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

Abstract

The body mass of animals is directly or indirectly affected by multiple ecological factors. However, the effects of ecological factors on the body mass are controversial, and a comprehensive study dealing 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. agrarius 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 Apodemus species competed each other. This study reveals that ecological factors affecting body mass differ among species. Our findings contribute to enhancing the understanding of variation in the body mass of animals, particularly small rodents, in response to diverse ecological factors.

Adaptive response of Siberian roe deer Capreolus pygargus to climate and altitude in the temperate forests of South Korea

“…In this study, roe deer tended to occupy high‐altitude areas above 800–1000 m a.s.l.. Altitude can affect roe deer's ecology in several ways, including changes in microclimate (Mysterud et al 1997, Pagon et al 2013). Temperature is generally lower at higher altitudes, as previously observed in the study area (Lee et al 2023). Accordingly, temperature's effect depended on altitude.…”

“…The region's annual mean temperature was 7.04°C (-27.40 to 29.19°C), and the annual precipitation was 1668 mm. The altitudinal variation in temperature were observed in the study area (Lee et al 2023), and the annual mean temperature at altitudes of 800, 1000 and 1200 m a.s.l. were recorded as 8.44°C (−23.84 to 29.19°C), 7.13°C (−25.44 to 27.36°C) and 5.57°C (−27.40 to 25.77°C), respectively.…”

“…To determine the study area's temperature, predicted temperature values were modelled at a reference‐point altitude of 1000 m a.s.l., and used as a ‘temperature' variable ( temp ). To construct the temperature model, we used reference‐point temperature data from previous study (Lee et al 2023) and weather data, including data on temperature and relative humidity, from a certain weather station from April to October in 2019–2021. The weather station was located 560 m a.s.l., approximately 8 km away from the study area.…”

“…To construct the temperature model, we used referencepoint temperature data from previous study (Lee et al 2023) and weather data, including data on temperature and relative humidity, from a certain weather station from April to October in 2019-2021. The weather station was located 560 m a.s.l., approximately 8 km away from the study area.…”

Insight into Body Condition Variability in Small Mammals

“…It should be noted that differences in body mass may vary in response to different ecological factors. Similar differences have been confirmed for three Korean rodent species: the red-backed vole ( Myodes regulus ), the Korean field mouse ( Apodemus peninsulae ), and A. agrarius [ 77 ]. These authors do not analyze the body condition index, but their study shows species-specific ecological factors that influence body mass.…”