SUMMARY.-Rock climbing and Raven Corvus corax ocurrence depress breeding success of cliff-nesting Peregrines Falco peregrinus. Aims: To assess the significance of rock climbing-induced disturbance and Raven Corvus corax occurrence on the breeding output of a cliff-nesting Peregrine Falco peregrinus...
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| Format: | Text |
| Language: | English |
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2004
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| Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.1055.2241 http://www.avibirds.com/pdf/R/Raaf3.pdf |
| Summary: | SUMMARY.-Rock climbing and Raven Corvus corax ocurrence depress breeding success of cliff-nesting Peregrines Falco peregrinus. Aims: To assess the significance of rock climbing-induced disturbance and Raven Corvus corax occurrence on the breeding output of a cliff-nesting Peregrine Falco peregrinus population. Location: Northern Italy-southern Switzerland. Methods: Breeding success, productivity and fledgling rate of 29 Peregrine pairs were analysed in relation to the occurrence of rock climbing activities and Ravens at nesting cliffs. Results: Breeding success and productivity were lower for pairs coexisting alternatively with Ravens or climbers, compared to undisturbed pairs. In addition, pairs settled at cliffs simultaneously occupied by Ravens and frequented by climbers did not fledge any young, suggesting that Raven predation on Peregrine eggs/chicks may be predisposed by human disturbance. Conclusion: It is proposed that rock climbing should be regulated or banned in the proximity of Peregrine nests, in particular at sites hosting Ravens. Key words: Breeding success, cliff nesting, Corvus corax, Falco peregrinus, rock climbing. RESUMEN.-La presencia de escaladores y Cuervos Corvus corax reduce el éxito reproductor del Halcón Peregrino Falco peregrinus. Objetivos: Determinar el efecto de la presencia de escaladores y Cuervos Corvus corax en el resultado final de la reproducción de la población de Halcón Peregrino Falco peregrinus. Localidad: Entre el norte de Italia y el sur de Suiza. Métodos: Se analizó el éxito reproductivo, la productividad y tasa de pollos volados de 29 parejas de Halcón Peregrino en relación a la presencia de escaladores o Cuervos en los cortados con nidos de Halcones. Resultados: El éxito reproductor y la productividad fue menor en parejas que presentaban o bien escaladores o bien Cuervos en los cortados, en comparación con parejas sin su presencia. Además, en las parejas establecidas en cortados ocupados simultaneamente por Cuervos y que frecuentemente son visitadas por escaladores ... |
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