Wild monk parakeets have unique 鈥渧oice-prints鈥� that may help them recognise individuals within the flock.
Though select species like humans and bottlenose dolphins (Tursiops truncatus) have vocalisations specific to single individuals, many animals sound indistinguishable from their peers. Even birds that rely on a variety of call types to communicate different intentions tend to sound similar to each other.
鈥淚t鈥檚 hard to think of three groups more [evolutionarily] separated 鈥� dolphins and humans and parrots,鈥� says at the University of Texas Rio Grande Valley, who was not involved in the work. But most people would agree that all three of these animals are very complex communicators, he says.
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For instance, monk parakeets (Myiopsitta monachus), a species of small parrot native to South America, . But whether individual birds have unique voices .
To investigate, researchers at the Max Planck Institute in Germany recorded more than 5500 vocalisations from 229 wild monk parakeets living as an introduced species in Barcelona, Spain. Each parakeet had a so that researchers could link each bird with its calls.
They analysed the acoustic features of five call types using computer simulations, and found monk parakeets have distinct voice-prints in two of them: contact calls and 鈥渢rruup鈥� calls. Contact calls are short exclamations to notify other parakeets of the caller鈥檚 arrival. 鈥淭rruup鈥� calls rise in their tone at the end of the call, and their function is still unknown. As keen vocal learners, parakeets probably develop their calls at a young age by mimicking nearby adults, but they seem to retain their unique 鈥渧oices鈥�.
鈥淭he question is, why is it important to be able to recognise an individual?鈥� says at Cornell University in New York. Dhondt says the work could have benefited from also exploring how and why these voice-prints may have evolved.
Knowing friend from foe is likely a boon in the birds鈥� hierarchical society, says Berg. 鈥淭he more [birds] can figure out from sound, the better off [they] are. Information is power,鈥� he says.
Journal reference: bioRxiv,
