{"fact":"Crows from Switzerland, where they typically don't help raise young, surprised researchers by staying and helping in Spanish crow families when they were raised there.","context":"Here we show that offspring of non-cooperative carrion crows from Switzerland will remain on the natal territory and express helping behaviour when raised in a cooperative population in Spain...five out of six transplanted juveniles delayed dispersal, and two of those became helpers in the following breeding season.","source":"Vittorio Baglione; Daniela Canestrari; José M. Marcos; Michael Griesser; Jan Ekman, History, environment and social behaviour: experimentally induced cooperative breeding in the carrion crow, 10.1098/rspb.2002.2016","index":48}