Sexual dimorphism and reproductive biology of commercially harvested Indonesian Spitting Cobras (Naja sputatrix, Elapidae) from West Java

Indonesian Spitting Cobras (Naja sputatrix) are abundant in agroecosystems on Java and adjacent islands, are a significant cause of snakebite, and are harvested commercially for their skins and meat. We examined carcasses of 159 snakes at processing facilities in and around the city of Cirebon in West Java. Males outnumbered females, and most specimens were adult. Males were more heavy-bodied than females of the same body length, and had longer tails. Gonadal size and condition and energy (fatbody) storage was seasonal, with females in our sample containing oviductal eggs during September–October and in February; we infer wet-season oviposition, although no data were available for December–January. Clutch size averaged 14, ranging from 6 to 23 eggs. Comparison of this sample with one taken 25 years previously in Central Java, using the same methods, revealed a similarity in male-biased sex ratio and the numerical preponderance of adults. Snakes of both sexes averaged larger in the current sample from West Java than in the earlier study from Central Java, likely reflecting geographic variation rather than any impacts of commercial harvesting over the intervening period. Exploitation of agricultural habitats, broad diets, high fecundity and formidable venom render this species resilient to current levels of commercial offtake.