Régime trophique des rapaces nocturnes dans deux stations du centre algérien (Sebseb et Zelfana)

Abstract

The present work took place in the two stations in Ghardaïa region (station of Sebseb and Zelfana). During the 6 months of study from September 2017 until February 2018. The diet showed a number of prey by regurgitation in the Ascalaphe Owl varying between 1 and 3 prey. While in the regurgitation of Bowl owl, it's varying between 1 and 4 prey. The average number of prey per pelota is variable in both raptors. It depends on the size of prey ingested. The study of the diet of Bubo ascalaphus based on the analysis of 180 balls of rejection allowed to highlight six categories preys, in particular, Arachnida, Insecta, Reptilia, Rodentia, Chiroptera and Aves. With rodent dominance (AR = 51.62%). The most represented prey species are Gerbillusgebillus (AR = 20.43%) and Gerbillusnanus (AR = 16.13%). While the T. alba prey are divided between six prey categories (Arachnida, Insecta, Reptilia, Rodentia, Chiroptera and Aves), and the most are belong to the category of Aves (AR = 50%). Streptopelia sp. (AR = 31.54%), Passireform sp. (AR = 7.38%) and Passer sp. (AR = 6.71%) are the prey most consumed by this raptor. The most advantageous biomass category is Rodentia in both raptors. Moreover, in terms of prey species, Gerbillusgebillus (B = 20.86%) for Buboascalaphus is the most profitable in biomass. While for TytoalbaStreptopelia sp. (B = 67.97%) is the most profitable biomass. The values of the Shannon-Weaver diversity recorded for B. ascalaphus (H '= 1.10 bits) and T. alba (H' = 0.68 bits) reflect low diversity of environments exploited by the two predators. Following the values of Equitability which are in order 0.41 for B. ascalaphus and 0.42 for Tytoalba these values indicate that a diet is a little varied. In this fact, we can say that the two predators are opportunistic in their predation in the two stations in Ghardaïa region (station of Sebseb and Zelfana).