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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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References

LITERATURE CITED

Bayliss, P., Webb, G. J. W., Whitehead, P. J., Dempsey, K. & Smith, A. 1986. Estimating the abundance of saltwater crocodiles, Crocodylus porosus Schneider, in tidal wetlands of the Northern Territory: a mark recapture experiment to correct spotlight counts to absolute numbers and the calibration of helicopter and spotlight counts. Australian Wildlife Research 13:309–320.CrossRefGoogle Scholar
Cox, J. & Gombek, F. 1985. A preliminary survey of the crocodile resources in Sarawak, East Malaysia. IUCN/WWF Project Report No. MAL 74/85. World Wildlife Fund Malaysia, Kuala Lumpur.Google Scholar
Inger, R. F. & Chin, P. K. 1962. The freshwater fishes of North Borneo (Monograph). Fieldiana: Zoology No. 45. Chicago.Google Scholar
Jenkins, R. W. G. & Forbes, M. A. 1985. Seasonal variation in abundance and distribution of Crocodylus porosus in the tidal East Alligator River, Northern Australia. In Grigg, G., Shine, R. & Ehman, H. (eds). Biology of Australasian frogs and reptiles. Royal Zoological Society, New South Wales.Google Scholar
Kusuadi, S. 1985. A survey of the status and ecology of the crocodile (Crocodylus porosus) in several rivers in Sabah and Sarawak (in Malay). BSc Thesis, Department of Biology, Universiti Kebangsaan Malaysia, Sabah Campus, Kota Kinabalu, Sabah.Google Scholar
Magnusson, W. E. 1979. Dispersal of hatchling crocodiles Crocodylus porosus (Reptilia, Crocodilidae). Journal of Herpetology 13:227–231.Google Scholar
Magnusson, W. E. & Taylor, J. A. 1981. Growth of juvenile Crocodylus porosus as affected by season of hatching. Journal of Herpetology 15:242–245.Google Scholar
Messel, H. & Vorlicek, G. C. 1986. Population dynamics and status of Crocodylus porosus in the tidal waterways of Northern Australia. Australian Wildlife Research 13:71–111.CrossRefGoogle Scholar
Messel, H., Vorlicek, G. C., Green, W. J. & Onley, I. C. 1981. Surveys of the tidal river systems in the Northern Territory of Australia and their crocodile populations. Monograph No. 1: The Blyth—Cadell river systems study and the status of Crocodylus porosus in tidal waterways of Northern Australia. Methods for analysis and dynamics of a population of C. porosus. Pergamon Press Ltd, Sydney.Google Scholar
Shahrul, A. M. S. 1992. A study of the population structure and feeding ecology of the estuarine crocodile (Crocodylus porosus Schneider) in the Klias River, Sabah (in Malay). BSc Thesis, Department of Biology, Universiti Kebangsaan Malaysia, Sabah Campus, Kota Kinabalu, Sabah.Google Scholar
Stuebing, R., Ismail, G. & Ling, H. C. 1990. The distribution and abundance of the estuarine crocodile (Crocodylus porosus Schneider) in the Klias River, Sabah. Paper presented at the International Conference on Forest Biology and Conservation in Borneo, Kota Kinabalu, Sabah.Google Scholar
Stuebing, R., Ismail, G. & Sallih, K. 1985. The ecology of crocodile attacks in Batang Lupar, Sarawak. Sarawak Museum Journal 55:189–214.Google Scholar
Stuebing, R. & Shahrul, A. M. S. 1992. Population characteristics of the Indo-Pacific crocodile (Crocodylus porosus Schneider) in the Klias River, Sabah. Paper presented at the 11th Working Meeting of the IUCN-SSC, Crocodile Specialist Group, Victoria Falls, Zimbabwe.Google Scholar
Stuebing, R., Shahrul, A. M. S., Mahedi, A. & Lawrentius, N. A. 1993. Conservation, management and farming of crocodiles in Sabah. Paper presented at the 2nd Regional Conference of the IUCN-SSC, Crocodile Specialist Group, 12–19 03 1993, Darwin, Northern Territory, Australia.Google Scholar
Taylor, J. A. 1979. The foods and feeding habits of subadult Crocodylus porosus Schneider in northern Australia. Australian Wildlife Research 6:347–359.Google Scholar
Taylor, J. A., Webb, G. J. W. & Magnusson, W. E. 1978. Methods of obtaining stomach contents from live crocodilians (Reptilia: Crocodilidae). Journal of Herpetology 12:415–417.CrossRefGoogle Scholar
Webb, G. J. W., Hollis, G. J. & Manolis, S. C. 1991. Feeding, growth and food convresion rates of wild juvenile saltwater crocodiles (Crocodylus porosus). Journal of Herpetology 25:462–473.Google Scholar
Webb, G. J. W., Manolis, S. C. & Buckworth, R. 1982. Crocodylus johnstoni in the McKinlay River area, Northern Territory. I. Variation in the diet, and a new method of assessing the relative importance of prey. Australian Journal of Zoology 30:877–879.Google Scholar
Webb, G. J. W., Manolis, S. C. & Sak, G. C. 1984. Cloacal sexing of hatchling crocodiles. Australia Wildlife Research 11:201–202.Google Scholar
Webb, G. J. W. & Messel, H. 1978. Movement and dispersal patterns of Crocodylus porosus in some rivers of Arnhem Land, northern Australia. Australian Wildlife Research 5:263–283.CrossRefGoogle Scholar
Webb, G. J. W. & Messel, H. 1979. Wariness in Crocodylus porosus (Reptilia: Crocodilidae). Australian Wildlife Research 6:227–234.Google Scholar
Webb, G. J. W., Messel, H. & Magnusson, W. E. 1977. The nesting biology of Crocodylus porous in Arnherh Land, northern Australia. Copeia 2:238–249.Google Scholar
Whitaker, R. 1984. A preliminary survey of crocodiles in Sabah, East Malaysia. IUCN/WWF Project No. 3127. World Wildlife Fund Malaysia, Kuala Lumpur.Google Scholar