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Gravid females of viviparous snake species maintain higher and less variable body temperatures (Tb) than their nongravid conspecifics. Although the benefits of higher and less variable Tb's, mainly accelerated embryogenesis resulting in earlier parturition/oviposition, should also apply to oviparous snake species, few studies have adequately addressed this question. To test whether gravid and nongravid females of oviparous snakes exhibit different thermoregulatory behaviour, I surgically implanted temperature-sensitive radiotransmitters into 14 female (six gravid, eight nongravid) eastern fox snakes ('Elaphe gloydi') and placed them in an outdoor enclosure. Snake Tb's and environmental temperatures from thermal models were measured at 1-h intervals over 8 days (N = 146). Gravid females did not maintain higher and less variable Tb's than nongravid females, nor did they exhibit obvious differences in overt thermoregulatory behaviour. The combination of a thermally "benign" environment, along with a short period of egg retention, relative to viviparous species, may render careful thermoregulation unnecessary in this population. |
