The Social Repertoire of Sulawesi Macaques

Abstract

The social repertoire of Sulawesi macaques is presented, based upon data recorded both in the wild and from captive populations. The repertoire describes behaviors observed in social contexts, including communication patterns, movement patterns, sexual patterns, infant-related and play behaviors, and triadic interactions. Most of these behavior patterns are shared by all known Sulawesi taxa. The form or function of certain patterns depart significantly from what has been reported in other macaques, while particular similarities may be linked to phylogenetic relationships within the genus Macaca. INTRODUCTION Much of the scientific endeavor consists in testing hypotheses and theories. However, the study of animal behavior is usually based in behavioral units which are qualitatively recognized, more or less arbitrarily defined, and not attached to explicit hypotheses. The subjective nature of behavioral units makes the establishment of the behavioral repertoire of species a neglected task. Description of behavior is usually considered a preliminary research task rather than an end in of itself. However, knowledge of basic patterns is as necessary to the study of behavior as detailed descriptions of forms are to anatomy. Ethograms must be viewed as tentative inventories to which additions and refinements should be continuously brought, with every advance diminishing the extent of subjectivity in our accounts (Coehlo & Bramblett, 1989). The present paper presents such a behavioral inventory for Sulawesi macaques. It should be considered both a tool and an end result. Several macaque taxa live on the island of Sulawesi in Indonesia. They belong to the silenus-sylvanus lineage, one of the three phyletic radiations recognized in the genus Macaca (Fooden, 1976; Delson, 1980; Hoelzer & Melnick, 1996). This lineage includes the Barbary macaque (M. sylvanus), the lion-tailed macaque (M. silenus), the pig-tailed macaque (M. nemestrina) and the Sulawesi macaques. Sulawesi taxa share many morphological, physiological, and molecular features, and are probably derived from a single ancestral population (Fooden, 1969; Fooden & Lanyon, 1989; Kawamoto, 1996; Evans et al., 1999). Currently, secondary intergradation is evidenced by the hybridization occurring on the border areas between taxa ranges (Albrecht, 1978; Groves, 1980; Camperio Ciani et al., 1989; Watanabe & Matsumura, 1991; Watanabe et al., 1991; Froehlich & Supriatna, 1996; Bynum et al., 1997). The evolutionary diversification of Sulawesi taxa possibly originated from the temporary isolation of different parts of the island in geological time (Fooden, 1969; Bynum et al., 1997). Sulawesi taxa are variously classified as four (Groves, 1980) or seven species (Fooden, 1969). We provisionally retain Fooden's nomenclature, which distinguishes the following species: crested macaque (M. nigra), Gorontalo macaque (M. nigrescens), Heck's macaque (M. hecki), Tonkean macaque (M. tonkeana), moor macaque (M. maurus), booted macaque (M. ochreata), and Muna-Buton macaque (M. brunnescens). These seven taxa are generally allopatrically distributed over the island (Fig. 1), and may be found in both lowland and lower montane forests (Whitten et al, 1987; Supriatna et al., 1992).