...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Ecological Applications >Grassland songbirds in a dynamic management landscape: Behavioral responses and management strategies
【24h】

Grassland songbirds in a dynamic management landscape: Behavioral responses and management strategies

机译：动态管理环境中的草原鸣禽：行为响应和管理策略

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

In recent decades, earlier and more frequent harvests of agricultural grasslands have been implicated as a major cause of population declines in grassland songbirds. From 2002 to 2005, in the Champlain Valley of Vermont and New York, USA, we studied the reproductive success of Savannah Sparrows (Passerculus sandwichensis) and Bobolinks (Dolichonyx oryzivorus) on four grassland treatments: (1) early-hayed fields cut before 11 June and again in early- to mid-July; (2) middle-hayed fields cut once between 21 June and 10 July; (3) late-hayed fields cut after 1 August; and (4) rotationally grazed pastures. Both the number of fledglings per female per year and nest success (logistic-exposure method) varied among treatments and between species. Although birds initiated nests earlier on early-hayed fields compared to others, haying caused 99% of active Savannah Sparrow and 100% of active Bobolink nests to fail. Both the initial cutting date and time between cuttings influenced renesting behavior. After haying, Savannah Sparrows generally remained on early-hayed fields and immediately renested (clutch completion 15.6 +/- 1.28 days post-haying; all values are reported as mean +/- SE), while Bobolinks abandoned the fields for at least two weeks (mean clutch completion 33 +/- 0.82 days post-haying). While female Savannah Sparrows fledged more offspring per year (1.28 +/- 0.16) than female Bobolinks (0.05 +/- 0.05), reproductive success on early-hayed fields was low. The number of fledglings per female per year was greater on middle-hayed fields (Savannah Sparrows, 3.47 +/- 0.42; Bobolinks, 2.22 +/- 0.26), and late-hayed fields (Savannah Sparrows, 3.29 +/- 0.30; Bobolinks, 2.79 +/- 0.18). Reproductive success was moderate on rotationally grazed pastures, where female Savannah Sparrows and female Bobolinks produced 2.32 +/- 0.25 and 1.79 +/- 0.33 fledgling per year, respectively. We simultaneously conducted cutting surveys throughout the Champlain Valley and found that 3-8% of hayfield habitat was cut by 1-4 June, 25-40% by 12-16 June, and 32-60% by 28 June-2 July. Thus, the majority of grassland habitat was cut during the breeding season; however, late-hayed fields served as high-quality reserves for late-nesting female Bobolinks that were displaced from previously bayed fields. For fields first cut in May, a 65-day interval between cuts could provide enough time for both species to successfully fledge young.
机译：在最近的几十年中，早先和更频繁地收获农业草原被认为是草原鸣禽种群减少的主要原因。从2002年到2005年，我们在美国佛蒙特州和纽约州的尚普兰河谷研究了Savannah Sparrows（Passerculus sandwichensis）和Bobolinks（Dolichonyx oryzivorus）在四种草地处理方法上的繁殖成功：（1）在11之前砍伐的早干草田六月，七月初至七月中旬; （2）在6月21日至7月10日之间，将干草田割掉一次; （3）8月1日以后砍伐的干草田; （4）旋转放牧的牧场。每只雌性每年的雏鸟数量和巢成功率（后勤暴露方法）在不同处理之间和物种之间都不同。尽管与其他人相比，鸟类在较早干草田里筑巢的时间更早，但干草使99％的活跃萨凡纳麻雀和100％的主动Bobolink巢失败。初始切割日期和切割之间的时间都会影响嵌套行为。干草后，Savannah Sparrows通常仍留在早干草田上，并立即重新嵌套（干草完成后离合器完成15.6 +/- 1.28天;所有值均报告为平均值+/- SE），而Bobolinks放弃了田地至少两周（在干草后33 +/- 0.82天的平均离合器完成时间）。尽管雌性大草原麻雀每年繁殖的后代（1.28 +/- 0.16）比雌性Bobolinks（0.05 +/- 0.05）多，但早干草田的繁殖成功率很低。在中干草田（Savannah Sparrows，3.47 +/- 0.42; Bobolinks，2.22 +/- 0.26）和晚干草田（Savannah Sparrows，3.29 +/- 0.30; Bobolinks），每只雌性每年的雏鸟数量更多，2.79 +/- 0.18）。旋转放牧的牧草的繁殖成功率中等，雌性大草原麻雀和雌性Bobolinks每年分别产生2.32 +/- 0.25和1.79 +/- 0.33的雏鸟。我们同时在整个尚普兰河谷进行了割草调查，发现到6月1-4日割草了3-8％，到6月12-16日割草了25-40％，到6月28日-7月2日割了32-60％。因此，在繁殖季节大部分草原生境被砍伐。但是，干草后田地为从先前海湾田间迁离的晚巢雌性Bobolinks提供了高质量的储备。对于5月首次砍伐的田地，两次砍伐之间有65天的间隔，可以为两个物种提供足够的时间使它们成功成年。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号