Sex steroids and postreproductive refractoriness in the lizard, Podarcis s.sicula

The evolution of sex steroids in the plasma and gonads of the lizard Podarcis s. sicula during the postreproductive period shows that these hormones could be involved in determining refractoriness. In the male, during this phase, the oestradiol could lower the hypothala‐mo‐hypophyseal system through a negative feed‐back. In the female a similar role could be assigned to progesterone.