How do European shags differ from cormorants in terms of behavior?

European shags (Phalacrocorax aristotelis) and cormorants (family Phalacrocoracidae) are closely related seabirds, but they exhibit notable behavioral differences. European shags are typically more solitary than cormorants, often being found alone or in small groups, especially when foraging. They are also known for their agility in the water, diving quickly to catch fish; they tend to dive deeply and for longer periods compared to the more buoyant cormorants, which often stay on the surface longer and dive in larger, more social groups.

Behaviorally, cormorants engage in more conspicuous social behaviors, often seen in larger colonies during breeding seasons, where they display complex courtship rituals and nest-building activities. In contrast, European shags may nest in smaller, less dense colonies, which can lead to a more aggressive territoriality. Additionally, after diving, cormorants are known for their habit of spreading their wings to dry, while shags also engage in this behavior but usually do so more discreetly. Overall, these differences in social structure, foraging style, and post-feeding behavior highlight the distinct ecological niches these birds occupy despite their similarities.