Data from: Decreased food intake as a fecundity-dependent cost of reproduction in keelback snakes (Tropidonophis mairii, Colubridae)

The physical burden of pregnancy may render females slower and less able
to evade predation, favouring a reduction in feeding in order to avoid a
reduction in survivorship. Life-history theory predicts that an organism’s
optimal level of investment into reproduction depends upon whether or not
the associated “costs” (such as a decrease in rate of feeding) increase
with higher fecundity. Anorexia during pregnancy is widespread among
snakes, but there are few field data on fecundity-dependence of such
costs. Over a 23-year period, we recorded reproductive condition and
feeding status (based on palpation and production of faeces) for 3778
captures of free-ranging female natricine colubrid snakes (keelbacks,
Tropidonophis mairii) in tropical Australia. Pregnancy reduced feeding
rates, and that decrease was greatest for females with higher reproductive
investment (clutch mass relative to maternal mass). Our long-term data
provide the first clear-cut evidence of fecundity-dependent costs of
reproduction in free-ranging snakes.