Fortune favours the aggressive: territory quality and behavioural syndromes in song sparrows, Melospiza melodia

► We examined the relationship between territory quality (nest success) and an aggression-boldness syndrome in song sparrows.► Historical (2000-2007) clutch size and survival were significantly clustered. ► Territorial aggression was correlated with historical clutch size but not survival. Boldness was not correlated with either historical clutch size or survival.