Vocal dialects and their implications for bird reintroductions

Abstract

Parrot species are a common target of animal trafficking, and the animals recovered from anti-trafficking operations are generally reintroduced into nature. However, these reintroductions usually fail to consider geographical vocal differences that are known to be present in some Parrot species. We investigated patterns of geographical variations in Eupsittula cactorum vocalizations and used those data to infer the geographical origins of recovered birds and thus predict the most appropriate reintroduction sites. We recorded four wild populations in northeastern Brazil (between the western region of Rio Grande do Norte State and northeastern Ceará State), and three groups of captive individuals seized from traffickers. We considered seven acoustic parameters to classify the flight calls of the different native populations and used a multinomial model to classify the recovered animals according to the native populations sampled. Our results indicated the existence of geographical dialects. Individual birds had been released in Quixadá, where local calls are acoustically distinct. Acoustical parameters can provide important clues about the origins of captured individuals as well as reduce acoustical contrasts between released individuals and native populations. The application of this methodology could potentially improve the efficacy of reintroduction efforts, by reducing vocal distances between released individuals and the native population.

Keywords

• Bioacoustics
• Bird reintroductions
• Geographical dialects
• Illegal wildlife trade
• Animal trafficking
• Conservation