Site fidelity in the Canary Islands stonechat Saxicola dacotiae in relation to spatial and temporal patterns of habitat suitability

We investigate the degree of territory faithfulness of the Canary Islands stonechat Saxicola dacotiae, an endemic bird species of the semi-arid island of Fuerteventura (Canary Islands, Spain), and the spatial and temporal variability of habitat traits related to its breeding success over its whole distribution range. Between 1998 and 2003 we monitored the spatial location of individually marked birds to determine whether they were site faithful. We also analysed the spatial and temporal variability of the abiotic (rainfall) and biotic (food availability, abundance of avian predators and competitors, and nest predation) factors that may influence breeding success in this species. Canary Islands stonechats were strongly site faithful. Out of 106 individuals, 86 (81.0%) were re-sighted during the whole study period, and most re-sightings (76; 88.4%) were in the territory where they were initially caught. Dispersal events were rare both within (1%) and between (≤6%) consecutive years, and detectability of colour-ringed birds was as high as 87%. No significant spatial variation of abiotic and biotic factors affecting success was found at a range of spatial scales. Low spatial variance in the habitat characteristics determining reproductive success could have favoured site fidelity in this species, as costs associated with changing site would not be compensated for by significant increases in survival or breeding prospects in new territories. Strict protection of the areas already occupied by this “Endangered” narrow range endemic bird would be the most effective way of preserving it, due to its strict habitat and microhabitat requirements and its strong site fidelity.