Abstract

REVOLLO-CADIMA, Susana G.; RICO-CERNOHORSKA, Adriana  and  SALAZAR-BRAVO, Jorge. Reproductive traits variation in wild rodents along an elevational gradient in the Bolivian Andes. Ecología en Bolivia [online]. 2021, vol.56, n.2, pp.68-77. ISSN 1605-2528.

In several rodent species, reproduction is regulated by habitat characteristics. From this perspective, elevation can be an important variable, since at higher elevations resources fluctuate and become more seasonal. Reproductive characteristics are expected to adjust to these conditions (i.e., seasonality), being more seasonal at higher elevation because of the energetic cost it represents. In this contribution we test this hypothesis by analyzing the reproductive patterns of two genera of sigmodontine rodents that are distributed along the eastern coordillera in Bolivia: Akodon and Oligoryzomys. The data were analyzed with a Generalized Linear Model (GLM). For both genera there were more pregnant females in the transition period (Akodon: χ²=6.26, g.l.= 1, p = 0.01; Oligoryzomys: χ²=8.10, g.l.= 1, p = 0.004). Akodon registered larger testicles in transition period at higher elevations (W = 239, p = 0.02), whereas in Oligoryzomys testicles were bigger at lower elevations (W = 256, p = 0.01). Litter size was larger in the dry season at lower elevations only in Oligoryzomys (W = 60.5, p = 0.01). Elevation and time of year affect reproductive patterns and their effect varied among the groups studied. These differences must be related to the plasticity of the species in responding to the variation in food resources availability and species-specific energetic requirements.

Keywords : Reproductive season; Litter size; Sigmodontine rodents; Testicular size.

        · abstract in Spanish     · text in Spanish     · Spanish ( pdf )