Food Restriction During Development Impairs Reproductive Success but not Ornamentation in Zebra Finches

Stress during development can elicit lifelong changes to an organism. However, whether these changes are beneficial or detrimental can only be determined by their effect on fitness outcomes. Furthermore, the effect of severe, chronic food restriction on the development of ornamentation, which can influence attractiveness, still needs to be explored. In this study, zebra finches (Taeniopygia castanotis) were exposed to either an ad libitum (control) diet or a 40% restricted (food-restricted) diet throughout postnatal development. Pictures of beaks and cheek patches were captured throughout the juvenile period and into adulthood to measure the development of secondary sexual characteristics. In adulthood, females were paired with nonexperimental males to measure reproductive success. There was no effect of treatment on beak color development or final beak color, but food-restricted males developed cheek patches slower and had more asymmetry during cheek patch development. However, food restriction did not impact the final cheek patch color or size. Food-restricted females were found to have lower reproductive success than control females. These results suggest that while cheek patch ornamentation can experience 'catch-up growth', and beak and cheek patch color do not reflect past developmental stress exposure, developmental food restriction impairs female reproductive success in a short-lived passerine.