Immune defense involves inflammatory reactions in which immune cells produce reactive oxygen species (ROS) to fight pathogens. ROS may however cause damage to the host if they are not balanced by antioxidant defenses. Therefore, one should expect individuals undergoing an immune reaction to use antioxidants to prevent oxidative stress. Antioxidants are vital compounds that provide important pro...

Maternal effects provide a mechanism to adapt offspring phenotype and optimize the mother's fitness to current environmental conditions. Transferring steroids to the yolk is one way mothers can translate environmental information into potential adaptive signals for offspring. However, maternally-derived hormones might also have adverse effects for offspring. For example, recent data in zebra fi...

Subsongs are vocal trials uttered by young birds to practice songs. Among songbirds, subsongs are displayed by individuals in their first year of life. Studies on Zebra Finches Poephila guttata suggest that the juveniles learn their songs from a vocal tutor, their father. In this study we examine the subsongs in six captive-born Meyer's Parrots Poicephalus meyeri, from fledging time to weaning....