Ranging patterns of two syntopic gerbillid rodents: a radiotelemetry and live-trapping study in semi-desert habitat of Kalmykia, Russia

Abstract

We studied ranging patterns of syntopic folivorous and granivorous gerbils (Meriones tamariscinus Pallas, 1773 andMeriones meridianus Pallas, 1773, respectively) by means of radiotracking and live-trapping in Kalmykia, southern Russia. We hypothesized that ranging patterns exhibited by these rodents would differ in accordance with differences in their preferred diets. Trapping and radiotracking were performed from 23 May to 20 June 2000 on a 12 ha grid divided into 20 × 20 m squares. To assess ranging patterns we estimated the number of grid squares visited by an individual, 100% minimum convex polygon, mean squared distance from the center, maximal distance between individual locations, linearity index, and distance measures at various temporal scales. In accord with expectations, females of folivorousM. tamariscinus exhibited smaller ranges than females of granivorousM. meridianus. Contrary to our expectations both trapping and radiotracking data revealed similar “granivorous” ranging patterns in males of both species of gerbils. MaleM. meridianus andM. tamariscinus were similar in number of burrows used, home range size, and distances traversed. No temporal dependence of distance measures was revealed in either species; males of both species traversed similar distances regardless of time interval for distance measures so that single-night movements and multiday movements did not differ in either species. High food selectivity in maleM. tamariscinus is considered to be responsible for the “granivorous” pattern of space use in this folivorous species.