Status and distribution of diurnal raptors in Central North Algeria, the case of Great Kabylia

Study Extent

The study was conducted in Great Kabylia. The observations were mainly made in the departments of Tizi-Ouzou and Boumerdes, and in part of the north of the department of Bouira. The study region has a Mediterranean climate. It is bound to the north by the Mediterranean Sea, to the east by the department of Béjaïa, to the west by the capital Algiers and the Blida department, and to the south by the M’sila department. Three main ecological zones characterize the study region; the mountain, the valley, and the coast (fig. 1). The mountain range of Djurdjura mainly represents the mountainous relief. It is characterized by a cedar forest with an area of 2,940 ha, in which there are two types of stands: cedar stands (Cedrus atlantica) occupying 80 % of the total area, with a few scattered plants of Holm oak (Quercus rotundifolia), maple (Acer obtusatum and Acer monspessulanum), aleppo pine (Pinus halepensis), zean oak (Quercus canariensis) and yew (Taxus baccata). The remaining 20 % of the area is populated by mixed cedar (cedar and holm oak) (Moussouni, Boubaker, 2015). The shrub layer comprises Quercus rotundifolia, Berberis hispanica, Crataegus laciniata, Rosa sicula, Rosa canina, Lonicera kabylica, Daphne laureola subsp. latifolia, Ruscus aculeatus (Meddour, 2010). The rocky mountain cliffs with cavities and caves favor the settlement of raptors. The scree below forms their hunting grounds. In the middle of the mountain range is the Djurdjura National Park, between the departments of Tizi-Ouzou and that of Bouira, covering an area of 18,550 ha. The valley makes up a larger area than the mountain and coast areas. It is characterized by the presence of a set of human agglomerations (towns and villages), and agricultural land, and on the neighboring hills we find mixed forests of holm oak and cork oak. The coastal strip has a humid climate and is characterized by cork oak forests, areas with shrubland, dune ridges, ponds, and sea cliffs.

Sampling

The census of diurnal raptor nesting pairs and the geolocation of raptor nest sites were carried out for two consecutive years; 2018 and 2019. Counts were carried out during the breeding season from March to July. The total area surveyed on the ground was 552,400 ha. The method adopted for the census of breeding pairs was the systematic search for raptor nest sites in favorable habitats, namely, rocky mountain cliffs (mainly in the Djurdjura national park), seaside cliffs, tall trees, and rocky peaks in the valley. The investigation was sometimes carried out by car (road transect method) at valley level, or on foot (hiking) in places inaccessible to vehicles, especially in the mountains and seaside cliffs. The observations were carried out on a total of 46 roads and routes.

Quality Control

The conservation status of the species was assessed with reference to the IUCN Red List (2020).

Method steps

1. We calculated the total number of the breeding raptor pairs detected in all surveys. Moreover, the species’ totals and the relative abundance (%) (n/N × 100) were also counted: where (n) is the count of pairs of a particular bird species and (N) is the total number of the pairs counted for all species during each count session. For frequency occurrence (%) (Ni/Nt × 100), where (Ni): number of roads and routes where breeding pairs of one species have been observed, (Nt): total number of roads and routes visited. On the maps, in addition to the number of the breeding pairs observed we added the number of juveniles of colonial species to gather more data concerning the size of the colonies. The colonies mentioned in the maps are those of Falco naumanni and Gyps fulvus. Principal component analysis (PCA) was used to show the correlation between diurnal raptor species and the main habitats of Great Kabylia. The distribution of the raptor species according to the three habitat types on the graphic allowed us to separate the raptor species into groups.

1. Aves
   rank: class
2. Accipitridae
   rank: family
3. Falconidae
   rank: family

The study was conducted in Great Kabylia. The observations were mainly made in the departments of Tizi-Ouzou and Boumerdes, and in part of the north of the department of Bouira. The study region has a Mediterranean climate. It is bound to the north by the Mediterranean Sea, to the east by the department of Béjaïa, to the west by the capital Algiers and the Blida department, and to the south by the M’sila department. Three main ecological zones characterize the study region; the mountain, the valley, and the coast