Paper Title
Sexual size Dimorphism in The Black Bellied Sandgrouse (Pterocles Orientalis, L. 1758)

Abstract
The black bellied sandgrouse (Pterocles orientalis, L. 1758) belongs to the order of Pteroclidiformes. In Algeria, its range extends from the coastal plains to the edges of the desert. In the Ziban south east of Algeria it is largely characteristic of rocky environments and steppes. Studies on the biometry of the black bellied sandgrouse are almost non-existent. For this reason, we opted for phenotypic characterization to demonstrate sexual dimorphism on the biometric scale of the black bellied sandgrouse. In a sample of 63 adult black bellied sandgrouse individuals (n = 30 females and n = 33 males), we performed 693 biometric measurements of the external morphology for all sampled individuals. The biometric characterization performed on the black bellied sandgrouse (n = 63 individuals) reveals an average weight of 421 g ± 33.43, an average skull width of 19.45 mm ± 1.53, the average skull length is 32.64 mm ± 2.24, the average length of the bill is 12.58 mm ± 1.17, the average length of the head is 45.22mm ± 2.72, the average tarsus length is 24.6 mm ± 1.9, the average length of the tibia is 49.54mm ± 3.32, the average length of the wing folded is 21.97cm ± 1.56, the average span is 62.94cm ± 3.31, the average length of the tail is 11.47cm ± 0.65 and the average body length is 45.13 cm ± 2.2. The analysis means difference by using the test (t) of "student" for the biometric characters between the two sexes of the black bellied sandgrouse, showed a significant difference in favor of the males for the characters: weight, length of the beak , tarsus length and total body length (p <0.005). These therefore determine sexual dimorphism at the biometric level. Keywords - Black Bellied Sandgrouse, Size, Biometric Characterization, Sexual Dimorphism