Experiential and hormonal conditions affect squab-egg choice in ring doves (Streptopelia risoria).

Noncycling, progesterone-injected, experienced male ring doves prefer eggs to squabs in a simultaneous squab-egg choice test, while experienced male doves injected with both progesterone and prolactin prefer squabs to eggs. When exogenous prolactin is administered to either naive or experienced male ring doves during the early phase of a normal incubation cycle, squab choice is significantly increased. Squab choice is also significantly increased in incubating doves by 24 hr of exposure to a squab in the home nest. This effect is greater in naive than in experienced doves. Squabs introduced during late incubation have more of a positive effect on squab choice than when introduced during early incubation. It is concluded that intracyclic experience organizes successive behavioral changes within a reproductive cycle and that naive doves are more affected by some changes in intracyclic events than are experienced doves.