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On a collection of reptiles from Sarawak

From Munshipedia, the MBRAS digital historical encyclopedia

On a collection of reptiles from Sarawak

Emmett R. Dunn published this brief taxonomic note in 1923, reporting on a reptile collection assembled by J. C. Moulton and Harrison W. Smith in the upper Baram River region of north-western Sarawak during September to November 1920. The paper documents 57 lizard specimens (13 species) and 53 snake specimens (24 species), and formally describes three new snake species from the collection. It stands as one of the earliest faunal surveys of the Baram basin, a region then still largely unexplored by Western naturalists.

Summary

The collection was made in the upper waters of the Baram River, a remote area of north-western Sarawak that at the time had received little systematic zoological attention. Dunn’s notes are organized into two sections: Lacertilia and Ophidia. The lizard assemblage, comprising 57 specimens across 13 species, represents roughly one-seventh of the total lizard species then recorded for Borneo (p. 2). Among the lizards, Dunn highlights the occurrence of Gehyra beebei, a gecko previously known from a single specimen collected at Kapit in 1910, now represented by four individuals from Long Akar and Long Sap (p. 2). Two agamid species—Draco cristatellus and D. formosus—are noted as rarities for the region (p. 2).

The snake section proved more significant. Of 53 specimens representing 24 species, all belong to the Colubridae; 23 fall into the harmless subfamilies Colubrinae (18 species) and Dipsadomorphinae (5 species), and only one specimen is venomous, Doliophis bivirgatus (p. 3). Moulton’s field note records that a fine Hamadryad measuring 9 feet was taken at Lio Matu but not sent for identification, and that only two poisonous snakes were captured out of a total of 54, which he interprets as evidence of the general harmlessness of Bornean snakes (p. 3). Two rare colubrine species are highlighted: Natrix flavifrons, previously known only from Mount Kinabalu and Mt. Penrissen, and Calamaria lowi, apparently confined to this part of Sarawak (p. 3).

The three new species—Natrix frenata sp. n., Calamaria moultoni sp. n., and Calamaria smithi sp. n.—are each represented by a single specimen, which were transferred to the British Museum at the request of the Director of the Raffles Museum, Singapore (p. 3). Dunn provides full morphometric and scalation data for each, discussing their affinities to known congeners (pp. 3–5).

Key Findings

  • The collection yielded three new snake species: Natrix frenata sp. n. (from Mt. Murud, 2,000 ft; total length 260 mm, 166 ventrals, 112 subcaudals), Calamaria moultoni sp. n. (from Long Mujan; total length 270 mm, 122 ventrals, 23 subcaudals), and Calamaria smithi sp. n. (from Long Mujan; total length 103 mm, 142 ventrals, 21 subcaudals) (pp. 3–5).
  • Gehyra beebei, a gecko known since 1910 from a single female at Kapit, was recovered in four specimens (three at Long Akar, one at Long Sap), with head-and-body length 43–52 mm and tail 50 mm (p. 2).
  • Natrix flavifrons, a rare montane species previously recorded only from Mount Kinabalu and Mt. Penrissen, was collected from Lio Matu and Mt. Murud (2,000 ft), extending its known range (p. 3).
  • Calamaria lowi Boulenger appears geographically restricted to the upper Baram region, with eight specimens from Long Mujan and Long Sap (p. 3).
  • Only one venomous snake (Doliophis bivirgatus) was present among 53 snake specimens; Moulton’s field note records a 9-foot Hamadryad (E. melanurus) taken at Lio Matu but not forwarded for identification (p. 3).
  • The lizard assemblage of 57 specimens (13 species) equals approximately one-seventh of the total Bornean lizard fauna then known, including four Draco species, two Gonyocephalus, and Calotes cristatellus (p. 2).

Conclusion

Dunn’s paper establishes the upper Baram River as a zone of notable herpetofaunal richness and endemism, with three new species and multiple range extensions documented from a single collecting season. The low proportion of venomous snakes and the concentration of rare colubrine forms in the flooded riverine habitat at Long Mujan suggest that seasonal flooding creates a distinctive microhabitat supporting specialized faunas. The transfer of all type specimens to the British Museum ensures their long-term availability for future taxonomic revision.

Context

  • The Moulton–Smith collection was made during a period when the Baram River region was under the administrative jurisdiction of the White Rajah’s Sarawak, and the collecting sites (Long Akar, Long Mujan, Long Sap, Lio Matu) correspond to river-mouth settlements along the Baram and its tributaries (p. 2, n. 1).
  • The paper appears in the inaugural volume of the Journal of the Malayan Branch of the Royal Asiatic Society (Vol. 1, No. 1, April 1923), reflecting the Society’s early commitment to publishing primary natural-history research from the Malay Peninsula and Borneo.

References