Fisher-Assisted Records of Silvery Langurs (Trachypithecus cristatus) in an Urban Mangrove Fragment, Medan Labuhan, North Sumatra
DOI:
https://doi.org/10.32734/jsi.v9i02.24997Keywords:
Coastal Mangrove, Fishermen, Indonesia, Local Sighting, Primate OccurrenceAbstract
Primate populations inhabiting human-modified landscapes continue to face threats to their persistence and long-term viability. Local studies have therefore been conducted across different regions to document the effects of habitat modification on these populations. Small mangrove patches within industrial coastal areas are seldom included in primate surveys. We examined the occurrence of the silvery langurs (Trachypithecus cristatus) in an isolated mangrove patch near the Belawan International Container Terminal, Medan Labuhan, North Sumatra. Three boat surveys were completed in August 2024 with assistance from local fishers. Direct observations were recorded during each trip, and semi-structured conversations documented local ecological knowledge (LEK). Nine sightings were made, with group sizes from one to fourteen individuals; infants were present in two sightings. When approached by boat, the animals generally moved away from the channel and into denser vegetation. The fishers' descriptions of conspicuous morphological features and commonly eaten plants broadly agreed with published accounts, whereas their views of population change differed. Because individuals were not identified and the fieldwork comprised only three targeted surveys, the records establish occurrence during the survey month but do not confirm residency, abundance, or population trend. The observations provide a starting point for longer standardized surveys of silvery langurs and their mangrove habitat in Medan Labuhan.
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