Data from: Maternal corticosterone exposure has trans-generational effects on grand-offspring

The hormone fluctuations that an animal experiences during ovulation can have life-long effects on developing offspring. These hormones may act as an adaptive mechanism, allowing offspring to be ‘pre-programmed’ to survive in an unstable environment. Here, we used a trans-generational approach to examine the effects of elevated maternal corticosterone (CORT) on the future reproductive success of female offspring. We show that female zebra finches (Taeniopygia guttata) exposed to embryonic CORT produce daughters that have equal reproductive success (clutch sizes, fertility, hatching success) compared to the daughters produced from untreated mothers, but their offspring had accelerated post-hatching growth rates and were significantly heavier by nutritional independence. Although there was no significant effect on primary offspring sex ratio, females from CORT-treated mothers produced significantly female-biased clutches by nutritional independence. To our knowledge, this is the first record of a trans-generational sex ratio bias in response to elevated maternal CORT in any avian species.