To study the moult of remiges and rectrices of the White-cheeked Starling Spodiopsar cineraceus, we collected 10,292 of these feathers at their communal roost in Kindai University Higashiosaka Campus, Higashiosaka City, Osaka Prefecture, central Japan, between 2008 and 2009. Feathers were identified as primaries (P1 to P10), secondaries (S1 to S6), tertials (Te1 to Te3) and rectrices (R1 to R6), and as adult feathers or juvenile ones. The birds had begun moulting before we started sampling in 2008, while we ceased sampling before they completed moulting in 2009, as they were driven away from the roost. We collected their feathers between early June and the end of September, while they used the roost from late May through November. They started moulting from the innermost primary (P1) to outer ones, from the outermost secondary (S1) to the inner ones, and from the center tertials (Te2) to the inner (Te3) and then the outer ones (Te1). As rectrices were replaced from the central (R1) but within a short period of time, the sequence of moult of rectrices was unclear. The moult sequences were the same for adult feathers and juvenile ones. Juvenile primary feathers were collected later in the season than adult ones. The inner primaries of adults, and the inner secondaries of both adult and juveniles, were relatively scarce. These observations indicate that adults shed their inner primaries before they formed the summer roost, and they suspended the moulting of the inner secondaries in September, presumably because of pair formation in autumn. The collection of shed feathers under the roosting area could be simple and useful technique to study moult.
The status of seabirds breeding on Daikoku Island, eastern Hokkaido, Japan, was updated. The number of nest burrows of Leach's Storm Petrel Oceanodroma leucorhoa was estimated using nest densities and areas of each habitat in 2014, and was 415,674; about half of the annual population estimates for 1972–1994. The number of nest burrows of the Rhinoceros Auklet Cerorhinca monocerata was estimated similarly, and was 77,734; about 10 times the estimate for 1986. These population changes were due to changes of both nest density and area of habitats. The number of nests of the Slaty-backed Gull Larus schistisagus was directly counted, and was 5–30 in 2014–2018; less than 5% of that recorded annually from 1982–1994 (3,500–8,200 pairs). The number of nests of the Japanese Cormorant Phalacrocorax capillatus was counted directly and was 120–245 in 2014–2018, except 2016; similar to that seen in 1980–2015 (172–321 nests). Disturbance by White-tailed Eagles Haliaeetus albicilla was observed in the colonies of Slaty-backed Gulls and Japanese Cormorants.
The Common Starling Sturnus vulgaris is a winter visitor to Japan, with more records in the western region. In Hokkaido, this species is known as an accidental visitor, and some reports suggest that the number of observations recorded in the Sapporo region have recently increased. In this study, we first reported our observations of the starling in Oshima Peninsula, southern Hokkaido, where this species had not been previously recorded. We then collected published observation records from 1987, when the first starling was recorded in Hokkaido, until 2018. From these records we examined the distribution of observations of the starling and assessed whether the number of them flying to Hokkaido has increased during this period. The birds were widely observed in Hokkaido, with the number of records occurring more frequently in the Sapporo, Ishikari and Okhotsk regions. The number of observation records was high both in spring (April) and fall (October), suggesting that the birds might visit Hokkaido during their migration. The annual number of observation records showed an increasing trend, which occurred every year from 2004. In addition, the number of birds per observation seemed to increase in recent years, but with high interannual variability. Therefore, careful attention should be paid to the changes in the number of starlings and their distribution throughout Japan, including Hokkaido.
The Japanese Green Pigeon Treron sieboldii has been reported to drink water from the sea or mineral springs in Hokkaido, Gumma and Kanagawa. Especially, at the Terugasaki seashore, Kanagawa Prefecture, the seasonal change in the number of birds visiting the shore to drink seawater is well known. This study describes the seasonal change in the number and behavior of birds visiting and drinking water at Myogadani springs, Hiroshima, in 2017 and 2018. During the study period, a video camera study documented 7,234 birds (3,381 males, 3,468 females and 385 juveniles, without individual identification) as visiting the mineral springs and drinking the water. Ninety-eight of the recorded birds were seen to have white stringy materials dangling from the cloaca. Examination of these materials indicated them to be tapeworms of the subfamily Eucestoda. This suggests that in addition to its main food, i.e. fruits, the Japanese Green Pigeon also eats arthropods.