2.2 Sampling of small mammals
Small mammals, including glires (Rodentia and Lagomorpha) and insectivores (Eulipotyphla), were sampled seven times in the three forest types from 2017 to 2020 (four surveys in the Meigu Dafengding Nature Reserve and three surveys in the Heizhugou Nature Reserve). During each survey, three sample sites were placed at 2200 m, 2600 m, and 3000 m a.s.l. for each forest type (a total of 54 sample sites), and each sample sites were at least 500 m away from each other. In June 2017, September 2017, March 2018 and June 2018, 27 sample sites were set in Meigu Dafengding Nature Reserve. In April 2020, July 2020, and October 2020, 27 sample sites were set in Heizhugou Nature Reserve.
At each sample site, 49 trap stations were evenly spaced in seven rows and spaced 5 m apart, with each station consisting of a snap trap (155 × 85 mm). Two additional trap stations consisting of two plastic buckets (450 × 300 mm) and one plastic sheet (8 × 1 m) were set up at each site. The plastic sheet was fixed vertically to the ground and perpendicular to other sheets, and the two plastic buckets were buried at each end of the plastic sheet (Liang, Dai, & Li, 2008). We used fresh peanuts as the bait for snap traps which were during the following morning (8:00 am-11:00 am). Each bucket was filled with 300–500 ml of water to prevent small mammals from escaping. All traps were set for three consecutive days at each site. Our manipulation was in accordance with the National Wildlife Conservation Law of China.
All captured individuals were measured, and we recorded information of body length (mm), body mass (g), ear length (mm), tail length (mm), sex, and hind foot length (mm). All tissues and specimens were deposited at the Nature Museum of Sichuan University. The taxonomic system used in this study followed that for China’s mammals diversity and geographic distribution (Jiang et al., 2015).