The world´s largest choir in words and images. South America boasts the highest avian diversity and endemism in the world. Until recently, there had been no single field guide which would cover all the passerines of the "bird continent". In 2009, a field guide by R. S. Ridgely (authoritative text) and G. Tudor (meticulously detailed plates) finally filled the long-standing gap. Here, we present a review of this excellent field guide and put it into the context of previously published literature on South American birds.
Why does a cuckoo chick kill its nestmates? Cuckoo nestling evicting host eggs and chicks provides one of the most impressive sights in the nature. Recent research shows that evicting host progeny is surprisingly costly for the young cuckoo in terms of growth and risks of self-eviction. Although being costly, the eviction instinct is still adaptive because alternative strategies (host clutch or brood is removed by the female cuckoo and/or outcompeted later by a larger cuckoo chick) are even more costly (clutch desertion and/or impaired growth, survival and fledging of the parasite chick caused by severe competition with host chicks).