Effects of local climate on nest cavity characteristics 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 Aurès Mountains. This species, similar to all woodpeckers, is important for the integrity of ecosystems, especially as it provides nesting cavities and contributes to the availability of habitats for several secondary cavity nesters that cannot excavate their hollows. This work aim to characterise the Levaillant’s Woodpecker’s nest cavities and to test the effect of local climatic conditions on the size and orientation of these cavities. Surveys were carried out in the breeding seasons of 2018 and 2019 using the point count method to search for the nests. Based on nest measurements conducted on a total of 52 available nest cavities, our results reveal that entrances are dominated by round shapes (94.2%) as compared to oval shapes. The mean height and width values of the cavity entrances were found to be 7.26 ± 1.51 centimetres and 7.11 ± 1.44 centimetres. The depth of the internal chamber and its width were estimated to be 35.42 ± 7.82 centimetres and 17.95 ± 4.01 centimetres, 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 behaviour 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 or low altitudes.