Les conséquences d'un supplément alimentaire sur la dynamique des populations de rongeurs au Sénégal. I - Le cas de Mastomys erythroleucus en zone sahelo-soudanienne

Abstract

The Mastomys erythroleucus population of a sahelo-sudanian woodland bas been studied from August 1976 to October 1979 on two quadrats : a control quadrat (QC) 2.5 ha in size, and a provisioned quadrat (QA) 4 ha in size, where food pellets were regularly provided twice a week since September 1976 (yearly food supplement : 120 kg/ha/yr). The following changes were observed on the provisioned quadrat : (1) an increased population density, (2) an increased production of young, and (3) an improvement of their survival rate. Two further changes were also noticed : (4) while the number of immigrants was not significantly different on the two quadrats during the experiment, the duration of their stay was greater on the provisioned area than on the control area, and (5) the size of the resident females home ranges was decreased. Whereas the experimental increase in food availability and predictibility triggered in this case an increase in Mastomys erythroleucus population density through a better recruitment, it was not influential in preventing the population decline which took place at a similar rate on both quadrats in 197