Tawny owl vocal activity is constrained by predation risk

• Autor(a) principal: Lourenço, Rui
• Data de Publicação: 2013
• Outros Autores: Goytre, Fernando, Delgado, Maria del Mar, Thornton, Michael, Rabaça, João E., Penteriani, Vincenzo
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10174/9690; https://doi.org/10.1111/j.1600-048X.2013.00157.x
• topic: Tawny owl; vocal behaviour

The vocal behaviour of birds may be influenced by many factors, including the risk of being detected by a predator. In Doñana Protected Area, the tawny owl co-exists alongside its intraguild predator, the eagle owl Bubo bubo . We considered four scenarios to study the vocal behaviour of tawny owls at dusk by analysing: A) the calling rate of all males in 29 sites; B) the calling rate at dusk of males living within the home range of the intraguild predator; C) the calling rate of males living within the home range of the intraguild predator between 60 and 90 min after sunset; and D) the duration of male vocal bouts in visits where eagle owls have called. In scenario A we found that only the number of conspecific males affected the calling rate of tawny owls. In scenario B we observed that the presence of an eagle owl calling constrained the calling rate of the intraguild prey. In scenario C we found that this effect seemed mostly associated to a contemporaneous detection of the intraguild predator’s calls. Finally, in scenario D we found no significant effects on bout duration. These results seem to indicate that tawny owls use their intraguild predator’s calls as a cue to assess predation risk, and then adjust their vocal behaviour in order to minimize predation risk by a predator that may locate its prey by its vocalizations.