Minimizing interspecific competition by different foraging strategies in two North African desert rodents

Abstract

In most deserts, rodent species are represented numerously, most of them being granivorous. Several studies deal with the question, what the mechanisms of coexistence in such rodent communities are. In this paper the hypothesis is tested, whether the two locomotion typesquadrupedal running and bipedal saltation -may be responsible for the syntopic occurence of the two granivorous desert rodent species Jaculus jaculus (Linnaeus, 1758) and Gerbillus gerbillus Oliver, 1801. The behaviour analysis in a special observation laboratory has shown that the bipedal J. jaculus is less attached to the burrow site, covering a wide area with a wide-meshed net of locomotion pattern, and using only a small part of discovered food resources. The quadrupedal G. gerbillus shows a close contact to the burrow, an intensive utilization of the area round the burrow, and a food utilization of nearly 100%. According to these different strategies in searching for food and food utilization the conclusion can be drawn that (1) by using a wide area J. jaculus always finds new food patches, and (2) that G. gerbillus profits by the fact, that J. jaculus never uses a food patch in total.

Unpredictability of escape trajectory explains predator evasion ability and microhabitat preference of desert rodents

“…On the basis of the relationship we found between trajectory unpredictability and microhabitat preference, the evolution of bipedalism has the potential to influence desert community ecology. It is clear that divergence in microhabitat preference can enable resource partitioning to decrease competition in resource-poor ecosystems 14 , 47 . The substantial differences we have recorded in trajectory unpredictability and open-field anxiety between sympatric jerboas and jirds (Fig.…”

Vulnerability of small and medium-sized prey mammals in relation to their habitat preferences, age classes and locomotion types in the temperate Monte Desert, Argentina

“…A. molinae employed a quadrupedal gait, as other species in the northern hemisphere such as Reithrodontomys megalotis and Gerbillus gerbillus. Others, like G. griseoflavus and E. typus, used jumps in escape situations and a quadrupedal run in short distances or under plant cover (Schröpter and Klenner-Fringer 1991;Taraborelli et al 2003a).…”

Locomotion and Escape Modes in Rodents of the Monte Desert (Argentina)

“…Akodon molinae employed a quadrupedal gait also observed in other murid species such as Reithrodontomys megalotis and Gerbillus gerbillus . Rodent species that use this locomotory pattern must restrict their activities to areas adjoining vegetation where predation risk is lower (Schröpter & Klenner‐Fringer 1991). Graomys griseoflavus and E. typus used jumps in escape situations, and a quadrupedal run in short distances or under plant cover, similar to O. longicaudatus of the Chilean matorral (Vásquez 1994b).…”