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

<p><span>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 </span><span>natural deciduous forest</span><span> located on</span><span> Mt. Gariwang, </span><span>Pyeongchang, and Jeongseon, South Korea from May 2019 to October 2020. We classified ecological factors into topographic, climatic, cover, and demographic factors. T</span><span>hree forest-dwelling small rodent species, striped field mouse (<em>Apodemus agrarius</em>), Korean field mouse (<em>A. peninsulae</em>), and red-backed vole (<em>Myodes regulus</em>), were captured using </span><span>the capture-mark-recapture method</span><span>. The findings showed that the b</span><span>ody mass of three rodent species was not regulated by topographic factors. In addition, a high ambient temperature resulted in a heavy body mass for <em>A. agrarius</em> and <em>A. peninsulae</em>, and the <em>A. agrarius</em> body mass was negatively affected by extreme rainfall. The body mass of each rodent species had a specific response to the cover factors: ground vegetation, understory vegetation, or downed trees. The three species showed sexual dimorphism and two <em>Apodemus</em> species competed with each other. This study reveals that ecological factors affecting body mass differ among species. </span><span>Our findings contribute to enhancing the understanding of variation in the body mass of animals, particularly small rodents, in response to diverse ecological factors.</span></p>