Our research group has been engaged in the study of the ecological interactions between magpies and cuckoos for many years now. In 2007 we were granted a research project by Junta de Andalucía with which we started a longitudinal study on the expression of egg rejection by magpies, with the main objective of studying the variation of this behaviour during the life of individuals.

Mercedes Molina enjoyed a predoctoral grant out of this project and her thesis was the kickoff of the long-term study we have been carrying during the last 15 years. In these years we have used the basic info rmation arising from the continuous monitoring of individually marked magpies to better understand the details of
the interactions between magpies and cuckoos, and also to provide high quality information on other relevant aspects of the biology of reproduction on wild birds.

As part of the group, Marta Precioso Saenz has being helping with the field work for many years and was also able to obtain a predoctoral grant to carry out her thesis on the long-term costs of parasitism to hosts within our study. We have worked during these years with the participation and help of many other researchers.

A great share of the work we have carried out has been in close collaboration with Jesus Avilés, from the Estación Experimental de Zonas Aridas en Almería. During the years we have had also the opportunity to collaborate with other researchers, such as Deseada Pareja (EEZA), Alfredo Sánchez Tojar (University of Bielefeld), Terry Burke (University of Sheffield). We have been financed by Junta de Andalucía and Ministerio the Ciencia y Tecnología through
different projects along the years.