Burrow Distribution, Size and Chemical Composition of the African Dwarf Crocodile (Osteolaemus Tetraspis) of the Niger Delta Nigeria

Abstract

Studies on the African dwarf crocodile in the Niger Delta mangrove are limited because of lack of data. This study was a chance event which discovered some burrows in cleared mangrove forest. Based on the nocturnal life and the difficulty in tracking and capturing the crocodiles their burrows were studies to determine their numbers and size differences. Furthermore, distances of the burrow to the river and the burrow soil chemistry were investigated to determine the impact of anthropogenic activities on the nascent community. The diameter of the burrows and the distances of the burrow to water were measured and the soil samples collected from each burrow to determine the total hydrocarbon content (THC) and heavy metals. In all 105 burrows were counted along a 90 m transect and results reveals that more burrows were medium sized (n =69; size range: 9-15 cm), followed by large (n = 24; size range: 16-23 cm) and small (n = 12; size range: 0-8 cm) sizes. The soil chemistry revealed that there was no significant difference between burrows in THC and heavy metal concentration (P>0.05). However, burrows close to the river had higher chemical concentration than inner burrows. The order of chemical concentration is  HC>Chromuim>Copper>Cadmium>Lead. Again there was no correlation between distance from water and diameter of burrow ((F 1, 103 = 0.33, P = 0.56). The smaller burrows were the closest to the river (1.43?ñ0.10 m) followed by the large (1.59?ñ0.11 m) and the medium (1.59?ñ0.11) burrows. Proximity to the water provides quick access to the river for hunting and safety for predators. The result implies that crocodile population is endangered by pollution, bush

Keywords

alligator burrow conservation crocodile Niger Delta sand mining.

  • Research Identity (RIN)

  • License

    Attribution 2.0 Generic (CC BY 2.0)

  • Language & Pages

    English, Array-Array

  • Classification

    NA