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

由于人类的使用，北美留鸟和候鸟的繁殖区正变得越来越分散，鸟类也必须应对不断变化的气候。据预测，气候变暖在高纬度地区最为强烈，因此，北方鸟类可能受到的影响最大。由于森林小气候受斑块大小和周围森林覆盖的影响，在较小的斑块中，恶劣的天气条件和较少的昆虫食物可能会降低冬季居民的存活率。然而，在春季，碎片可能更早升温，植物和昆虫物候更早，昆虫更多，因此中等大小的斑块在春夏可能质量较高。破碎化、天气小气候和物候之间的相互作用及其对破碎化景观中种群持久性的影响尚未得到充分研究。本建议的主要目标是：1。确定斑块大小和周围森林覆盖对冬季和夏季小气候、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的食物条件和留鸟（山雀、nuthatches、啄木鸟）的繁殖成功联系起来。3. 将这些因素与移民的到达时间、领土选择和繁殖成功率联系起来。4. 确定春季气温和极端天气事件对到达繁殖区北部带站候鸟性别和年龄比例的影响。

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.