Drastic Declines in Brown Shrike and Yellow-Breasted Bunting at the Lake Utonai Bird Sanctuary, Hokkaido
Drastic Declines in Brown Shrike and Yellow-Breasted Bunting at the Lake Utonai Bird Sanctuary, Hokkaido
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北海道宇托内湖鸟类保护区的褐伯劳和黄胸鹀急剧减少
DOI：
10.2326/osj.16.51
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发表时间：
2017
影响因子：
0.6
通讯作者：
M. Tomizawa
中科院分区：
文献类型：
--
作者：
Katsumi Tamada;S. Hayama;Masatoshi Umeki;Masayuk Takada;M. Tomizawa
摘要：从 1982 年至 2002 年，日本野鸟协会位于北海道宇东内湖的鸟类保护区获得了鸟类的每日观测记录。我们分析了四种被认为正在经历数量下降的物种的每日记录：褐伯劳 Lanius cristatus、黑眉芦莺 Acrocephalus bistrigiceps、栗耳鹀 Emberiza fucata 和黄胸鹀 E. aureola。近二十年来，棕伯劳和黄胸鹀的检出率急剧下降，而黑眉芦莺和栗耳鹀的检出率则保持稳定。 2002年和2003年，我们进行了线断面普查，发现黄胸鹀数量极少，没有发现棕伯劳，而这两种鸟类在1977年之前还很丰富。年度观鸟调查积累的数据显示，这两个物种的数量也出现了类似的下降。这些观察表明，虽然棕伯劳在 20 世纪 80 年代初之前很常见，但在 1986 年急剧下降。黄胸鹀在 1997 年之前仍然很常见，但此后严重下降。从 1982 年到 2002 年，黑眉芦莺或栗耳鹀没有明显的趋势，尽管后者从 2011 年开始似乎有所下降。研究区域不太可能出现大规模栖息地破坏，因为在研究开始之前，该湖及其周边地区就已被指定为野生动物保护区。我们结合之前的研究讨论了潜在的原因。
Abstract Daily records of bird observations were obtained from the Wild Bird Society of Japan bird sanctuary at Lake Utonai, Hokkaido, from 1982 to 2002. We analysed the daily records of four species thought to be experiencing declines: Brown Shrike Lanius cristatus, Black-browed Reed Warbler Acrocephalus bistrigiceps, Chestnut-eared Bunting Emberiza fucata and Yellow-breasted Bunting E. aureola. The detection rates of Brown Shrike and Yellow-breasted Bunting declined drastically during the two decades, whereas the detection rates of Black-browed Reed Warbler and Chestnut-eared Bunting remained stable. In 2002 and 2003 we conducted line transect censuses, and detected very few Yellow-breasted Buntings and no Brown Shrikes, both of which had been abundant as recently as 1977. The accumulated data from annual bird watching surveys showed similar declines in the same two species. These observations suggest that whereas the Brown Shrike had been common prior to the early 1980s, it declined drastically in 1986. The Yellow-breasted Bunting remained common until 1997, but declined seriously thereafter. There were no clear trends for Black-browed Reed Warbler or Chestnut-eared Bunting from 1982 to 2002, although the latter appeared to decline from 2011 onwards. Large-scale habitat destruction is unlikely in the study area, since the lake and its surrounding area have been a designated a wildlife protection area since before the study began. We discuss potential causes, together with previous studies.