The influence of weather and habitat fragmentation on plant and insect phenology, arrival times and breeding success of boreal birds

北美候鸟繁殖区由于人类的使用而变得越来越分散，鸟类也必须应对气候变化。气候变暖预计在高纬度地区最强烈，因此北方鸟类可能受到最大的影响。由于森林小气候受斑块大小和周围森林覆盖的影响，更恶劣的天气条件和较小斑块中昆虫食物的减少可能会降低冬季居民的存活率。然而，在春季，碎片可能会提前升温，植物和昆虫物候提前，昆虫更多，因此中等大小的斑块在春季和夏季可能是高质量的。在这些片断之间的相互作用下，天气、小气候和物候以及它们对破碎景观中种群持久性的影响还没有得到很好的研究。本建议的主要目的是：1.确定斑块大小和周围森林覆盖对冬夏季小气候、植物物候、昆虫物候和丰度的影响。2.将这些因素与冬季生存和身体状况以及繁殖季节食物状况和留鸟(山雀、毛雀、啄木鸟)的繁殖成功联系起来。3.将这些因素与移民的抵达时间、领土选择和生殖成功联系起来。4.确定春季气温和极端天气事件对抵达繁殖区北部环志站点的候鸟性别和年龄比例的关系。

Breeding areas for resident and migrant birds in North America are becoming increasingly fragmented by human use and birds must also cope with changing climate.  Climate warming is predicted to be most intense at high latitudes, hence, boreal birds may be most affected.  Since forest microclimate is affected by patch size and surrounding forest cover, harsher weather conditions and lower amounts insect food in smaller patches may reduce survival of winter residents.  However, in spring, fragments may warm up earlier, have earlier plant and insect phenology and more insects, hence medium sized patches may be of high quality in spring and summer.  These interactions between fragmentation, weather and microclimate and phenology and the impacts of these on population persistence in fragmented landscapes have not been well studied.  The main objectives of this proposal are to: 1. Determine the influence of patch size and surrounding forest cover on micro-climate, plant phenology, insect phenology and abundance in winter and summer. 2. Relate these factors to winter survival and body condition and to breeding season food conditions and reproductive success of resident birds (chickadees, nuthatches, woodpeckers). 3. Relate these factors to arrival times, territory choice and reproductive success of migrants. 4. Determine the relationship of spring temperature and extreme weather events on sex and age ratios of migrant birds arriving at banding stations in the northern parts of the breeding range.