This work was made possible thanks to the grant awarded by the Autonomous Community of Madrid, framed within Order 2825/2017 of 21 September, issued by the Regional Minister for the Environment, Local Administration and Territorial Planning, and later amended by Order 564/2018 of 24 July. These orders establish the regulatory basis for granting public subsidies to non-profit organisations for the implementation of environmental activities and projects in the Community of Madrid. They were published on 9 October 2017 (BOCM No. 240) and 6 August 2018 (BOCM No. 186), respectively. The grant was processed under budget line 48099, “To non-profit institutions,” within the expenditure budget of Programme 456A “ENVIRONMENT.”

We would like to express our gratitude for the support and interest shown in developing all parts of the project to the Director of the Sierra de Guadarrama National Park, Pablo San Juan Benito, and the Scientific Director, Juan Vielva. We also appreciate the collaboration of the National Park’s technical staff: Ignacio Granados, Fernando Horcajada, and Santiago Martín. Likewise, we thank the staff of the Local Population Office, Montserrat Sanz and Aurora de la Rosa, for the assistance and facilities provided for conducting the fieldwork.

The development of all the work was supported by many people from the central office of SEO/BirdLife, especially those involved in project administration and management: Gabriel Martín, David Almonacid, Elisabeth Arroyo, Mar Delgado, Marisa Bayón, and José María Sánchez.