (Macaca fuscata), a translocated semi-free-ranging group in southern Austria

Abstract

Demographic studies on translocated primate groups provide a unique opportunity to study population dynamics, social strategies, and reproductive parameters of a species adapting to new environments. In 1996, 38 Japanese macaques (Macaca fuscata) of the Minoo-H group (Osaka Prefecture, Japan) were translocated to Affenberg Landskron, a four-hectare naturally forested park in southern Austria. By January 2020, the population had increased to 160 individuals, and a total of 223 births were recorded. Births peaked in late April to late May, and the timing was influenced by neither offspring sex nor parity status of the mother. Infant mortality was low (8.97%), mostly involving primiparous females, and the average interbirth intervals were shorter following the death of an infant (1.10 years) than a surviving infant (1.77 years). Females rarely had offspring with the same males repeatedly, and the reproductive success among males declined with increasing years of presence in the group. The main aspects of reproduction, mortality, and mate choice are consistent with published data on natural and provisioned populations in Japan and those translocated to other countries. The life expectancy for females, however, was relatively high (11.72% chance of reaching the age of 20), whereas birth control prevented them from using their lifetime reproductive potential. By January 2020, the number of old individuals (> 18 years; 17.5%) was close to that of juveniles (< 4 years; 22.5%). The specific group composition, along with the inability of males to emigrate out of their natal group, may affect the social dynamics of the population, which merits further attention in future studies.

Prosociality in a despotic society

“…Kin favoritism and nepotism are integral properties of Japanese macaques and, in general, despotic societies (11, 37, 38). Our study group followed species-typical matrilineal norms, i.e., the presence of distinct hierarchical ranks and order (25, 39, 40). As hypothesized, kinship was found to influence prosociality, though it did not predict the propensity or likelihood of prosocial provisioning, suggesting a general tendency to help group members.…”

A novel methodological approach for group classification during fission of a semi‐free‐ranging group of Japanese macaques (Macaca fuscata)

“…The most recent data on male social rank before fission was collected in 2018 (Schmidhuber, unpublished data). Nevertheless, Pflüger et al (2021) found the male dominance hierarchy in the Affenberg-group to be very stable concerning high-ranking positions, and that it followed a gradual succession of alpha-positions.…”

“…The Affenberg‐group originates from a wild group that was translocated from Minoo to Affenberg, Austria in 1996. The demographic development, population dynamics, social characteristics, and reproductive parameters of this group have been extensively documented since their arrival at Affenberg (Pflüger et al, 2021 ).…”

“…The most densely vegetated P‐areas were not used as sites for provisioning. Additional information concerning the habitat, provisioning, and management of the Affenberg‐group is described in detail by Pflüger et al ( 2021 ).…”

“…Japanese macaques travel to their sleeping spots shortly before and after dusk (Wada et al, 2007 ). At the study site, the sleeping spots are in high trees (up to 30 m height; Pflüger et al, 2021 ) with no possibility to identify the macaques individually given the lack of monitoring cameras.…”