Slow flight is extremely energetically costly per unit time, yet highly important for takeoff and survival. However, at slow speeds it is presently thought that most birds do not produce beneficial aerodynamic forces during the entire wingbeat: instead they fold or flex their wings during upstroke, prompting the long-standing prediction that the upstroke produces trivial forces. There is increa...

In vertebrates, antioxidant defences comprise a mixture of endogenously produced components and exogenously obtained antioxidants that are derived mostly from the diet. It has been suggested that early-life micronutritional conditions might influence the way in which the antioxidant defence system operates, which could enable individuals to adjust the activity of the endogenous and exogenous co...

Hormonal systems have long been thought to play an important role in stimulating the onset of parental behavior, a critical component of reproductive success in a variety of taxa. Elevations in the peptide hormone prolactin (PRL) have been repeatedly positively correlated with the onset and maintenance of parental care across vertebrate species. A causal role for PRL in parental care has been e...