Do agricultural sites provide high quality habitat for declining grassland songbirds?

整个北美的草原鸟类数量急剧下降，这些下降主要是由区域栖息地的丧失和农业集约化导致的退化造成的。一个关键的问题是，如何改善农业景观中的栖息地质量，使不断减少的草原鸟类受益？很少有研究测试不同的农业栖息地如何影响繁殖成功。还迫切需要研究草原鸣禽在农业景观中的栖息地选择，无论是在筑巢期间还是之后，以更好地了解栖息地质量如何影响繁殖的雌性。此前的研究因无线电跟踪鸣禽的高昂费用和困难而受到阻碍。我们正在研究萨凡纳麻雀(Passerculus Sandwichensis)，这种麻雀分布在加拿大和美国的奎尔夫附近。2016年，在Engage的资助下，我们监测了10个来自集约化农业地点的巢和26个来自自然地点的巢，发现在这些截然不同的栖息地筑巢成功是相似的。男性和女性的成年体重在农业和非农业地点之间也没有显著差异。我们还使用创新的新技术(MOTUS自动遥测阵列)来远程跟踪繁殖后成虫的扩散和栖息地选择，跨越数十公里，直到秋季迁徙。安大略省西南部数十座接收塔中的任何一座，当它们飞行在5-10公里范围内时，带有唯一编码纳米标签的鸟类会被自动探测到。2016年，我们在农业场所对14名成年人进行了标记，在自然场所对18人进行了标记；移动数据将于2017年2月提供用于分析。我们将使用地理信息系统对景观特征进行分析，以监测繁殖后的栖息地选择，并测试筑巢栖息地是否会影响秋季迁徙的时间。通过在2017年继续这项研究，增加样本量并测试年间影响(2016年是干旱年)，我们的研究将确定哪些农业生境最能维持草原鸟类数量的下降。预计这将为农民带来管理建议。

Grassland birds are in steep decline throughout North America and these declines are caused mainly byregional habitat loss and degradation as a result of agricultural intensification. A key question is how canhabitat quality be improved in agricultural landscapes to benefit declining grassland birds? Few studies havetested how different agricultural habitats impact the breeding success. There is also an urgent need to studyhabitat selection of grassland songbirds in agricultural landscapes, both during and after nesting, to betterunderstand how habitat quality affects breeding females. Prior studies have been hampered by the high expenseand difficulty of radio-tracking songbirds. We are studying Savannah Sparrows (Passerculus sandwichensis), adeclining species in Canada and the U.S, near Guelph, ON. In 2016, funded by ENGAGE, we monitored 10nests from intensive agricultural sites and 26 from natural sites and found that nesting success was similar inthese vastly different habitats. Adult body mass was also not significantly different between agricultural andnon-agricultural sites for both males and females. We are also using innovative new technology (MOTUSautomated telemetry array) to remotely track the dispersal and habitat selection of post-breeding adults overtens of kilometers and up until the point of fall migration. Birds radiotagged with uniquely coded Nanotags areautomatically detected when they fly within 5-10 km of any of the dozens of receiver towers in southwesternOntario. In 2016 we tagged 14 adults in agricultural sites and 18 in natural sites; movement data will beavailable in Feb 2017 for analysis. We will use GIS analysis of landscape features to monitor post-breedinghabitat selection, and test if nesting habitat carries over to affect timing of fall migration. By continuing thisstudy in 2017, to increase sample sizes and to test for between-year effects (2016 was a drought year) ourresearch will identify which agricultural habitats can best sustain declining populations of grassland birds. Thisis expected to lead to management recommendations for farmers.