Morphometric Analysis of Crocodylus novaeguineae from the Fly River Drainage, Papua New Guinea

Abstract

Formulae for predicting snout-vent length from 17 other body measurements and vice versa were derived from data collected on 1073 wild Crocodylus novaeguineae. Equations for predicting live body attributes from dried skulls also are presented. Relative growth and general growth form are described. A 1:1 sex ratio was found for animals between 50 and 167 cm snout-vent length (SVL). Current laws in Papua New Guinea are based on size criteria and protect wild breeding males. However, the laws do not take into account the smaller breeding size of females and thus subject about 36% of adult females to legal hunting mortality. Of all girth-related measures, neck girth was found to be the best predictor of commercial value. New Guinea crocodiles have shorter tails, longer trunks and wider hind feet than saltwater crocodiles, C. porosus; these differences may be related to ecological niche and habitat separation in Papua New Guinea. The morphological characteristics of New Guinea crocodiles better adapt them for life in marshes and swamps, while those of C. porosus better suit them for life in large, open rivers and estuaries.