著者
三島 冬嗣
出版者
The Ornithological Society of Japan
雑誌
(ISSN:00409480)
巻号頁・発行日
vol.17, no.79-80, pp.218-219, 1962-12-31 (Released:2009-02-26)

伊豆諸島と四国,本州瀬戸内海周辺と琉球諸島に棲息する一連のキジバトは羽毛の色彩に於て普通のS. o. orientalisよりも更に赤味強く濃いと云う共通の特徴による区別があり,筆者はこれらの範囲に分布するこの種S. o. stimpsoniに同定した。分布は確実には次の通りである。伊豆諸島〔三宅島,御蔵島(観察),八丈島,八丈小島,鳥島(漂鳥)〕,四国,本州瀬戸内海周辺〔広島〕,九州,屋久島,奄美大島〔大島,喜界島,徳之島〕,琉球諸島〔伊是名島~与那国島〕。
著者
上田 恵介 小林 和夫
出版者
The Ornithological Society of Japan
雑誌
日本鳥学会誌 (ISSN:0913400X)
巻号頁・発行日
vol.39, no.3, pp.103-105, 1991-05-25 (Released:2007-09-28)
参考文献数
3
被引用文献数
2

We observed that Japanese White-eyes Zosterops japonica sucked honey dews secreted by two species of small jumping plant-lices, Heterophylla cubana and Stenopsylla nigricornis. This is the first observation of inter-specific relationship between homopteran insects and white-eyes. Such a foraging manner might be common in White-eyes. Although honey dew of homopteran insects is not neccessary to White-eyes as nectar resource, the homopteran insects seems important as insect foods.
著者
Keiichi AOTSUKA Hideki ENDO
出版者
The Ornithological Society of Japan
雑誌
ORNITHOLOGICAL SCIENCE (ISSN:13470558)
巻号頁・発行日
vol.21, no.1, pp.79-92, 2022 (Released:2022-01-31)
参考文献数
97

Alcidae (auks) is a family of wing-propelled diving Charadriiformes, which includes 24 extant species distributed in the Holarctic region. Here, we describe a fossil humerus of Pliocene Alcidae (approximately 4.5–3.5 Ma) from the Fukagawa Group in Hokkaido, Japan. Although this specimen is incomplete and the diagnostic characters of the specific genus are lacking, it shares similar characteristics with Uria, such as the size, dorsoventrally compressed humeral shaft, low and smooth crista deltopectoralis, and a nearly rectangular supracoracoideus scar. While several Alcidae fossils have been reported from the Miocene–Pleistocene deposits (23.0–0.0117 Ma) of the Eastern Pacific (i.e., Mexico and California, USA), little is known about fossils from the Western Pacific (i.e., Asia), most of which have been found from Pleistocene deposits (approximately 0.7–0.12 Ma). This study, reporting the first Pliocene Alcidae from the Western Pacific, implies that the Alcidae were already distributed in the Holarctic region during the early Pliocene.
著者
Makoto HASEBE Masayuki SENZAKI
出版者
The Ornithological Society of Japan
雑誌
ORNITHOLOGICAL SCIENCE (ISSN:13470558)
巻号頁・発行日
vol.21, no.1, pp.115-119, 2022 (Released:2022-01-31)
参考文献数
8

Pallas's Reed Bunting Emberiza pallasi was confirmed to be breeding in grassland at the Volchinka River mouth, Northern Sakhalin, Russia, in July 2019. The density of the species was 0.17 territories/ha. The observed individuals were identified as either E. p. polaris or E. p. pallasi based on their morphological characteristics and geographical location. Two nests and two fledglings were discovered. This is the first evidence of this species breeding on Sakhalin Island. Since northern Sakhalin is several hundred to a thousand kilometres away from the previous known breeding range, our study suggests a possible range expansion of this species.
著者
江口 和洋
出版者
The Ornithological Society of Japan
雑誌
日本鳥学会誌 (ISSN:0913400X)
巻号頁・発行日
vol.38, no.3, pp.141-148, 1990-03-25 (Released:2007-09-28)
参考文献数
11

1982年2月より1985年5月まで熊本県上益城郡矢部町の緑川水系五老ヶ滝川と笹原川流域においてカワガラスの営巣習性についての研究を行った.1)造巣行動は8月から4月までみられ,とくに12月と1月に頻度が高かった.8-10月の造巣行動は初期段階で終息し,12月以降の造巣のみが産卵以上のステージにまで進んだ.2)造巣への雌雄の貢献度はほぼ等しく,両性間での分業は見られなかった.3)発見された53巣のうち,橋(26巣,49%),崖や石垣(13巣,25%)への営巣が多く,ほかに暗渠の中,排水口,岩,滝の裏などに造られていた.人造物への営巣が多かった(64%).橋への営巣は4年間で増加し,崖•石垣の利用は減った.4)2回目繁殖では巣の再利用が多かったが,経年使用は稀であった.営巣場所は毎年繰り返し利用される傾向が強かった.5)営巣場所による繁殖成功率の有意な差はみられなかった.6)繁殖つがい数は1982年の6つがいから1985年には13つがいまで漸増した.7)4年間で潜在的な営巣可能場所は変化しなかったが,河川拡張工事により採餌に好適な平瀬が増えたことが,繁殖個体数の増加をもたらしたものと思われる.
著者
Athira S. VARIAR N. R. ANOOP P. A. VINAYAN P. A. AJAYAN N. S. SUJIN Askar ALI P. K. PRASADAN M. K. SMIJA Santhanakrishnan BABU
出版者
The Ornithological Society of Japan
雑誌
ORNITHOLOGICAL SCIENCE (ISSN:13470558)
巻号頁・発行日
vol.20, no.2, pp.185-199, 2021 (Released:2021-07-31)
参考文献数
51
被引用文献数
2

Understanding the patterns and drivers of bird species composition and diversity outside Protected Area networks is essential to develop landscape-level conservation strategies. The Western Ghats' coffee plantations of India form an important agro-ecosystem and help maintain a significant portion of regional avian diversity. However, knowledge of the composition and functional diversity of birds in differently managed coffee plantation is lacking from the Western Ghats. In this study, we compared the composition and functional diversity of resident birds between shade and open coffees plantations. We counted 3,846 birds of 87 species, and found species richness to be higher in shade (78 species) than in open coffee plantations (55 species). Interestingly, 32 species were unique to shade and nine were unique to open coffee plantations, with 46 species found in both types of plantation. Overall species composition and functional diversity were different in differently managed plantations. Species richness and abundance (birds/point/visit) were higher in shade coffee, reflecting the availability of multiple strata and habitat heterogeneity. Results revealed that different farm management practices can affect functional bird richness and its abundance in coffee plantations. Therefore, retaining shade-trees of native varieties in coffee plantations is important for supporting high functional diversity, richness, and abundance of birds in the coffee plantation of the Western Ghats.
著者
Green CHOI Hyung-Kyu NAM Seok-Jun SON Min Seock DO Jeong-Chil YOO
出版者
The Ornithological Society of Japan
雑誌
ORNITHOLOGICAL SCIENCE (ISSN:13470558)
巻号頁・発行日
vol.20, no.1, pp.27-37, 2021 (Released:2021-02-09)
参考文献数
56
被引用文献数
3

Rice fields provide important inland stopover sites for migratory shorebirds. However, stopover duration and habitat use depend on the environmental conditions in the rice fields, which constantly change due to agricultural activities. This study determined the characteristics of habitat use in two shorebird species, the Wood Sandpiper Tringa glareola and Common Greenshank T. nebularia, in rice fields with different habitat conditions resulting from physical changes (field type: fields flooded after plowing, with high water levels after harrowing, or with low water levels after harrowing) and chemical changes (pesticide use: environmentally friendly or conventional farming) from agricultural activities around the time the migratory shorebirds arrive. The study was conducted during the spring stopover periods of these shorebird species in 2015 (May 2–20, 19 days) and 2016 (May 2–21, 20 days), during which we observed the characteristics of their habitat use and estimated the densities of potential prey. Both Wood Sandpiper and Common Greenshank were observed to use flooded fields with low water levels after harrowing. As for pesticide use, potential prey animals were most densely populated in environmentally friendly fields, for which only the large-bodied Common Greenshanks showed selection. This species-specific habitat use seems to be closely associated with body size-dependent prey availability and prey species selection. The small-bodied Wood Sandpiper was more affected by physical than chemical factors. These findings suggest that rice fields—major inland stopover sites for shorebirds—provide different habitats depending on agricultural activities. The study results also have practical implications for future improvement of inland shorebird habitat through efficient rice field management sensitive to the needs of migratory shorebirds.
著者
山本 弘
出版者
The Ornithological Society of Japan
雑誌
(ISSN:00409480)
巻号頁・発行日
vol.20, no.90, pp.239-242, 1971-12-25 (Released:2008-12-24)

(1) On the occasion of the Tokachi-oki Earthquake (May 17, 1968), a male North Green Pheasant was obsrved in cries reacted to the earthquake in the field.That was at the natural grove in Miyako region, Iwate Prefecture, the seismic intensity was corresponded to IV there, noise by the quake was slight, the pheasant's cries might be heard with every interval about 5 seconds during the definite period of time in distinct quake.Which cring was obviously frequent compared with that of the ordinal habit of him.The every crying was corresponded to the displaying crow, not of the screaming in terror.(2) On the occasion of the Kanto Severe Earthquake (Sept. 1, 1923), Dr. Seiichi KUZU could hear no cries among the many Green Pheasants he had being breeded in Tokyo.(3) On the occasion of a weak earthquake at Sendai City (June 20, 1969), the seismic intensity presumed was about II-III, many glazed windows of a structure gave out violent noise, a male North Green Pheasant, which had been occasionary crowed with very long intervals at the neighbouring bush, began to crow continuously with short intervals were shortened still more in proportionally to the intensification of the windows' noise up to nothing and the crows duplicated each other, and then the crows retrogressed gradually with the noise finally to silence.(4) According to the mentioned facts, the author concluded that the Green Pheasant may reacts against the noise only on the occasion of the earthquake in the male's displaying crow during the breeding season, notwithstanding there had been a firm popular view among the Japanese people that the Green Pheasant screams in terror under the quake of the earth.
著者
釜沢 忠夫
出版者
The Ornithological Society of Japan
雑誌
(ISSN:00409480)
巻号頁・発行日
vol.14, no.68, pp.52-53, 1957-02-28 (Released:2009-02-26)

The author made a close observation on the mechanism of the bill and the tongue in captive Crossbills, Loxia curvirostra japonica Ridgway. The bill helps the feet in their climing and acrobatic behavior on the branch. To eat pine-cone seeds, the bill half-opened to be not crossed, and they insert it between the scales, closing it to be crossed to push asaid them. The movement of the tongue was also examined closely. It is put out very fast (about 5 times a second) and is pulled back with a pine-cone seed between the 'tip-tongue' and the 'root', i. e. at the notched end of the former; and the 'wing' of the seed is held sideway to be cut off by the bill. The author also reports of their 'hanging-sleep' under pine-tree branch in wild and captive birds.
著者
川口 敏 山本 貴仁
出版者
The Ornithological Society of Japan
雑誌
日本鳥学会誌 (ISSN:0913400X)
巻号頁・発行日
vol.52, no.1, pp.29-31, 2003 (Released:2007-09-28)
参考文献数
7
被引用文献数
8 6 2

Sixty seven pellets of Long-eared Owls, Asio otus, were collected in a village, Ehime Prefecture, during 19February 2001to 6 April 2001. The bones of 164 Mus musculus, ten Micromys minutus, two Apodemus speciosus, two Rattus sp., seventeen Pipistrellus abramus, two Myotis macrodactylus, twelve Crocidura dsinezumi and a bird were found in the pellets. M. minutus, P. abramus, M. macrodactylus and C. dsinezumi were new records in diet of the Long-eared owls.
著者
Peng XU Hao CHEN Duoying CUI Chunrong LI Guoyuan CHEN Yongqiang ZHAO Changhu LU
出版者
The Ornithological Society of Japan
雑誌
ORNITHOLOGICAL SCIENCE (ISSN:13470558)
巻号頁・発行日
vol.19, no.1, pp.93-97, 2020 (Released:2020-01-30)
参考文献数
25
被引用文献数
3

The Red-crowned Crane Grus japonensis is an endangered species in East Asia. The western flyway population in China has been in steady decline in recent years because of the loss and deterioration of the natural wetland habitat it requires. To enhance this migratory Red-crowned Crane population, a project was designed to return captive Red-crowned Cranes to the wild in 2013 and 2015 in the Yancheng National Nature Reserve (YNNR). This reserve is the most important wintering site for the continental migratory population. The survival rate of introduced Red-crowned Cranes was 40%. However, aggregation of introduced and wild individuals was not observed. Introduced individuals did not pair with wild individuals nor did they migrate to breeding areas with them. They remained in the core zone of the YNNR over summer. Here, we report the first breeding of introduced Red-crowned Cranes in the YNNR in 2017 and 2018. Suitable rearing methods and the use of aircraft to inform them of the migration route are necessary. Further research is necessary to confirm the migratory status of the cranes that are reared in the reserve.
著者
Christin L. PRUETT Daniel D. GIBSON Kevin WINKER
出版者
The Ornithological Society of Japan
雑誌
ORNITHOLOGICAL SCIENCE (ISSN:13470558)
巻号頁・発行日
vol.3, no.2, pp.133-138, 2004 (Released:2005-07-13)
参考文献数
24
被引用文献数
8

The conservation status and evolutionary distinctiveness of the isolated, small, and endemic population of Amak Island Song Sparrows (Melospiza melodia amaka) have been equivocal. Coupled with a reassessment of phenotypic evidence for this taxon, we used mitochondrial cytochrome b sequences and eight microsatellite loci to evaluate the relationship of the Amak population to nearby Song Sparrow populations. Phenotypically, M. m. amaka is not a valid taxon, and we found that Amak Song Sparrows possess no unique haplotypes and have allele frequencies and heterozygosity values similar to those in other populations. Congruence between genetic and morphological evidence suggesting no diagnosable differences leads us to propose that this population is not an evolutionarily significant unit (ESU), not a valid subspecies, not a distinct population segment (DPS), nor a diagnosable conservation unit, but rather a sink colonized by regional source populations.

3 0 0 0 OA 北海道紀行

著者
山階 芳麿
出版者
The Ornithological Society of Japan
雑誌
(ISSN:00409480)
巻号頁・発行日
vol.6, no.29, pp.219-242, 1930-04-30 (Released:2008-12-24)
被引用文献数
2 1
著者
内田 博
出版者
The Ornithological Society of Japan
雑誌
日本鳥学会誌 (ISSN:0913400X)
巻号頁・発行日
vol.35, no.1, pp.25-32, 1986-10-25 (Released:2007-09-28)
参考文献数
6
被引用文献数
9 7

(1)1968-84年に,埼玉県中央部の比企•武蔵丘陵を中心とする森林で4種のタカ類(サシバ,ハチクマ,オオタカ,ツミ)の観察を行ない,そのうちサシバ,ハチクマ,ツミの3種の巣の周辺でスズメとオナガが繁殖しているのを確認した.しかし,オオタカには,そのようなことは見られなかった.(2)サシバの巣の周辺では,丘陵内ではふつう見ることのないスズメが数番いひんぱんに観察され,サシバの巣から数mの範囲内に巣をつくり繁殖してい虎.調査した11巣中,スズメが見られたのは9例で,合計9巣が確認された.スズメの見られた時期はサシバの繁殖時期と一致し,5月中旬から7月初旬にわたった.(3)ハチクマの巣の周辺でもスズメが見られ,繁殖した.調査した6巣中,スズメが見られたのは4例で,2巣が確認された.(4)ツミの巣の周辺では,一群のオナガが観察され,周辺数10mの範囲内に複数の巣がつくられた.調査した10巣中,8例でオナガが長期間観察され,オナガが巣の周辺に見られないとされた残りの2例でもオナガがツミの巣の林に短時間現われた.オナガの見られた8例の場所では,合計7巣のオナガの巣が確認された.(5)オオタカの場合は,調査した19巣の付近で繁殖する鳥は見られなかった.
著者
川路 則友
出版者
The Ornithological Society of Japan
雑誌
日本鳥学会誌 (ISSN:0913400X)
巻号頁・発行日
vol.36, no.4, pp.153-158, 1988-08-25 (Released:2007-09-28)
参考文献数
9
被引用文献数
1 1

1) 南九州低山帯の常緑広葉樹林と植栽林め混在する環境における繁殖鳥類群集の特徴を調べるために,1985年から1987年のそれぞれ5月から7月にかけて,鹿児島市近郊の鳥帽子岳(標高522m)でライントランセクト法によってセンサスを行った.2)調査区はアカガシ,タブの優占する広葉樹林,ヒノキやスギの植栽林,およびそれらの混交林がモザイク状に存在するA区と,農耕地に植栽林の混じるB区であった.3)調査期間中,A区で28種, B区で24種の鳥類が確認され,両地域で共通なのは20種であった.しかし,コゲラ,エナガ,ヤマガラおよびシジュウカラの4種はA区で,コジュケイ,キジバト,アカショウビン,ツバメ,ヒヨドリ,ウグイス,ホオジ店スズメおよびハシブトガラスの9種はB区でそれぞれ高い相対密度(羽/ha)を示した.4)A区における上位4優占種の組み合わせは,ヒヨドリ-シジュウカラ-エナガ-ヤマガラであり,B区のヒヨドリ-スズメ-ウグイス-ホオジロ群集や水俣の照葉樹林帯(KUBO 1978)と異なるが,霧島山の荒襲•狭野地域のそれと類似する(黒田ほか1972).5)水俣で見られた鳥類のうち,コサメビタキ,イカル,ツツドリ,アオバズク,オオアカゲラなどは鳥帽子岳では見られず,キビタキ,オオルリなどの密度は後者で非常に低かった.一方,ヒヨドリの優占度が高く,林縁棲鳥類であるウグイスやホオジロ,都市部でも見られるスズメ,ツバメ,カワラビワなどが混じるなど,植栽林とそれに広葉樹林が混在する環境を反映した鳥相構成を顕著に示していると思われた
著者
東條 一史
出版者
The Ornithological Society of Japan
雑誌
日本鳥学会誌 (ISSN:0913400X)
巻号頁・発行日
vol.45, no.3, pp.141-158,195, 1996-12-25 (Released:2007-09-28)
参考文献数
30
被引用文献数
30 31

アオサギ亜科はサギ科最大のグループで(HANCOCK & KUSHLAN 1984),高緯度地域を除き全世界に分布している.観察が比較的容易なため,早くから繁殖生態や採餌行動の研究が進み(MEYERRIECKS 1960, 1962, KUSHLAN 1976, HANCOCK & KUSHLAN 1984など),また数種がコロニーや採餌場所を共有することが多いため,群集生態学的方面からも比較研究がなされてきた(JENNI1969,WILLARD 1977, RECHER & RECHER 1980など).しかし,採餌生態の比較研究の多くは北米に集中してきており,日本ではあまり行われていない.また,近年日本におけるチュウサギの減少が指摘されているが(中村 1984, 成末 1992, 環境庁1991), 有効な保護管理策を講じるには採餌生態の理解が不可欠である.ここでは,日本産のアオサギ亜科のサギ類,アオサギ Ardea cinerea,ダイサギ Egretta alba modesta, チュウサギ E.intermedia, コサギ E.garzetta, アマサギ Bubulcus ibis, の生息場所利用,採餌行動,餌利用を調べ,北米との類似性とチュウサギの減少理由について論じる.調査地は,千葉県の小櫃川河口付近の干潟,河川,農耕地を含む地域(Fig.1)である.調査は,センサスと個体観察によって1985年から1987年にかけての2年間行った.センサスは干潟,河川,農耕地のそれぞれに設けた調査区で月4回行い,個体観察は,採餌中の個体を継続的に5分以上観察し,餌内容と行動を記録した.採餌水深はサギのふしょ長,餌の人きさは嘴の長さと比較して推定した(Table 1).調査地では,5種のサギは比較的似通った個体数変動を示した.12月から5月までは比較的少なく,6,7月にかけて著しい増加,10,11月に著しい減少を示した(Fig.2).コサギは冬期でも一定数が見られたが,アマサギはごく少数が越冬しただけだった.アオサギは採餌場所として干潟と河川をよく利用し,ダイサギは干潟に多かった(Fig.3).チュウサギ,コサギ,アマサギはいずれも農耕地に多かった.また,ダイサギとコサギは,干潟,河川,農耕地を比較的どこでも利用したのに対し,アオサギの農耕地利用及びアマサギの干潟,河川の利用はほとんどみられず,チュウサギも農耕地以外の利用はあまりなかった,干潟と河川で採餌する場合,アオサギ,ダイサギは,チュウサギ,コサギより深い場所で採餌する傾向があった(Fig.4).農耕地では,ダイサギ,チュウサギ,コサギが水田,蓮田,休耕田など,水のある環境を主な採餌場所にしていたのに対し,アマサギは,あぜや草地など乾燥した場所で主に採餌し(Fig.5),水田で採餌する場合でもチュウサギやコサギより水の少ない田を選んだ(Fig.6).採餌行動は,アオサギは待ち伏せ(Standing)法を主に用い,ダイサギはゆっくり歩き(Walking Slowly)法も用いた(Fig.7).チュウサギはゆっくり歩き法と待ち伏せ法を主とし,コサギは速歩き(Walking Quickly)法を主とする活発な採餌行動を示した.アマサギはゆっくり歩き法が主だったが,チュウサギより活発な採餌を行った.コサギはチュウサギに比べ,採餌中のつつきの頻度は高かったが,成功率は低かった(Table 2).アオサギ,ダイサギ,チュウサギ,コサギは,いずれも干潟では魚類が主な餌だった.農耕地では,ダイサギとコサギはドジョウやアメリカザリガニを捕食し,チュウサギはその他にカエルと昆虫も利用した.アマサギは,昆虫類の利用が多かった(Table 3),コサギとアマサギは,微小な餌を数多く利用していた.干潟では,アオサギ,ダイサギ,チュウサギ,コサギの順に有意に大きな餌を捕食していた(Fig.8).これらの結果から,アオサギは本来広い水界へ,アマサギは陸環境へ,チュウサギは湿地へ特殊化してきたものと推察される.一方,ダイサギは広い水界,コサギは湿地的環境をよく利用するが,この2種は非特殊化者として様々な生息場所を利用できる.アオサギとダイサギおよびチュウサギとコサギは,それぞれ体の大きさと生息場所利用が似ているが,採餌行動と餌利用には違いが見られた.北アメリカでの研究(JENNI 1969,WILLARD 1977,RECHER & RECHER l980)と比較して,アオサギ,チュウサギ,コサギは,それぞれオオアオサギ Ardea herodias, ヒメアカクロサギ Egretta caerulea, ユキコサギ E.thula と似たニッチを占めている.ダイサギとアマサギは日本と北米両方に分布し,両地域で同じニッチを占めている.アオサギとオオアオサギおよびコサギとユキコサギはそれぞれ近縁である(CURRY-LINDAHL 1971,HANCOCK & KUSHLAN 1984)が,チュウサギとヒメアカクロサギの関係は明らかでない.DNA交雑法による解析(SHELDON 1987,SIBLEY& AHLQUIST 1990)では,チュウサギとヒメアカクロウサギは近縁でなく,また,ダイサギの北米の亜種 E.a.egretta と日本の亜種 E.a.modesta も別系統であることが示唆されている.
著者
Naoki Tomita Yuichi Mizutani Philip N Trathan Yasuaki Niizuma
出版者
The Ornithological Society of Japan
雑誌
ORNITHOLOGICAL SCIENCE (ISSN:13470558)
巻号頁・発行日
vol.14, no.1, pp.3-11, 2015 (Released:2015-02-18)
参考文献数
46
被引用文献数
8

Various seabird foraging strategies during the non-breeding season have recently been revealed by combining the use of bio-logging devices and the study of stable isotopic signatures (δ15N and δ13C) from various tissues. In this study, we used these combined methods to determine the relationships between stable isotopic signatures in Black-tailed Gulls Larus crassirostris primary feathers and the areas in which the feathers are presumed to have been grown. The fifth primary (P5) feathers are replaced during late August, and although the migratory movements for seven of the eight gulls studied during this replacement period differed, the isotopic δ15N and δ13C values were similar. These values indicated that the seven gulls fed on a wide range of prey from krill to demersal fish species. The isotopic values from P5 for the individual gull that moved southward after breeding, were much higher than for the seven other birds. In contrast, all eight gulls showed a relatively narrow distribution during the replacement of their outermost primaries (P10), which were replaced during mid October and November. However, the isotopic values from P10 of the individual that moved southward during replacement of P5 were also much higher. The unique isotopic values of this gull might indicate specialization in anthropogenic food resources or high trophic level resources through the migration period, regardless of location. Contrary to previous studies, our research did not detect links between migratory movements and stable isotopic signatures from feathers in Larus gulls migrating through a relatively narrow range and having considerable individual variation in diet.
著者
玉田 克巳
出版者
The Ornithological Society of Japan
雑誌
日本鳥学会誌 (ISSN:0913400X)
巻号頁・発行日
vol.53, no.2, pp.93-97, 2004 (Released:2007-09-28)
参考文献数
25
被引用文献数
8 7

Sexual differences of Carrion Corvus corone orientalis and Jungle crows C. macrorhynchos japonensis were examined. Crows were captured by 'multi-trap' during April 1989 to June 1990 in Ikeda, eastern Hokkaido. Body mass, bill length, natural wing length, tail length, and tarsus length of carcasses were all measured. They were aged by tongue-markings and dissected in order to examine their reproductive organs. They were classified into two age-classes (adults and juveniles). Males were larger than females in all measurements for adults and juveniles of both species. Discriminant function analysis was carried out. The probability of correct discrimination of sexes for Carrion Crows was 87% for adults and 80% for juveniles. For Jungle Crows it was 91% for adults and 92% for juveniles. The sexes of both adult and juvenile Jungle Crows could be determined by discriminant function analysis.