Geographic variation in reproductive traits and trade-offs between size and number of eggs of the Chinese cobra (Naja atra)

摘要: We collected gravid Chinese cobras (Naja atra) from one island (Dinghai) and three mainland (Yiwu, Lishui Quanzhou) populations in south-eastern China to study geographical variation female reproductive traits the trade-off between size number of eggs. then conducted an common experiment on two four further identify factors contributing observed trade-offs. The mean (snout–vent length) smallest five females increased with increasing latitude. Oviposition occurred late June early August, warmer localities laying eggs earlier than those colder localities. Maternal was a major determinant investment all populations, larger producing not only more but also Clutch variable egg within among populations. clutch size, mass post-oviposition body condition simple consequence maternal because interpopulation differences these were still evident when influence removed. upper limit likely be set by space availability population, resource Trade-offs detected that had clutches for their having smaller Egg at any given level relative fecundity differed primarily rather availability. Except timing date oviposition females, other examined did vary geographically continuous trend. garden experiment, which standardized environmental factors, synchronized oviposition, it modify conclusion drawn field. could attributed effects either proximate or ultimate factors. © 2005 Linnean Society London, Biological Journal Society, 2005, 85, 27–40.