AAAS: "Crocodiles are alarmingly attuned to the cries of human infants." Infants across the animal kingdom cry out to their parents when they need something. But others may be listening. "Nile crocodiles are uniquely sensitive to the wails of distressed primate babies, according to a new study—and the more anxious the cry, the more interested the crocs become." Nicolas Grimault, a bioacoustician at the University of Lyon, and colleagues visited a zoo in Agadir, Morocco, that houses more than 300 Nile crocodiles (Crocodylus niloticus)—a predator particularly well suited to hunting primates and other mammals. They installed loudspeakers alongside 4 ponds. "The speakers blared out a series of cries from chimpanzee (Pan troglodytes), bonobo (P. paniscus), and human infants, captured in a variety of situations in order to document a wide range of emotion." Many of the crocs, both male + female, responded by rapidly approaching the sound source + sometimes even biting the speakers. "Crocs were more likely to respond to recordings with acoustic features known to correlate to highly upset infants such as disharmony, noise bursts, and uneven tones reminiscent of radio static." Human volunteers assessed cries by pitch, but crocs were even more adept at using alternative acoustic clues like disharmony and noise bursts. Responding to a dinner bell, a remarkable evolutionary adaptation.
#crocodile #hunting #evolutionarybiology