If you are trying to find out information about a national park, particular species or Spanish government wildlife projects in Spain. The official website “Banco de Datos de la Naturaleza” is the place to start. There is now an enormous amount of information available. papers, maps, census studies and a lot more.
Its a bit heavy to navigate and although there is an English language option, almost everything is in Spanish which is not an issue as online translation is pretty good now?