WITHDRAWN: Local climate influence on size and orientation of nest cavities of a North African endemic woodpecker

Abstract

Levaillant’s Woodpecker Picus vaillantii is a primary cavity nester endemic to the forests of northern Africa, including the cedar forest in Aures Mountains. This species, as like all woodpeckers, is important for the integrity of ecosystems, especially since it provides nesting cavities and contributes to the availability of habitats for several secondary cavity nesters that cannot dig their own nests. To characterize for the first time the Levaillant’s Woodpecker’s nest cavities and to test the effect of local climatic conditions on the sizes and orientations of these cavities in Aures cedar forests of north-eastern Algeria surveys were carried out in 2018 and 2019 breeding seasons using the point count method to search for the nests of the Levaillant’s Woodpecker. Based on measures realized on a total of 52 available nest cavities, results reveal entrances with a dominance of round shapes (94.2%) compared to oval shapes. The mean height and width values ​​of the cavity entrances were 7.26 ± 1.51 cm and 7.11 ± 1.44 cm. The depth of the internal chamber and its width were estimated at 35.42 ± 7.82 cm and 17.95 ± 4.01 cm respectively. Unlike the average values ​​of the volumes of the internal chamber, those relating to the entrance area and orientation vary significantly according to altitude and climatic conditions. Indeed, when climbing towards the summits, the cavities widen and turn to the west-southwest. This behavior of the Levaillant’s woodpecker seems to help it to benefit from maximum sunshine at high altitudes and to avoid predators and competitors more abundant at medium low altitudes.