Crocodile Survey Along Some Major Rivers
Based on the data obtained through discontinuous survey and spotting count from 1992 until 1997, Sarawak Mangrove, Batang Lingga/Batang Lupar and Sg. Sarawak were found to have a recovering population status of crocodile of Crodoylus porosus species at a respective density of 1.90 individual/km, 0.40 individuals/km, 0.90 individuals/km and 0.15 individuals/km. This was in comparison to the previous information obtained about fifteen years ago by Cox and Gombek (1985) who found that crocodiles in Sarawak were badly exploited and were facing a dark future. In addition to the taboo to kill and consume the species among most of the Sarawak indigenous people, the introduction and implementation of the Sarawak Forest Department Wildlife Protection Ordinance (1990) is thought to have contributed to the recovery of the crocodile population after having been badly depleted during the Brooke era.
The survey has also indicated that some rivers within the Sarawak Mangrove areas and Batang Lupar as well as its main tributary of Batang Lingga, where fatal attacks on human being often occurred previously, were housing breeding population of Crocodylus porosus while Sg. Ensengei was inhabiting that of Tomistoma schlegelli. Though found more abundantly in Sarawak Mangrove compared to elsewhere in Sarawak, about 77% of the crocodile attacks on mankind occurred along Batang Lupar (including its major tributaries of Batang Lingga and Batang Seterap). Higher preference by the predators to establish their territories and greater human activities along the river could possibly be the explanation as to why more attacks occurred within the area in comparison to rivers elsewhere in Sarawak.
As along as mankind is using rivers, it is impossible to prevent crocodile attack on humans but the frequency of the attack could possibly be reduced by culling and capturing the potential man eaters, identifying the potential crocodile territories and by monitoring changes in environmental parameters, such as salinity, water temperature, breeding season and rainfall. It is believed that these parameters could stimulate the attack.