From Bill Bucolo:

Re: “Mafia” behavior noted in birds (March 5): So, accepter warblers have more offspring, but I wonder if the progeny of rejecter warblers is a hardier, more independent and stronger bird than that of accepters? And if that particular strain of offspring is more likely to also reject parasitic cowbird eggs? And if fighting warblers beget warblers more inclined to fight, I wonder if being the strongest warbler is best after all, since their more combative presence may purturb combative cowbirds more, resulting in even more ransacked nests? I would like to think that whether with people or birds, those who stand up to bullies (or mafia) pay a dear price, but really win in the end.