			Home About us Contact

Begging Calls (begging + call)

Distribution by Scientific Domains

Life Sciences	100%

Selected Abstracts

Begging call matching between a specialist brood parasite and its host: a comparative approach to detect coevolution

BIOLOGICAL JOURNAL OF THE LINNEAN SOCIETY, Issue 1 2009
MICHAEL G. ANDERSON
Studies of avian brood parasite systems have typically investigated the mimicry of host eggs by specialist parasites. Yet, several examples of similarity between host and parasite chick appearance or begging calls suggest that the escalation of host,parasite arms races may also lead to visual or vocal mimicry at the nestling stage. Despite this, there have been no large-scale comparative studies of begging calls to test whether the similarity of host and parasite is greater than predicted by chance or phylogenetic distance within a geographically distinct species assemblage. Using a survey of the begging calls of all native forest passerines in New Zealand, we show that the begging call of the host-specialist shining cuckoo (Chrysococcyx lucidus) is most similar to that of its grey warbler (Gerygone igata) host compared to any of the other species, and that this is unlikely to have occurred by chance. Randomization tests revealed that the incorporation of the shining cuckoo's begging calls into our species-set consistently reduced the phylogenetic signal within cluster trees based on begging call similarity. By contrast, the removal of the grey warbler calls did not reduce the phylogenetic signal in the begging call similarity trees. These two results support a scenario in which coevolution of begging calls has not taken place: the begging call of the host retains its phylogenetic signal, whereas that of the parasite has changed to match that of its host. © 2009 The Linnean Society of London, Biological Journal of the Linnean Society, 2009, 98, 208,216. [source]

Similarity in the begging calls of nestling Red-winged Blackbirds

JOURNAL OF FIELD ORNITHOLOGY, Issue 3 2008
Ken Yasukawa
ABSTRACT Although individually distinct begging calls may permit parents to recognize their offspring, birds nesting in dense breeding colonies where fledglings intermingle might benefit from additional adaptations. For example, if the calls of all nestlings in a brood were similar, parents would need to recognize only one brood call instead of the identity calls of each nestling. We recorded nestling Red-winged Blackbirds (Agelaius phoeniceus) to determine whether their calls function to identify individuals (identity call hypothesis) or broods (brood call hypothesis). We used spectrogram cross-correlation and dynamic time warping as well as call duration, peak frequency, and frequency range to estimate the similarity of begging calls of nestling Red-winged Blackbirds. We recorded individual nestlings on day 5 and on day 9 of the nestling period to determine whether calls of individuals were more similar than calls of different nestlings, and whether calls of broodmates were more similar than calls of nestlings from different broods. We found that calls of 8-d-old individuals were more similar than calls of different nestlings, but the calls of broodmates were not more similar than those of nestlings from different broods. These results were consistent with the identity call hypothesis. We then compared begging calls of pairs of nestlings recorded separately and together on day 9. We found that the calls of 8-d-old nestlings recorded together were more similar than when they were recorded separately. In addition, using playback of begging calls from normal broods and artificial "broods" constructed from the calls of single nestlings, we found that females returned with food sooner in response to the calls of single nestlings (with enhanced call similarity) than to those of normal broods. Our results suggest that similar begging calls may be beneficial for both nestlings and parents, with broodmates fed at higher rates when their calls are more similar and, after fledging, parents needing to recognize only one brood call instead of the identity calls of each fledgling. SINOPSIS Aunque las diferencias individuales en los llamados de reclamo les pueden permitir a los padres reconocer a su progenie, aves que nidifican en grandes colonias de anidación donde los polluelos pueden mezclarse pueden obtener beneficios mediante adaptaciones adicionales. Por ejemplo, si los llamados de todos los polluelos en el nido son similares los padres necesitarian reconocer solo un tipo de reclamo de los polluelos en vez de identificar llamados individuales de los polluelos. Grabamos polluelos de Agelaius phoeniceus para determinar si sus llamados son usados para identificar individuos (Hipotesis de la identidad del polluelo) o para identificar a la progenie (Hipotesis de la identidad de la progenie). Usamos espectrogramas de correlación cruzada y dinamica del tiempo de combeo al igual que la duración del reclamo, el pico de frecuencia y frecuencia del rango para estimar la similaridad de los llamados de los polluelos de Agelaius phoeniceus. Grabamos polluelos individuales de 5 y 9 días de nacidos para determinar si los llamados de los individuos eran más similares a llamados de otros polluelos y si los llamados dentro de una progenie eran ma similares a llamados de otra progenie. Encontramos que los llamados de polluelos de 8 días de nacidos eran más similares que los llamados de diferentes polluelos, pero los polluelos de una misma progenie no fueron más similares que polluelos de diferentes progenies. Esto resultados concuerdan con la hipotesis de la identidad del polluelo. Después comparamos los llamados de parejas de polluelos grabados por separado y los que fueron grabados juntos el día 9. Encontramos que los llamados de polluelos de 8 días de nacidos grabados juntos fueron mas similares que cuando los polluelos fueron grabados por separado. Adicionalmente, usando playback de llamado de polluelos de progenies normales y progenies "artificales" construidos basado en llamado de un solo polluelo, encontramos que las hembras regresaron más rapidamente con alimento en respuesta al llamado de un solo polluelo (con realzamiento en la similaridad del llamado) que para las progenies normales. Nuestros resultados sugieren que la similaridad en los llamados de los reclamos pueden ser beneficiosos tanto para los polluelos como los padres, en donde las tasa de alimentación es mayor cuando sus llamados son mas similares, y después de abandonar el nido cuando los padres necesitan reconocer un solo llamado de la progenie en vez de tener que identificar llamados individuales de cada volanton. [source]