Reproductive Ecology of the Orinoco Crocodile (Crocodylus intermedius) in Venezuela. i. Nesting Ecology and Egg and Clutch Relationships

Abstract

The reproductive ecology of wild and captive Orinoco crocodiles was studied in the llanos of Venezuela. Nesting occurs during the early dry season and eggs hatch during the initial rise in water level at the beginning of the wet season. In the Capanaparo River hole-type nests are situated in elevated, sandy substrates (eroded river banks - 54%, beaches - 46%) along riverbanks. The peak nest density ranged from 0.24 to 0.36 nests/km, but the distribution of nests was clumped, reflecting the dry-season grouping of females. Individual females reused nesting sites and the estimated reproductive frequency was high (ca. 80%). Natural nest depredation was not encountered, but a large percentage of the nests are collected by Indians for subsistence purposes. Average female TL in the wild was 306 cm. Females mature at a size of 250 cm TL and reach a maximum size of 360 cm TL. Among captive crocodiles, egg viability is positively correlated, and date of oviposition is negatively correlated with female size. Egg size, clutch size, and clutch mass are all positively correlated with female size, but when female size s is accounted for, no tradeoff between clutch size and egg size was found.