Predation after release is one of the major concerns of hatchery fish conservation and propagation. However, the relationships between the size of hatchery fish, the predator species and their behaviours in natural environments are largely unknown. To understand these relationships, we conducted predation experiments in outdoor tanks and a seminatural stream with exposure to local predators. Masu salmon (Oncorhynchus masou) of two different size classes were used as experimental prey fish in the present study. Camera trap data showed that grey herons (Ardea cinerea) were the primary predator in the experimental system, and that most herons used shallow areas in the morning or evening while feeding. Increasing the density of stocked salmon led to increases in the number of occurrences of grey heron. More importantly, predation by grey herons resulted in a significantly lower survival rate of larger salmon compared with smaller salmon. The results indicate that it is important to understand local predators, adjust the optimum body size of hatchery fish at release and choose the appropriate stocking site and time of day for maximising the effectiveness of fish stocking.

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Birds often hold important positions in the food webs of ecosystems. As a result, interactions between birds and their prey have attracted attention not only in ecology, but also in fields like agriculture and conservation. Avian food resources are well researched in Japan, however there is no database critically reviewing molluscs as a food resource for birds. Here, we present a new database reviewing dietary information for all Japanese bird species. In addition to addressing general diet categories and specific food habits for each bird, we include detailed data on the molluscan prey observed for all species that consume them. The information within this database was collected through intense literary review to provide a complete look at bird species historically present around the country. We also include new information on snail species found in the upper digestive tract of harvested wild birds. This database is publicly available in the Zenodo repository. The information should aid research around the Japanese archipelago, especially projects involving birds or molluscs.

Using whole genome re-sequencing data we study the effects of climate influenced declines in effective population size on the accumulation of deleterious mutations and the response to future climate change in set of populations of two cold-adapted sedentary ptarmigan bird sister species from the Holarctic: rock ptarmigan and willow ptarmigan. We use reconstruct the demographic histories of the studied populations and determine their nucleotide diversity, past and present inbreeding and mutation load. We predict genomic vulnerability (sometimes referred to as offset), defined as the mismatch between current and predicted future genomic variation based on genotype-environment relationships given future climate change scenarios in contemporary populations. We show that relatively small and isolated populations have reduced nucleotide diversity, higher signatures of past and present inbreeding and higher estimates of mutation load. Among the studied populations, the most vulnerable to a mismatch between current and predicted future environmentare rock ptarmigan populations in East Greenland, Iceland and Svalbard in the North Atlantic and among willow ptarmigan, the subspecies residing on the British Isles, red grouse, is the most vulnerable.

Though the Japanese population of Great Cormorants (Phalacrocorax carbo) has increased in recent decades, information on its spread to the northern island of Hokkaido has not been reported outside of Japan. The purpose of this paper is to update the scientific community about the breeding and range ecology of P. carbo, and to provide comparative information on the abundant and similar looking resident Japanese Cormorant (P. capillatus). Several ornithological groups and researchers were contacted in order to gather information about the current distribution and breeding activities of P. carbo in the region. Here the findings of Japanese research groups, translated publications, and direct observations are made available.