Javan Slow Loris Population and Ecology at a New Site: Mendolo Forest, Central Java, Indonesia

Authors

  • Muhammad Yoga Saputra

    Department of Forest Management, Sebelas Maret University, Jl. Ir. Sutami 36 A, Kentingan, Surakarta 57126, Indonesia
  • Ike Nurjuita Nayasilana

    Department of Forest Management, Sebelas Maret University, Jl. Ir. Sutami 36 A, Kentingan, Surakarta 57126, Indonesia
  • Galuh Masyithoh

    Department of Forest Management, Sebelas Maret University, Jl. Ir. Sutami 36 A, Kentingan, Surakarta 57126, Indonesia
  • Arif Setiawan

    SwaraOwa, Berbah, Sleman 55573, Indonesia

DOI:

https://doi.org/10.30564/re.v7i4.9801
Received: 30 April 2025; Revised: 20 May 2025; Accepted: 9 June 2025; Published Online: 27 October 2025

Abstract

The Javan slow loris (Nycticebus javanicus) is a primate endemic to Java Island, Indonesia. Its conservation status has been categorized by IUCN as Critically Endangered, and it is included in Appendix I of CITES. Current population status and distribution remain unrecorded. The research was conducted in Mendolo Forest, Pekalongan Regency, Central Java Province, Indonesia, to estimate population size and distribution patterns. Data collection occurred September 15–19, 2024, using line transect methodology with spotlighting and GPS mapping. The transect locations are in each hamlet of Mendolo Village, namely Sawahan Hamlet with two transects, Mendolo Kulon Hamlet with four transects, Mendolo Wetan Hamlet with two transects, and Krandegan Hamlet with one transect. Data collection on javan slow loris in Mendolo Forest began at 7:30 p.m. to 12 a.m.  We identified 8 individuals exhibiting semi-solitary behavior. Javan slow loris in Mendolo Forest are distributed across 3 hamlets, with 3 individuals in Sawahan Hamlet, 4 individuals in Mendolo Kulon Hamlet, and 1 individual in Krandegan Hamlet. The population density of Javan slow loris in Mendolo Forest is 18.35 individuals/km², with the highest density found in Krandegan Hamlet at 33.3 individuals/km² and the lowest in Mendolo Wetan Hamlet at 0 individuals/km². The estimated population of Javan slow loris in Mendolo Forest is 21.9 individuals. These findings provide crucial baseline data for conservation management of Javan slow loris populations in Java.

Keywords:

Distribution; Nocturnal; Nycticebus javanicus; Primate

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How to Cite

Saputra, M. Y., Nayasilana, I. N., Masyithoh, G., & Setiawan, A. (2025). Javan Slow Loris Population and Ecology at a New Site: Mendolo Forest, Central Java, Indonesia. Research in Ecology, 7(4), 268–279. https://doi.org/10.30564/re.v7i4.9801

Issue

Vol. 7, Iss. 4 (October 2025)(in progress)

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Article

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Copyright © 2025 Muhammad Yoga Saputra, Ike Nurjuita Nayasilana, Galuh Masyithoh, Arif Setiawan

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This is an open access article under the Creative Commons Attribution-NonCommercial 4.0 International (CC BY-NC 4.0) License.

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