Life-history of masked water snakes (Homalopsis buccata) in Java: implications for the sustainability of harvesting

Evy Arida; Noor Laina Maireda; Alamsyah Elang Nusa Herlambang; Mumpuni; Awal Riyanto; Amir Hamidy; Richard Shine; Daniel J. D. Natusch

doi:10.1071/WR23118

RESEARCH ARTICLE (Open Access)

Life-history of masked water snakes (Homalopsis buccata) in Java: implications for the sustainability of harvesting

Evy Arida ^A ^B , Noor Laina Maireda ^C , Alamsyah Elang Nusa Herlambang ^B ^D , Mumpuni ^B ^D , Awal Riyanto ^B ^D , Amir Hamidy

^B ^D , Richard Shine ^B ^E and Daniel J. D. Natusch

^B ^E ^*

+ Author Affiliations

- Author Affiliations

^A Research Center for Applied Zoology, Organization for Research of Life Sciences and Environment, Research and Innovation Agency of Indonesia, Gd. Widyasatwaloka, KST Soekarno, Jl. Raya Jakarta-Bogor Km 46, Cibinong, West Java.

^B IUCN SSC Snake Specialist Group, 1/26 Florence Street, Cairns, Qld, 4870, Australia.

^C Indonesian Herpetological Society (Penggalang Herpetologi Indonesia/PHI), Departemen KSDHE, Fakultas Kehutanan IPB, Jl. Ulin, Kampus IPB Dramaga, Bogor 16680, West Java.

^D Laboratory of Herpetology, Museum Zoologicum Bogoriense, Research Center for Biosystematics and Evolution, Organization for Research of Life Sciences and Environment, Research and Innovation Agency of Indonesia, Gd. Widyasatwaloka, KST Soekarno, Jl. Raya Jakarta-Bogor Km 46, Cibinong, West Java.

^E School of Natural Sciences, Macquarie University, Sydney, NSW 2109, Australia.

^* Correspondence to: d.natusch@epicbiodiversity.com

Handling Editor: Jonathan Webb

Wildlife Research 51, WR23118 https://doi.org/10.1071/WR23118

Submitted: 11 September 2023 Accepted: 13 March 2024 Published: 8 April 2024

© 2024 The Author(s) (or their employer(s)). Published by CSIRO Publishing. This is an open access article distributed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License (CC BY-NC-ND)

Abstract

Context

Masked water snakes (Homalopsis buccata, Homalopsidae) thrive in the muddy edges of agricultural ponds and canals in densely populated areas of West Java, Indonesia, and are harvested by local farmers to protect fish stocks and to provide meat, skins, and medicines for commercial use.

Aims

Here, we aimed to quantify sexual dimorphism and reproductive biology of H. buccata, so as to deepen our knowledge of the species’ inherent ability to withstand commercial harvests.

Methods

We examined carcasses of 4286 snakes at six processing sites to quantify biological attributes (e.g. sexual dimorphism in body size and shape, seasonality of reproduction, fecundity, reproductive frequency), with emphasis on traits that affect the ability of snake populations to withstand this intensive harvesting.

Key results

The snakes we examined were primarily adults (<1% juvenile), with approximately equal numbers of males and females except in January (when females comprised >90% of specimens). Females grow larger than males, and they are more heavy-bodied but shorter-tailed than are males of the same snout–vent length. Reproduction is seasonal in both sexes, with testis volumes decreasing to a minimum over the period August to November (late dry season) when most adult-size females were gravid. Litter sizes ranged from 1 to 37 (mean 12), increasing with maternal body size, with ~75% of females reproducing each year.

Conclusions

On the basis of these results, we infer that the life history of H. buccata (viviparity, high fecundity, frequent reproduction, rapid maturation) renders it inherently resilient to harvesting, especially because that offtake is based on males as well as females. Because a lack of sustainability is evident only in hindsight, regular monitoring of the trade could assure that any problems are detected rapidly.

Implications

To further buffer these populations from the impact of harvest, hunting could be restricted during January (a time when gravid females are disproportionately vulnerable) and the largest snakes (females, with high fecundity and reproductive frequency) could be excluded from harvests.

Keywords: CITES non-detriment findings, harvest, Homalopsinae, Indonesia, offtake, population monitoring, puff-faced water snake, wildlife trade.

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