Population of Proboscis Monkey (Nasalis lavatus) in Manggar River, Balikpapan City, Indonesia

A population estimation of proboscis monkeys (Nasalis larvatus) has been conducted in Manggar River, Balikpapan. In this non-conservation area, the anthropogenic activities threaten the proboscis monkey habitat. Boat survey technique was applied along ± 17 km of the river in the morning and evening. The number of proboscis monkeys in the surveyed area was estimated to range from 57 to 69 individuals with estimated population density of 4.75 individuals/Km2. Moreover, the population of this primates was divided into 4 groups and the sex ratio between adult males and females was 1:2.33. The proboscis monkeys were distributed in the middle of the river to the upstream. The highest population was found in the upstream area with less human activities. Conservation efforts in the Manggar River need to be carried out considering the proboscis monkey habitat in the area has been fragmented and isolated. These efforts could involve local economic communities.

Apparent diet digestibility of captive colobines in relation to stomach types with special reference to fibre digestion

Colobine monkeys are known for the anatomical complexity of their stomachs, making them distinct within the primate order. Amongst foregut fermenters, they appear peculiar because of the occurrence of two different stomach types, having either three (‘tripartite’) or four (‘quadripartite’, adding the praesaccus) chambers. The functional differences between tri and quadripartite stomachs largely remain to be explained. In this study, we aim to compare the apparent digestibility (aD) in tripartite and quadripartite colobines. Hence, we measured the aD in two colobine species, Nasalis larvatus (quadripartite) and Trachypithecus cristatus (tripartite), in two zoos. We also included existing colobine literature data on the aD and analysed whether the aD of fibre components is different between the stomach types to test the hypothesis of whether quadripartite colobines show higher aD of fibre components than tripartite colobines did. Our captive N. larvatus specimen had a more distinctively varying nutrient intake across seasons with a larger seasonal variation in aD than that of a pair of T. cristatus, which mostly consumed commercial foods with a lower proportion of browse and less seasonal variation. We observed higher aD of dry matter (DM), neutral detergent fibre (NDF) and acid detergent fibre (ADF) in the N. larvatus specimen, suggesting a higher gut capacity of N. larvatus provided by the additional praesaccus forestomach chamber. Based on the analysis of literature data for aD, we also found that quadripartite species achieved higher fibre digestibility at similar dietary fibre levels compared with tripartite species, supporting the hypothesis that the additional gut capacity offered by the praesaccus facilitates a longer retention and hence more thorough microbial fermentation of plant fibre.

A preliminary study on semen collection, its evaluation, and testicular and sperm morphometries in the wild proboscis monkey (Nasalis larvatus)

Introduction The proboscis monkey (Nasalis larvatus) is an endangered species with a declining population. This article describes the first successful attempt at sperm collection and evaluation, and the testicular and sperm morphometries of the wild proboscis monkey in Sabah, Malaysia. Material and Methods Eight semen collection procedures using electro-ejaculation and digital manipulation were conducted in three wild adult male proboscis monkeys. A total of 21 ejaculates were collected. The testicular biometry was measured with the aid of ultrasonography. Sample evaluation included semen volume and pH and sperm concentration, viability, and abnormality. The sperm morphometry was undertaken using phase contrast microscopy. Results The mean (±SD) total testicular volume of these animals was 5.77 cm3 (±1.58). Semen collection by electro-ejaculation resulted in an 84% success rate, while digital manipulation did not result in any ejaculation. Each animal showed different semen characteristics, where the volume was 5–540 μL, pH 8–9, and sperm concentration 0.041–83.00 ×106/mL. The percentage of abnormal sperm was high at 76.8% (±89.60), largely due to midpiece abnormality. Normal sperm had a spherical head and long tail with a head : midpiece : tail length ratio of 1 : 2: 8. Conclusion The social status of these animals may contribute to the generally low quality of the semen. The techniques and data from this study are useful for future conservation and application of assisted reproductive technology in this species.

REKOMENDASI PENETAPAN KAWASAN EKOSISTEM ESENSIAL DI DESA PANJARATAN

Essensial Ecosystem Areas in general can be interpreted as protected areas outside conservation areas. In Panjaratan Village, it is found an area that is a habitat for proboscis monkeys and other animals according to the results of the inventory but is outside the conservation forest area. The existence of proboscis monkey (Nasalis larvatus) habitat in Panjaratan Village needs to supported in conservation so that it does not experience extinction due to interference for human activities. This study aims to provide recommendations in planning the determination of essential ecosystem areas for the Nasalis larvatus habitat in Panjaratan Village. This research was qualitative by using an emic approach that focuses on data and analysis based on answers from key informant. The results showed that the presence of Nasalis larvatus habitat in Panjaratan Village received support from the community, government and the private sector in its empowerment activities. This is supported by the existence of an inventory and verification of the presence of Nasalis larvatus habitat in Panjaratan Village conducted by the South Kalimantan Natural Resource Conservation team and through identification activities to then propose the Nasalis larvatus habitat area in the village to become an area of essential ecosystem areas.

SEBARAN POHON PAKAN DI HABITAT BEKANTAN (Nasalis larvatus Wurmb.) DI HUTAN RIPARIAN AREAL PERTAMBANGAN PT JORONG BARUTAMA GRESTON

The variety of proboscis monkey habitat causes the composition of plants, the preparation of different habitats, including the type of feed and its composition. The aim of this research is to map the distribution of proboscis monkeys and inventory the proboscis monkeys. Retrieval of vegetation data is placed in an area where frequent activity of proboscis monkeys occurs. Data collection was carried out to determine tree species and undergrowth as macro habitat as well as the potential source of proboscis food that includes the leaves, buds, flowers, fruit or parts that are being eaten or already eaten. Sampling of feed tree sampling data using accidental sampling method is a method of recording accidentally or accidentally when finding proboscis probes that are eating or traces of food. The coordinates of the meeting point with the proboscis feed tree are made into the distribution map of the proboscis feed tree using GIS software. There are 9 distribution locations and 13 species of plants whose parts are eaten by proboscis monkeys in the Riparian forest of PT JBG areas such as Ficus racemosa, Hibiscus tiliaceus, Gluta renghas, Albizia chinensis, Eugenia sp, Uncaria sp, Dillenia indica, Oxyceros longifer, Syzigium sp, Calamus sp, Macaranga bancana, Premna corymbusa, Centrosema pubescens. These types are divided into two levels of vegetation, namely forage trees and undergrowth with edible parts such as shoots, leaves, flowers, fruit and umbut Habitat bekantan yang bervariasi menyebabkan komposisi jenis tumbuhan penyusunan habitat berbeda-beda, termasuk jenis pakan dan komposisinya. Penelitian ini bertujuan untuk melakukan pemetaan sebaran pohon pakan bekantan dan menginventarisasi jenis pohon pakan bekantan. Pengambilan data vegetasi diletakkan pada areal yang sering terjadi aktivitas bekantan. Pengambilan data dilakukan untuk menentukan jenis pohon dan tumbuhan bawah sebagai habitat makro serta potensi sumber pakan bekantan yang meliputi bagian daun, pucuk, bunga, buah atau bagian yang sedang dimakan atau sudah dimakan. Pengambilan data sampling pohon pakan menggunakan metode accidental sampling yaitu metode pencatatan secara kebetulan atau tidak sengaja saat menemukan bekantan yang sedang makan atau jejak bekas makanan.pada lokasi tempat ditemukannya pohon pakan atau bekas makanan bekantan lalu ditandai titik koordinatnya menggunakan GPS. Koordinat titik pertemuan dengan pohon pakan bekantan dibuat menjadi peta sebaran pohon pakan bekantan dengan menggunakan software GIS. Terdapat 9 titik lokasi persebaran dan 13 jenis tumbuhan yang bagian-bagiannya dimakan oleh bekantan di hutan Riparian areal PT JBG seperti jenis Ficus racemosa, Hibiscus tiliaceus, Gluta renghas, Albizia chinensis, Eugenia sp, Uncaria sp, Dillenia indica, Oxyceros longifer, Syzigium sp, Calamus sp, Macaranga bancana, Premna corymbus, Centrosema pubescens. Jenis-jenis ini terbagi menjadi dua tingkatan vegetasi yaitu pohon pakan dan tumbuhan bawah dengan bagian yang dimakan seperti pucuk, daun, bunga, buah dan umbut.

Lactobacillus nasalidis sp. nov., isolated from the forestomach of a captive proboscis monkey (Nasalis larvatus)

Three strains (YZ01T, YZ02 and YZ03) of Gram-stain-positive, facultatively anaerobic rods were isolated from the forestomach contents collected from a captive male proboscis monkey (Nasalis larvatus) at Yokohama Zoo in Japan. Phylogenetic analysis of the 16S rRNA gene sequences revealed that these strains belonged to the genus Lactobacillus . Based on the sequence similarity of the 16S rRNA gene, Lactobacillus delbrueckii subsp. indicus JCM 15610T was the closest phylogenetic neighbour to YZ01T. Sequence analyses of two partial concatenated housekeeping genes, the RNA polymerase alpha subunit (rpoA) and phenylalanyl-tRNA synthase alpha subunit (pheS) also indicated that the novel strains belonged to the genus Lactobacillus . The average nucleotide identity and digital DNA–DNA hybridization (dDDH) between L. delbrueckii subsp. indicus and YZ01T were 85.9 and 31.4 %, respectively. The phylogenetic tree based on the whole genomic data of strains YZ01T, YZ02 and YZ03 suggested that these three strains formed a single monophyletic cluster in the genus Lactobacillus , indicating that it belonged to a new species. The DNA G+C content of strain YZ01T was 51.6 mol%. The major fatty acids were C16 : 0 and C18 : 1 ω9c. Therefore, based on phylogenetic, phenotypic and physiological evidence, strains YZ01T, YZ02 and YZ03 represent a novel species of the genus Lactobacillus , for which the name Lactobacillus nasalidis sp. nov. is proposed with the type strain YZ01T (=JCM 33769T=DSM 110539T).

Apparent digestibility of captive colobines in relation to stomach types with special reference to fibre digestion

Colobine monkeys are known for the anatomical complexity of their stomachs, making them distinct within the primate order. Amongst foregut fermenters, they appear peculiar because of the occurrence of two different stomach types, having either three (‘tripartite’) or four (‘quadripartite’, adding the praesaccus) chambers. The functional differences between tri and quadripartite stomachs largely remain to be explained. In this study, we aim to compare the apparent digestibility (aD) in tripartite and quadripartite colobines. Hence, we measured the aD in two colobine species, Nasalis larvatus (quadripartite) and Trachypithecus cristatus (tripartite), in two zoos. We also included existing colobine literature data on the aD and analysed whether the aD of fibre components is different between the stomach types to test the hypothesis of whether quadripartite colobines show higher aD of fibre components than tripartite colobines did. Our captive N. larvatus specimen had a more distinctively varying nutrient intake across seasons with a larger seasonal variation in aD than that of a pair of T. cristatus, which mostly consumed commercial foods with a lower proportion of browse and less seasonal variation. We observed higher aD of dry matter (DM), neutral detergent fibre (NDF) and acid detergent fibre (ADF) in the N. larvatus specimen, suggesting a higher gut capacity of N. larvatus provided by the additional praesaccus forestomach chamber. Based on the analysis of literature data for aD, we also found that quadripartite species achieved higher fibre digestibility at similar dietary fibre levels compared with tripartite species, supporting the hypothesis that the additional gut capacity offered by the praesaccus facilitates a longer retention and hence more thorough microbial fermentation of plant fibre.

STRUKTUR POPULASI BEKANTAN (NASALIS LARVATUS) DI RAWA GELAM

Number of proboscis monkey population in Cajuputi Swamp Forest is 258 individual. This population is strongly influenced by condition of its habitat which is to degradation to 3.417 hektar. The object of research is to analyzed structure of proboscis monkey population. Method of research are river survey (Sha et al, 2008) and concentration count (Anonymous, 1981; Alikodra, 2002). The avarage density of proboscis monkey in their homerange is 3 individuals/hectares, with 30,2% males and 48,5 % females. This population is slow growth because there is only one baby/year, this is also indicated by number of 14 individuals babies (5,4%) and 41 infant (15,9%) lower when compared to number of adult indiviuals, so it is very worryng for continued growth of the population.