Reproductive activity and population dynamics of Rhipidomys fulviventer (Rodentia: Cricetidae) in the colombian eastern mountain range

Abstract

We studied the reproductive activity and population dynamics of Rhipidomys fulviventer in an Andean oak forest in the Cordillera Oriental of Colombia. A monthly population follow-up was carried out from October 2014 to September 2015 and September 2016 to January 2018, through captures in five fixed stations in an altitudinal interval of 2530 to 2657 m. The reproductive condition in females was established by observation of external morphological characteristics and by the analysis of vaginal smear samples for the determination of the phase of the estrous cycle; in males, reproductive activity was described by testicular histology. Likewise, we estimated the distribution, fluctuation and association of number of individuals captured and age structure with precipitation over time, as well as, longevity, sex ratio and probabilities of survival and recapture using the Comarck-Jolly-Seber model (CJS). In this population of R. fulviventer, females have an unseasonal polyestrous pattern without showing a relation between the frequency of females in each reproductive stage and the variation of the monthly average of rains; adult males were reproductively active, showing sperm every month. It was found that the number of individuals captured is variable without relation to the rainfall regime, a moderate-high constant survival and recapture rate and, differences between males and females in recapture rates, areas of activity, and the average distances traveled, suggesting a promiscuous mating system.