| Titre : | Vocal mimicry in African Cossypha robin chats |
| Auteurs : | J. W. H. Ferguson, Auteur ; A. van Zyl, Auteur ; K. Delport, Auteur |
| Type de document : | Article |
| Dans : | Journal of Ornithology (143(3) JUL 2002) |
| Article en page(s) : | 319-330 |
| Langues: | Anglais |
| Résumé : | Four hypotheses were tested for explaining interspecific mimicry observed in African Cossypha robin-chats. (1) The five robin species imitate similar models. (2) Natal Robin imitations reflect the acoustic environment within their habitat. (3) Natal Robins imitate competitor species. (4) Natal Robins imitate predators and brood parasites. The study included analysis of extensive collections of sound recording of these five species, as well as recordings of the Natal Robin Cossypha natalensis obtained in the field. The robin species mimicked different species groups, in accordance with their acoustic environment. This also applied to different Natal Robin populations. Only hypothesis (2) was confirmed, the others being refuted. It appears that bird species with simple calls have a greater probability of being mimicked. Our results were consistent with Hartshorne's prediction that song versatility increases with song duration. |



