By Susan Milius
The first known case among nonhuman vertebrates of so-called desperado aggression–relentless attacks against an overwhelming force–may come from the underling chick in nests of brown boobies.
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An unusual experiment that tucked junior chicks into the nests of a related species let the youngsters live long enough to show their stuff, says Hugh Drummond of the Universidad Nacional Autónoma de México in Mexico City. These chicks ferociously attacked their older foster sibs, and almost half of the relocated chicks became “uncontrollably aggressive,” Drummond and his colleagues report in an upcoming Behavioral Ecology and Sociobiology.