Department of Biology and Marine Biology, University of North Carolina at Wilmington, 601 South College Road, Wilmington, NC, USA.
Ecotoxicology. 2011 Jan;20(1):218-25. doi: 10.1007/s10646-010-0573-1. Epub 2010 Nov 17.
The objective of this study was to increase our understanding of Hg exposure in birds with obligate ties to coastal salt marsh and inland wetland systems. Many species filling such niches are of conservation concern because of reduced size and quality of vital habitats. We used Nelson's Sparrow (Ammodramus nelsoni) as an indicator of regional mercury (Hg) availability in its breeding and wintering salt marsh and wetland habitats. Blood, breast feathers and the first primary feather were sampled from Nelson's Sparrows wintering in North Carolina coastal salt marshes and breeding in wetland systems in North Dakota (A. n. nelsoni) and Ontario, Canada (A. n. alterus). Wintering Nelson's Sparrow breast feathers contained 3.0 times as much Hg as birds breeding in North Dakota and 2.4 times as much Hg as those breeding in Ontario. Breeding Nelson's Sparrows in North Dakota exhibited blood Hg levels 4.9 times as high as those from birds breeding along James Bay and 7.6 times as high as those wintering in North Carolina. These results provide significant insight on the timing of molt in this species as well as how Hg exposure varies regionally and seasonally for these birds. Further, our results provide a better understanding of how and where Hg exposure may be a threat to Nelson's Sparrows and other birds with obligate ties to aquatic systems.
本研究旨在增进我们对与沿海盐沼和内陆湿地系统有紧密联系的鸟类中汞暴露的了解。由于重要栖息地的面积和质量缩小，许多填补这些生态位的物种引起了人们的关注。我们使用纳尔逊麻雀（Ammodramus nelsoni）作为其在繁殖和越冬的盐沼和湿地栖息地中区域汞（Hg）可用性的指标。从北卡罗来纳州沿海盐沼越冬的纳尔逊麻雀和在北达科他州（A. n. nelsoni）和加拿大安大略省（A. n. alterus）的湿地系统繁殖的纳尔逊麻雀中采集血液、胸羽和第一初级飞羽。越冬的纳尔逊麻雀胸羽中的汞含量是在北达科他州繁殖的鸟类的 3 倍，是在安大略省繁殖的鸟类的 2.4 倍。在北达科他州繁殖的纳尔逊麻雀血液中的汞含量是在詹姆斯湾繁殖的鸟类的 4.9 倍，是在北卡罗来纳州越冬的鸟类的 7.6 倍。这些结果为该物种换羽的时间提供了重要的见解，以及这些鸟类的汞暴露如何在区域和季节性上有所不同。此外，我们的结果还更好地了解了汞暴露如何以及在何处可能对纳尔逊麻雀和其他与水生系统有紧密联系的鸟类构成威胁。
