3.2 The tree species preferred by pandas for marking
We counted the species of giant panda marked trees and classified their marking frequency into 3 categories, low frequency (i.e., the species had only 1 to 5 marking records in total), medium frequency (i.e., the species had 6 to 10 marking records in total) and high frequency (i.e., the species had more than 10 marking records in total). There were 16 species of low frequency, 4 species of medium frequency and 3 species of high frequency. The three species with high frequency are Badung oak (Quercus engleriana ), Yaupon pine (Pinus tabulaeformis ), and Huashan pine (Pinus armandii ) (Table S2). These three trees are all locally dominant species with a wide distribution (Ming et al., 1999).