Influence of quarries on the cliff-nesting birds and management implications. The majority of cliff-nesting birds are protected and their distribution depends mainly on the availability of cliffs where they can breed. Several of these species can prosper in anthropogenic environments of which quarries are one of the most used. Owing to this adaptation to human-altered landscapes the cliff-nesting birds have access to an additional nesting habitat which acquires special relevance for the development of populations in highly modified environments or in areas where the availability of natural cliffs is limited. Abandoned quarries are especially relevant trough being selected more frequently due to a lesser incidence of human
disturbances. The current management of abandoned quarries in Spain, promoted by legislation, frequently overlooks its ecological potential with the result that measures taken to improve the environment frequently act to the detriment of the cliff-nesting birds which occupied them. In a study carried out in Bizkaia, 73 quarries were inspected locating more than 192 breeding pairs of cliff-nesting birds of 12 species. 72.7 % of the abandoned and 38.9 % of the active quarries were occupied. The study noted the importance of these places on the conservation of the avian community in the province as well as the negative consequences of several of the landscape restoration projects undertaken.

Castillo, I., Elorriaga, J., Zuberogoitia, I., Azkona, A., Hidalgo, S., Astorkia, L., Iraeta, A., Ruiz, F., 2008. Importancia de las canteras sobre las aves rupícolas y problemas derivados de su gestión. Ardeola 55(1), 103-110.