Wild boars (Sus scrofa coreanus Heude) are one of widespread large mammals due to their adaptation to the changing environment well while they cause problems invading farm to supply their insufficient foods. Mt. Jeombong area is located in Seoraksan National Park, Gangwondo. I attempted to reveal general diet composition of wild boars as omnivores and whether their diets were affected by seasonal changes, sexes and body sizes.
To understand plant and animal food sources and population structure of wild boar, I collected fecal samples noninvasively from Mt. Jeombong for molecular analysis. Based on previous studies, I considered that wild boar is omnivorous. To uncover the omnivorous diet habits, I categorized food sources as plant and animal sources and analyzed them accordingly. First, I extracted genomic DNAs from their fecal samples. We amplified specific loci targeting plants (rbcL, trnL) and animals (COI). Rosaceae and Bryophyte were the most frequently detected plant food sources at family level although various kinds of plants were detected. Diptera (flies) and Haplotaxida (earthworms) were the most frequent animal food sources detected at order level.
For sex identification, I amplified ZF (Zinc Finger) and SRY (Sex-determining Region of Y) regions targeting wild boars. I could determine their sexes based on these two markers. The sex ratio of collected feces at Mt. Jeombong area was approximately 1:1. According to analysis of feces, the sex ratio of collected wild boars at Mt. Jeombong area was about 1:1. Using the results of sex determination, I tried to compare diet compositions of male and female wild boars. Diet compositions appeared to be similar for both male and female boars except some foods.
Based on the result of average cross-sectional area of the feces, top 25% were classified into large body size group and bottom 25% into small body size group. In the case of large body size group, diets were more diverse, and the Actinidiaceae appeared the highest intake. In the case of small size group, their intake was less diverse than large body size group and the consumption of Fagaceae was the highest.
Traditional methods using morphological traits for identification has many limitations and can be intervened subjective view. Molecular analysis using DNA can provide more various and detailed information. My approach for environment especially collecting fecal samples one of non-invasive method can be also applied to other species or other ecosystems with minimal disturbances. Our results would provide basic data to understand food preferences and habits of wild boar, also understanding population structure can be used facilitate their management. In the future, it will be possible to investigate the habitat density of wild boar at Mt. Jeombong area using individual identification approaches. In addition, non-invasive approach can be applied to other wild animals at Mt. Jeombong for understanding trophic relations and energy flows at Mt. Jeombong.