Essai de validation d’une méthode d’échantillonnage linéaire appliquée à trois espèces de rongeurs d’un peuplement de micromammifères d’un milieu saharien (Guelmime, Maroc)

Abstract

In the view to work out an integrated pest management system against 3 rodent species (Meriones shawi, Gerbillus nanus, Psammomys obesus), pest of the saharian agriculture of Morocco, we had to perfect a sampling method of these mammals both light and relevent to the question. Two separate experimentations were undertaken to test a sampling method founded on trapping out on a strip. The first step consists of the analysis of data provided by Capture-Marking-Recapture operation of all the rodents on a 1 ha (100 .times. 100 m) quadrat, subdivided in 10 .times. 10 m unities. This operation allowed us to determine rationally the geometric characteristics of the strip, that is to say, a 100 .times. 10 m strip made of 10 adjoining squares of 10 m side, each equiped with 4 Manufrance traps. During the second step of this experimentation, two sampling strips were superposed on the quadrat system and all the trapped rodents were removed. This operation allowed us to fix the general timing of operations and, particularly, those of traps checking. Samplings by trapping out must be performed within 4 days with 2 daily trap checkings. These last characteristics were precised by results of a second experimentation which consist of setting up 16 sampling strips. The limits of this linear trapping out sampling method are discussed mainly in the light of behavioural and landscape factors.