2019 年 6 巻 2 号 p. 13-18
Identification of food plants in the diet of Japanese ptarmigan Lagopus mutus japonicus was conducted in the Northern Alps of Toyama Prefecture, Japan during August 2015. Thirty-three fecal samples were collected from a covey comprising a mother and five chicks. Partial sequences of the chloroplast rbcL gene were amplified by PCR using DNA extracted from feces to identify food plants. We identified a total of 22 plant taxa; 13 to species, five to genus, and four to family level. Rarefaction and extrapolated sampling curves revealed that this survey covered approximately 89% of food plant taxa present in the study area. Of the 14 plant families identified from the collected fecal samples, Ericaceae (78.8% of all 33 fecal samples), Apiaceae (24.2%) and Poaceae (24.2%) were dominant. The most dominant family was Ericaceae with seven taxa. The most frequently encountered plant species were Empetrum nigrum (63.6%), Tilingia ajanensis (24.2%) and Vaccinium ovalifolium (21.2%). Thus, the combination of DNA barcoding using fecal DNA and the rarefaction and extrapolation sampling curves are considered to be well suited for estimating the dominant food plants in the diet of the Japanese ptarmigan.