From 1991 through 2019 the total population of Short-tailed Albatross Phoebastria albatrus on Torishima increased by 8.5% annually, from c. 500 birds in 1991 to c. 5,000 birds in 2019. In order to decrease extinction risk associated with volcanic eruption, a new breeding site was artificially established at Hatsunezaki using social attraction. One pair bred every year at Hatsunezaki from 1995 through 2003, and four in 2004. Thereafter, the number of pairs increased by 29.1% per year, and 389 pairs laid eggs and 285 chicks fledged in 2018/2019. This high population increase rate was mainly attributable to immigration from the source population at Tsubamezaki on Torishima. Observation of 791 color-banded fledglings from Hatsunezaki showed that they first visited this site at 3.4 years-old, mated for the first time at 4.6 years-old, and bred for first time at 6.2 years-old, with no sex difference. Mean annual death rate was estimated to be 6.6% per year. Using the information of the resident time of individuals, the number of landings taking place every hour and at sunset, the frequency and position of courtship behaviour, and the maximum number of landings, it was possible to predict the number of pairs present several years later.
The Japanese pipistrelle Pipistrellus abramus is one of the most common bats in urban and suburban areas of Japan, from southern Hokkaido to Okinawa. Although the bat is generally nocturnal, it is also active at twilight, i.e., before and after sunset, at which time it may be preyed upon by diurnal predatory birds. During our 710 days of monitoring between April 2012 to May 2022 from the banks of the Koaze River, which flows through Kawagoe City, Saitama Prefecture, Japan, we observed 47 aerial attacks on Japanese pipistrelles by several diurnal predatory bird species. The predatory bird species included the Japanese Sparrowhawk Accipiter gularis, Common Kestrel Falco tinnunculus, Peregrine Falcon Falco peregrinus, Bull-headed Shrike Lanius bucephalus, and Carrion Crow Corvus corone. Our study suggests that bats are a food source for diurnal predatory species of birds in urban and suburban areas.
In Hokkaido, until the 1980’s the Yellow-breasted Bunting Emberiza auleora was a common species in various habitats in the plains, such as moorland, grassland, agricultural land and young woodland. During this period the occurrence rate (No. of transects of occurrence/no. of transects surveyed) was 17.6% in the 1970’s, and 14.4% in the 1980’s. The species rapidly and markedly decreased in numbers in the 1990’s down to an occurrence rate of 4.6%, and thereafter the decrease in numbers continued, with an occurrence rate of 1.2% in the 2000’s. Distribution maps of the species during the breeding season are presented based on data obtained by transect and spot censuses, records from the literature and unpublished personal records.
Molts of remiges of two wild Red-crowned Cranes Grus japonensis were observed in Maizuru retarding basin, Naganuma, Hokkaido. The female (A1) started to first molt in May 2019 when she was 2-years-old, and then molted two years later in June 2021. The male (A2) molted first in May 2018 when he likely was 2-years-old, and then molted three years later in June 2021 when he was raising a chick together with A1. The exact flightless period was uncertain, however, it was 45–56 days in A1, and 51–63 days in A2.
A total of 1,179 nests (55 with no eggs) of Black-tailed Gulls Larus crassirostris were observed at three sites on Bentenjima Island, Okuki, Hachinohe City, on May 15, 2021, and 489 chicks were counted on June 26. Apparent clutch size (excluding nests with no eggs) and fledging success were 1.9 and 21.7%, respectively. Fledging success was lowest on the rock connected to the mainland by a breakwater, presumably because of disturbance by terrestrial animals. A total of 16 individuals with metal leg bands were observed and were 2–22 years old. These were immigrants from Kabushima Island, 10 km northwest of Okuki. Bentenjima Island is an important breeding site of the Black-tailed Gulls in northern Japan, and needs to be monitored.
Japanese names are a useful tool for Japanese speakers to communicate scientifically about birds. However, over 35 years have already passed since the most influential book treating Japanese names for all modern birds (Yamashina 1986) was published. During that time, the classification of birds has undergone major changes. Here we provide a revised list of Japanese names for species of flufftails (Sarothruridae) and rails (Rallidae), which adopts the latest classification system (Gill et al. 2022).