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

整个北美草原鸟类数量急剧下降，主要是由于农业集约化导致的区域栖息地丧失和退化造成的。一个关键的问题是如何改善农业景观的栖息地质量，以使日益减少的草原鸟类受益？很少有研究测试不同的农业栖息地对繁殖成功的影响。为了更好地了解生境质量对雌性繁殖的影响，迫切需要研究农业景观中草地鸣鸟筑巢期间和筑巢后的栖息地选择。先前的研究受到无线电追踪鸣禽的高成本和困难的阻碍。我们正在研究萨凡纳麻雀（Passerculus sandwhensis），这是加拿大和美国在安大略省圭尔夫附近濒临灭绝的物种。2016年，在ENGAGE的资助下，我们监测了集约化农业地点的10个巢穴和自然地点的26个巢穴，发现这些截然不同的栖息地的筑巢成功率相似。男性和女性的成人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（motu自动遥测阵列）远程跟踪繁殖后成虫的分布和栖息地选择，距离长达数十公里，直到秋季迁徙。在西北地区的几十个接收塔附近，当鸟儿飞到5-10公里范围内时，带有独特编码纳米标签的无线电标签就会被自动检测到。2016年，我们在农业场所标记了14个成虫，在自然场所标记了18个；移动数据将于2017年2月提供分析。我们将利用地理信息系统分析景观特征来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效应（2016年是干旱年），我们的研究将确定哪些农业栖息地最能维持草原鸟类数量的下降。这有望为农民提供管理建议。

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.