The present study aimed to examine the relationship among urban waterfowl numbers, diversity indices, and river-crossing structures in the Nogawa, Sengawa, Zenpukuji, and Kandagawa Rivers, which are typical urban rivers flowing through Musashino Plateau in Tokyo. In this study, we conducted surveys of over 20 species of bird by using the line census method from May 2016 to January 2017. We also measured parameters such as river width, waterway width, land width, and height from the waterway to the bank crest and analyzed these with respect to the bird survey results. The analysis by generalized linear model revealed that members of the family Ardeidae and Anas crecca tended to use narrow habitats, whereas Anas acuta and Anas platyrhynchos tended to use spacious habitats. From this, it was thought that the narrow structure of the urban river was effective in covering pressure of human for some birds. Additionally, the analysis by multiple regression revealed that larger river-crossing structures were positively associated with diversity indices. The results suggest that the river-crossing structures affect both waterfowl amount and diversity.
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.
Sika deer (Cervus nippon) have expanded their distribution and population size have increased, which has resulted in a negative impact on natural forests and plantations. Thus, wildlife managers are required to cull the deer in these environments. However, there are no tools to evaluate the appearance patterns of sika deer on plantations. Using time-lapse photography from August 16 to November 19, 2017, we investigated the number of deer appeared and the time they appeared, their group size during the daytime to assist in establishing a proper culling program for the deer on plantations. The number of deer appeared and the time they appeared varied across plantations and months; hence, wildlife managers were required to select proper culling sites and seasons from the data found. We found that 1-2 deer groups accounted for 90% or more of the total herd, and that the sika deer appeared on plantations during the daytime. Thus, wildlife managers were able to implement the appropriate culling method. Therefore, time-lapse photography clarified the deer appearance pattern during the daytime. Additionally, this photography can work in the long term, and so would have lower survey efforts than direct observation.