Nesting sites in four buildings listed as of cultural interest (Bien de Interés Cultural BIC) which are managed by the General Directorate of Libraries, Museums and Cultural Heritage. Furthermore, the buildings have in common the fact that they are situated in two of the most important urban SPAs in terms of the number of pairs of lesser kestrel that they host. They are the SPA “Lesser kestrel colonies in the historic city of Cáceres” and the SPA “Lesser kestrel colonies of Almendralejo”.
SPA “Lesser kestrel colonies in the historic city of Cáceres”
The interventions in Cáceres aim to consolidate the colony in the historic centre in three buildings in which the lesser kestrels nest in holes and where there is significant competition with other species (pigeons and jackdaws) and from which nest materials fall to the ground in the city centre. Thus, these cavities need to be improved. Only the parts of the buildings with the greatest presence of breeding pairs have been selected. This is because these buildings are of great heritage value and require actions of a scale that would be beyond the scope of the LIFE project. Scaffolding holes in the eastern façade of the Velatas Museum, on the north façade of the San Jorge Cultural Centre and in the tower of the Provincial Historic Archive will be modified. This will be done by placing a ceramic cover that will allow lesser kestrels to enter but not other species and installing an anti-predator ramp.
In the San Jorge Cultural Centre, the building with the largest number of pairs in this SPA, part of the roof will be improved that is of greatest need for the birds, with cleaning and retiling with curved ceramic tiles to ensure a good seal. Wooden nest boxes will be installed under the roof with corresponding ventilation tiles allowing access by the birds. It will be possible to enter below the roof for monitoring and study of the nest boxes.
SPA “Lesser kestrel colonies of Almendralejo”
In the case of the Church of Our Lady of the Purification part of the roof and tower will be conditioned and remodelled to prevent water filtration in the building and ensure the permanence of the colony. The DGPC has planned to work on the rest of the roof, with a commitment to apply the same criteria of compatibility used in the LIFE project.
99% of the breeding pairs in this building use artificial sites, which makes it an unprecedented and unique colony. Between 1990 and 1994 70 sites were installed in the exterior of the building at the base of the pinnacles and 30 more in the tower in 1995, whilst in 2008 80 wooden nest boxes were installed under the roof with special access holes for each box. Of the 100 nest boxes installed since 1995, 69 were removed in 2006 during maintenance work to prevent water filtration in the building. 60 were substituted by moveable wood-cement boxes which are still in use today. Currently there are 65 external nest boxes in the tower and eaves of the church and 77 next boxes under the roof.
The poor state of conservation of the structure of the roof of the nave and tiles is evidenced by some loss of stability and cohesion in some of its parts. These weaknesses are putting the nesting sites that have been installed in the roof and tower at great risk, and hence the stability of the whole colony. There is a special priority for restoring the two gables of the roof that cover the nave, by substituting the present structure by another of timber that will make it easier to incorporate the internal nest boxes and the access tiles. In addition, a new dimensioning of the guttering for collecting rain water and the installation of pipes to remove it is needed.
The nest boxes under the roof have a low occupancy rate and so unoccupied boxes will be relocated during the work (18 of the 22 existing boxes) and placing them halfway up the roof, where several individuals have been seen during the period of nest-site selection to attempt access. The nest boxes will be accessible through a special tile which has been designed to avoid a negative visual impact.
At the top of the tower mobile boxes will be substituted by fixed ones given that significant water filtration has been detected here. They will be made from building materials, isolated and with anti-predation devices, ventilation and monitoring access. They will be distributed in the niches and crevices that form part of the steps that are situated on the four corners of the upper terrace of the tower. The same will be done to the mobile nest boxes on the turrets on main tower. The windows of these turrets will be covered by metallic fabric in metal frames to prevent access by pigeons. A small hole will be made in this material, corresponding to the entrance hole of the nest box to allow access by the lesser kestrels. All the nest boxes will be externally finished such that they avoid visual impact and will be perfectly integrated within the building.
To prevent chicks from falling out of nests, a perimeter parapet will be installed that will be well disguised in the areas where there are nest boxes in the eaves and the tower. In the terrace of the tower a parapet will also be placed in the area below the four guard rails.
Intervention criteria and analyses previously carried out by the General Directorate of the Environment will be taken into account. Traditional materials will be used, compatible with the historic fabric of the buildings to respect the protection of heritage, following conservation criteria for historic buildings. The work will be carried out outside the breeding season of the lesser kestrels.
Before starting the work, the mandatory reports and licences will be obtained. To save time, this documentation will be applied for at the time that the projects are written-up to take advantage of those months when it is not possible to undertake the building work.
The involvement in this action of technicians specialised in building restoration and special techniques for conservation of lesser kestrel habitat will ensure the correct execution of these works. They will be undertaken by a multi-disciplinary team, based on the development of protocols for the implementation of maintenance work on buildings of heritage value and breeding pairs of lesser kestrel.
Responsible for implementation: General Directorate of the Environment, General Directorate of Libraries, Museums and Cultural Heritage and DEMA.