Effects of multiple types’ ecological factors on the body mass of small rodents in a forest ecosystem

The body mass of animals is directly or indirectly affected by multiple ecological factors. However, the effects of ecological factors on body mass are controversial, and a comprehensive study dealing with diverse ecological factors is rare. This study was performed to determine the effects of ecological factors on the body mass of small rodents in a natural deciduous forest located on Mt. Gariwang, Pyeongchang, and Jeongseon, South Korea from May 2019 to October 2020. We classified ecological factors into topographic, climatic, cover, and demographic factors. Three forest-dwelling small rodent species, striped field mouse (Apodemus agrarius), Korean field mouse (A. peninsulae), and red-backed vole (Myodes regulus), were captured using the capture-mark-recapture method. The findings showed that the body mass of three rodent species was not regulated by topographic factors. In addition, a high ambient temperature resulted in a heavy body mass for A. agrarius and A. peninsulae, and the A...., Small rodents were captured using Sherman live traps (7.62 Í 8.89 Í 22.86 cm) placed at each of the trapping points from May to October 2019 and 2020. We used the capture-mark-recapture method to identify captured individuals and estimate population sizes. The traps were baited with peanuts, activated during three consecutive nights in each month, and checked every morning. We marked each captured small rodent with an identification (ID) number together with toe clipping or ear punching. We recorded the capture place, ID number, species, sex, age (adult or juvenile), reproductive condition of each animal, and measured their body mass using a spring balance to the nearest 0.1 g (Pesola AG, Baar, Switzerland). Thereafter, the captured individuals were immediately released at the trapping point at which they were captured. We measured the altitude (meters above sea level) and slope gradient as topographic factors at each trapping point using a portable GPSMAP (Garmin Ltd., Kansas, USA) an..., Excel is required to open the data files.