Long-lived birds, particularly territorial raptors, are known to occupy territories for long periods of time. However, little is known of long-term occupancy of nests (see Newton 1979, Burnham et al. 2009). Nest emplacements are valuable resources for raptors because they can provide a signaling function for conspecifics, and ownership of alternative sites may reduce competition with other species and reduce nest ectoparasites (Newton 1979, Hiraldo et al. 1995, Ontiveros et al. 2008, Jiménez-Franco et al. 2014). Their significance can be even greater for hole-nesting birds because cavities meeting species-specific requirements may be in short supply (Newton 1994, Cockle et al. 2011). Thus, high-quality nests of cliff-nesting raptors are sometimes occupied for long periods of time, but documented examples of this are very scarce. Perhaps the most striking case is that of a...