Doctoral Dissertation Research: Spatial and Temporal Configurations of Potential Distributions of Grassland Sparrows

博士论文研究：草原麻雀潜在分布的时空配置

• 批准号: 1131644
• 负责人: Townsend Peterson
• 金额: $ 1.17万
• 依托单位: University of Kansas Center for Research Inc
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-07-15 至 2013-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1131644&HistoricalAwards=false
• 关键词: Doctoral; Dissertation; Research; Spatial; Temporal

One problem that has vexed biogeographers and others interested in the distribution of different species is the difficulties that many species have in adapting when their habitats are changed by human activity or other forces. A related problem is the difficulty in monitoring the number and distribution of these species. One such species is Henslow's sparrow (Ammodramus henslowii), a grassland-nesting bird that is found in the central U.S. and nearby parts of Canada. This doctoral dissertation research project will take a multifaceted view of Henslow's sparrow distributional biology, focusing on improving understanding about how populations respond to broad-scale habitat changes and of the extent to which human activities affect the amount and distribution of its breeding habitat, particularly in Midwestern grasslands. Henslow's sparrows currently have a distribution that is patchy and local; although the limits of the species' range are perhaps well-known, existing surveys are largely confined to roads. Current information therefore may neither represent all available habitat, such as grasslands in airfields, military bases, and reclaimed surface mines, nor does it accurately estimate population trends. No detailed map of suitable habitat for the full breeding distribution currently is available. The doctoral student will use ecological niche models to produce a detailed distributional understanding by identifying key environmental variables and characterizing the amount of suitable breeding habitat and its spatiotemporal dynamics within a patch-matrix framework while taking into account landscape heterogeneity and habitat patch characteristics produced by year-to-year disturbance dynamics. Once these models have been validated through independent field surveys, year-to-year variation of the extent and arrangement of suitable patches will be analyzed. This analysis will provide insight and explanation for the broad-scale nomadic behavior documented in earlier studies of the breed. These models also will be used to evaluate how well current survey techniques function to sample Henslow's sparrow breeding habitat. The student will evaluate these models by summarizing the amount of suitable grasslands in patches immediately surrounding routes identified by the North American Breeding Bird Survey and by comparing it to the broader distribution of this habitat (produced by the niche models) and the proportion of habitat types within the landscape matrix (using land-cover maps).Henslow's sparrows have very specific nesting habitat requirements that make them relatively good indicators of healthy tallgrass prairie ecosystems. Like many other obligate grassland species, they have suffered severe habitat loss as a result of fragmentation and conversion of grasslands, a loss estimated to have exceeded 99 percent across North America. Unlike a few other species that adapted easily to these changes, Henslow's sparrows have not responded well across their breeding range, and they have exhibited significant population declines over the last century. Recent studies have shown that this species does not return consistently to patches of habitat from year to year, which makes management of their habitat more difficult. This project will make significant contributions to the assessment of Henslow's sparrow populations and trends. The project also will provide a test of the capability of current survey techniques to effectively survey rare species and spatially limited habitat types. The project also will facilitate evaluation of recommendations for habitat management that more effectively accommodate the nomadic behavior as well as the amount, distribution, arrangement, or disturbance dynamics of this habitat at landscape scales. The results of this project therefore will potentially affect how species like Henslow's sparrows are managed and will prompt reevaluation of population trend estimates or habitat availability for other, similar species. As a Doctoral Dissertation Research Improvement award, this award also will provide support to enable a promising student to establish a strong independent research career.

有一个问题一直困扰着地理学家和其他对不同物种分布感兴趣的人，那就是当人类活动或其他力量改变了许多物种的栖息地时，它们很难适应。 一个相关的问题是难以监测这些物种的数量和分布。 其中一个物种是亨斯洛麻雀（Ammodramus henslowii），这是一种在美国中部和加拿大附近地区发现的草地筑巢鸟。 这个博士论文研究项目将采取亨斯洛的麻雀分布生物学的多方面的观点，重点是提高对人口如何应对大规模的栖息地变化和人类活动影响其繁殖栖息地的数量和分布的程度的理解，特别是在中西部草原。 亨斯洛麻雀目前的分布是不完整的和局部的;虽然该物种的范围的限制可能是众所周知的，现有的调查主要局限于道路。因此，目前的信息可能既不能代表所有可用的栖息地，如机场，军事基地和开垦的地表矿山的草地，也不能准确估计人口趋势。 目前还没有详细的适合整个繁殖分布的栖息地地图。 博士生将使用生态位模型，通过确定关键环境变量和表征合适的繁殖栖息地及其时空动态的斑块矩阵框架内的数量，同时考虑到景观异质性和栖息地斑块特征产生了详细的分布理解年到年的干扰动态。 一旦这些模型通过独立的实地调查得到验证，将分析适当斑块的范围和安排的逐年变化。 这项分析将提供洞察力和解释的大规模游牧行为记录在早期的研究品种。 这些模型也将被用来评估如何以及目前的调查技术功能，以采样亨斯洛的麻雀繁殖栖息地。 学生将通过总结北美繁殖鸟类调查确定的路线周围的合适草地数量，并将其与该栖息地的更广泛分布进行比较，来评估这些模型（生态位模型产生的）和景观矩阵中生境类型的比例（使用土地覆盖地图）。亨斯洛麻雀有非常具体的筑巢栖息地要求，这使它们成为健康高草草原生态系统的相对良好的指标。 像许多其他专性草原物种一样，由于草原的破碎和转换，它们遭受了严重的栖息地损失，估计整个北美的损失超过99%。 与其他几个容易适应这些变化的物种不同，亨斯洛麻雀在其繁殖范围内的反应并不好，在过去的世纪里，它们的数量出现了显著的下降。 最近的研究表明，该物种不会每年持续返回栖息地，这使得对其栖息地的管理更加困难。 该项目将为评估亨斯洛麻雀种群和趋势做出重大贡献。 该项目还将测试现有调查技术有效调查稀有物种和空间有限的生境类型的能力。 该项目还将促进评估栖息地管理的建议，更有效地适应游牧行为以及数量，分布，安排，或干扰动态的栖息地在景观尺度。 因此，该项目的结果可能会影响像亨斯洛麻雀这样的物种的管理方式，并将促使重新评估其他类似物种的种群趋势估计或栖息地可用性。 作为博士论文研究改进奖，该奖项还将提供支持，使有前途的学生建立一个强大的独立的研究生涯。