Numbers and distributions of dead animals with mite-induced cutaneous lesions
According to the interviews and data from the fourth giant panda survey of China, the dead animals with mite-induced cutaneous lesions included gorals, serows, takins and wild boars. Among these, gorals and serows were the main animals affected, and there were clear visual records (S3A and B). Dead takins and wild boars with cutaneous lesions were observed rarely, and there were no visual records available. Therefore, we mainly analyzed the numbers of gorals and serows from 2012-2021. The detailed data are shown in table 2, but only the data from the giant panda survey had corresponding Global Positioning System (GPS) information(Zhu et al., 2021). The mean centres of dead gorals and serows in Taibai, Foping, Zhouzhi and Ningshan in 2012 are shown in Figure 1 (Turchetto et al., 2014).
According to the interviews, the animals with cutaneous lesions mainly died on the banks of rivers from November to early April, and the unusual increase in the number of goral deaths began in 2008; therefore, the number of goral and serow carcasses in 2012 reported in the fourth giant panda survey should cover 2008 to 2012. Table 2 and Figure 2A show that increased numbers of deaths due to sarcoptic mange usually persisted for 2-3 years in the goral and serow populations. Among the animals that died from sarcoptic mange in Taibai, Fopin, and Zhouzhi, gorals and serows were the most common from 2012-2014. The number of dead gorals in Huyi was the lowest, which may be related to the distribution of animals. Goral deaths in Ningshan had two peaks in 2012-2014 and 2016-2017 (Fig. 2A). The first goral death event occurred west of the G5 freeway, and the second goral death event occurred in the eastern area of Ningshan, which is near the boundary of Changan District. The peaks in deaths among gorals in Changan District and Zhashui occurred in 2017-2020 and 2019-2020, respectively. Therefore, sarcoptic mange was transmitted among gorals and serows in the Qinling Mountains from west to east. Sarcoptic mange continued to be observed in gorals and serows after the death events.
Additionally, two interviewees from Foping District said that their dogs presented similar moderate cutaneous lesions and that these dogs were free-roaming and often went into the mountains.