Crevices selection by Octomys mimax (Octodontidae) in relation to food availability

CAMPOS VALERIA; REUS MARÍA LAURA; CAPPA FLAVIO; ORTUÑO NATALIA; BENINATO VERÓNICA; GIANNONI STELLA

Congreso; SECOND JOINT MEETING OF THE BIOLOGY SOCIETIES FROM ARGENTINA; 2011

Octomys mimax its distribution seems restricted to areas with rocky slopes and ravines, is strictly herbivorous, storage and consume Prosopis torquata, Maytenus viscifolia, Ramorinoa girolae, cactaceaes, Halophytum ameghinoi, Bulnesia retama. We assessed if the food availability can explain the crevices selection by O. mimax. Plant cover were recorded in columnar cactus slopes (CCS), chical (C) and creosote bush scrub (CBS) in the Ischigualasto Provincial Park (San Juan). We selected 15 active crevices (with faeces and caches) and 15 inactive crevices in each communities. The analysis were performed using generalized linear models, and Akaike Information Criterion. The selected models for CCS included P. torquata, Mimosa ephedroides, and Deuterocohnia longipetala. P. torquata was the main resource in actives crevices. The selected models for C included Zuccagnia punctata and R. girolae, both species were higher in inactive crevices. For CBS, the models selected included M. ephedroides, P. torquata and M. ephedroides. M. ephedroides was higher in active crevices. Only in CCS, the crevices are in small ravines with high plant cover so this rodent selected crevices in function to food availability (P. torquata). In C and CBS, without ravines, benefits other than food might be obtained by crevices selection.