|
The black brant or Pacific brent goose (''Branta bernicla nigricans'') is a subspecies of the brant goose that breeds in Alaska and winters in Baja California. There are an estimated 115,000 black brant in the world and about 14,000 are taken each year by hunters. Fox predation of eggs is thought to be significant and, in 2006, the U.S. began a 5-year fox removal program. The population has been as high as 200,000 in 1981, and as low as 100,000 in 1987.〔(Slimbridge: Black Brant )〕 ==References== *Millington, Richard (1997). Separation of Black Brant, Dark-bellied Brent Goose and Pale-bellied Brent Goose ''Birding World'' 10(1):11–15; an identification paper *Syroechkovski, E. E., C. Zöckler and E.Lappo (1998). Status of Brent Goose in northwest Yakutia ''British Birds'' 93(2):94–97; this paper presented claims that Black Brant and Dark-bellied Brent Goose were interbreeding extensively in the Russian Arctic *Sangster, George (2000). Taxonomic status of ''bernicla'' and ''nigricans'' Brent Goose ''British Birds'' 91(12):565–572; a critical re-evaluation of the claims made in the above paper by Syroechkovski et al. *Bloomfield, Andrew and James McCallum (2001). Changing fortunes of the Black Brant ''Birding World'' 14(2):66–68; discusses the history of Black Brants in Europe, and the history of hybridisation between Black Brant and Dark-bellied Brent Goose *Martin, John (2002). From the Rarities Committee's files: Unusual Brent Geese in Norfolk and Hampshire ''British Birds'' 95(3):129–136; this article discusses two Brent Geese, seen in Norfolk and Hampshire in 1998/99, which showed some but not all characters of Black Brant; photographs of both accompany the article *Wynn, Russell (2002). Brants – the hybrid problem ''Birdwatch'' 118:16–18; an examination of possible hybrid Black Brant × Dark-bellied Brent Goose, based on wintering birds in Hampshire *(Black Brant Geese, an indicator of wildlife sustainability in the Georgia Basin ) Environment Canada. Retrieved October 10, 2006 fr:Bernache du Pacifique 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Black brant」の詳細全文を読む スポンサード リンク
|