Complex sentence: They are gregarious and will feed in large groups at night and during dawn and dusk as well as during the day; this crepuscular and nocturnal behaviour is more common during the breeding season.
Split into simpler sentences: They are gregarious and will feed in large groups. The feed at night and during dawn and dusk as well as during the day, this crepuscular and nocturnal behaviour is more common during the breeding season.