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Diet, growth and movements of juvenile crocodiles Crocodylus porosus Schneider in the Klias River, Sabah, Malaysia

Published online by Cambridge University Press:  10 July 2009

Shahrul Anuar Mohd Sah  and
Robert B. Stuebing
Shahrul Anuar Mohd Sah
Affiliation:
School of Biological Science, Universiti Sains Malaysia, 11800 Penang, Malaysia
Robert B. Stuebing
Affiliation:
Biology Department, Universiti Kebangsaan Malaysia, Sabah Campus, 88996 Kota Kinabalu, Sabah, Malaysia
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Abstract

A total of 14 spotlight surveys were carried out from January 1992 to February 1993 along 37 km of the Klias River in north-western Sabah, Malaysia. Surveys were at low tide between 1900 and 0600 h from a survey boat at 15 km h−1 by two observers. A total of 221 sightings were made, which varied between 2 and 29 per survey (mean 15.8). A total of 55 juvenile crocodiles were captured, with 16 recaptures. Calculated density was 0.9–1.8 individuals km−1, while the estimated crocodile population was 46.1 ± 10.2 (SD) for the survey area. Percentage sightings according to total length were: 42% ≤0.5 m; 40% >0.5-≤1.0 m; 5% > 1.0-≤3.0; and 13% eyes only. Recapture of 16 tagged juveniles suggested that hatchlings ≤0.5 m total length remained within >0.5 km of their release point for at least one month, and juveniles 0.5-≤1.0 m more than one year. Hatchlings had growth rates between 0.01 and 0.08 cm d−1 and 0.3 and 1.5 g d−1, while larger juveniles grew at least 0.11 cm d−1 and 2.7–2.9 g d−1. Stomachs of hatchlings and juveniles contained crabs (Ocypodidae), prawns (Atyidae), insects and small fish (Hemiramphidae). Relatively large numbers of juvenile Crocodylus porosus (82.4%) in the Klias River suggests that the area, though under hunting pressure, is desirable as a site for the conservation of C. porosus in the Sabah.

Keywords

crocodileCrocodylus porosusdispersalHemiramphidaejuvenileprawnsSabahtropical ecology
Type
Research Article
Information
Journal of Tropical Ecology , Volume 12 , Issue 5 , September 1996 , pp. 651 - 662
Copyright
Copyright © Cambridge University Press 1996

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