Group Composition and Monandry in Grizzled Langurs, Presbytis comata, on Java

Abstract

Grizzled langurs, Presbytis comata, a largely sexually monomorphic species, are reported to occur in populations where either the majority of groups comprise 1 adult male with 1 adult female, or where groups comprise 1 adult male with multiple females. As such, they may have a monandrous mating system. I investigated whether 1-male/1-female groups indeed form a significant part of the species' social system, and whether habitat variation (forest fragment size, distance to the forest edge, altitude) affects social organization. I found the species from sea level to 2,565 m above sea level in groups from 1 to 13 individuals. I recorded mostly 1-male/multifemale groups with offspring or, alternatively, all-male groups. Two out of 55 groups comprised 1-male/1-female groups with offspring. Group size was negatively correlated with altitude and forest fragment size, and positively correlated with increasing distance from the forest edge. Altitudinal variation in group sizes was driven mainly by fewer adult females being present in groups at higher elevations; the number of adult males (almost invariably 1), subadults, juveniles, and infants, as well as the infant/adult female ratio, showed little altitudinal variation. One-male/1-female groups have been recorded repeatedly over a 25-year period in a high-altitude population on Mt. Patuha, West Java, but even here, on average, three fifths of the groups comprise 1 adult male with multiple females. At high-altitude sites, P. comata may indeed have a monandrous mating system, but at lower elevations it seems similar to that of other Presbytis langurs.

Does the Presence of Shade Trees and Distance to the Forest Affect Detection Rates of Terrestrial Vertebrates in Coffee Home Gardens?

“…The Endangered and largely arboreal grizzled langur is restricted to the western part of Java, where it is found from sea level up to 2500 m a.s.l. [44]. It is fully dependent on the last remaining patches of natural forest, but it still can come into conflict with humans there where the forest abuts the agroforests or forest plantations.…”

Presbytis neglectus or P. femoralis, Colobine Molecular Phylogenies, and GenBank Submission of Newly Generated DNA Sequences

“…Their work showed that more species were present on mainland Sumatra (6 rather than 3), that not P. potenziani from the Mentawai Islands but rather P. thomasi from northern Sumatra is the most basal species (contra, e.g. Brandon-Jones [1993]), that P. comata on Java [Nijman, 2017] is closely related to P. mitrata from Sumatra but not to P. thomasi or P. hosei from Borneo [contra, e.g. Chasen, 1940;Brandon-Jones, 1997] and that the Bornean endemic P. rubicunda is nested firmly in a group of Sumatran species, suggesting that only in the last 1.3 million years did they cross into Borneo.…”

Identifikasi Penyebab Ketidakhadiran Surili (Presbytis comata) pada Sebuah Ekosistem Kebun Campuran di Kabupaten Kuningan, Jawa Barat

“…Akan tetapi, sejauh ini, informasi yang tersedia sebagian besar masih tentang populasi surili di kawasan lindung karena banyaknya penelitian di kawasan tersebut (Heriyanto & Iskandar, 2004;Muhammad, 2016;Kusumanegara, Kartono, & Prasetyo, 2017;Widiana, Januari, Hasby, & Yuliawati, 2018;Handayani & Latifiana, 2019;Santosa, Rahmawati, & Utami, 2020;Eriska, 2021), demikian juga primata Colobine lainnya (Bismark, 2012;Ruskhanidar, Alikodra, Iskandar, Santoso, & Mansyoer, 2020). Terbatasnya informasi tentang surili di luar kawasan lindung (Nijman, 2017) telah menyulitkan program pelestarian dan konservasi populasi di kawasan tersebut (Doi & Takahara, 2016; Direktorat Jenderal Konservasi Sumberdaya Alam dan Ekosistem (Ditjen KSDAE), 2019).…”