We reviewed the relations between snags and the life of woodpeckers, and snag habitat management.A wide variety of wildlife uses snags for nesting, roosting, feeding and so on.Primary cavity nesting birds such as woodpeckers largely depend on snags and secondary cavity nesters such as titmice use the holes that the former excavate as well as natural cavities.Western countries noticed the importance of snags for wildlife earlier and have considered snag protection in forest management.While in Japan people have paid little attention to the role of snags for wildlife, and snags are not being accepted as part of forests.We discussed the necessity of snag management in Japanese forests.
A single Little Stint Calidris minuta, which has been rarely recorded in Japan, was observed in the flock of Red-necked Stint Calidris ruficollis and Dunlin Calidris alpina from September 9 to 14, 1997, near the Ishikari-gawa in Tobetsu town, central Hokkaido. Identification of the species depended mainly on the split supercilium and the scapular pattern.The bird was in the course of moulting from juvenile plumage to the first winter one.This is the first record from Hokkaido though there have been some records in the Kanto area and southward.
小笠原諸島に棲むウグイスの一亜種ハシナガウグイス Cettia diphone diphone のなわばりを調査した.調査は母島の常緑広葉樹の二次林で,1993年3月21日から4月4日に行った.色足輪で個体識別した雄を1時間追跡し,1分ごとに位置を地図上に記録した.最も外側の地点を結んで得られた多角形をなわばりとし,面積を算出した.調査地には5個体の雄がなわばりをもっていた.なわばりの面積は,1,328から2,604m2,平均2,030.6±s.e.185.6m2であった.この調査では,観察時間が短いために,なわばりを小さく見積ってしまっている可能性がある.しかし,なわばりは重なり合うことがなく,またなわばり間に見られる空いた場所はあまり広ぐなかったので,見積られた面積は実際の大きさと大きく異なってはいないと考えられる.本土の亜種ウグイス C. d. cantans で報告されているなわばり面積は,この調査で得られたものよりも大きかった.また,この調査と同様の方法で算出した本土の9雄のなわばり面積は,平均7,891.1±s.e.1,491.7m2であった.母島では,なわばりが本土のものよりも狭く,生息密度が高いものと考えられた.また母島の調査地では,前年の予備的な調査を含め,例数は少ないものの,雄による雛への給餌や雌への追尾,また巣内の卵や雛が2-3と少ないことが観察された.
Two nests and two chicks of the Styan's Grasshopper Warbler were observed in Birou island, located at the northern coast of Miyazaki Prefecture, on 2 August 1998. This is the first evidence of breeding of this species in Miyazaki Prefecture. The nests were found on short grasses, and the chicks after fledgling were found on the ground near the nests.
One Chiffchaff's skin was collected at Raba Memorial Park(36°44′N, 137°13′E)Toyama Pref., in 22 November 1996. This record is the first record of the Siberian race of the Chiffchaff Phylloscopus collybita tristis from Japan.Two Chiffchaffs were observed at Hegura-jima(37°50′N, 136°55′E)in Isikawa Pref.at the begnning, of November 1997. Another Chiffchaff was also observed at yakumokakusou-chiku (34°44′N, 135° 34′E), in Osaka Pref.from 8-11 November, 1997. These records are the first field observation records of the Siberian race of the Chiffchaff during the autumn migration season from Japan.