Distinctive pheomelanin-based plumage colouration in juvenile birds has been proposed as a signal of immaturity to avoid aggression by older conspecifics, but recent findings suggest a detoxifying...

The lesser black backed gull Larus fuscus is now the second most abundant wintering waterbird in Andalusia, and has increased in numbers in recent years. Fuente de Piedra, the biggest shallow lake...

Aggressive sibling competition for parental food resources is relatively infrequent in animals but highly prevalent and extreme among certain bird families, particularly accipitrid raptors...

Ex situ programmes have become critical for improving the conservation of many threatened species, as they establish backup populations and provide individuals for reintroduction and reinforcement...

Competitive environments promote high testosterone levels, oxidative stress and, consequently, impair cellular homeostasis. The regulation of genes involved in the synthesis of the pigment...