Regional climate on the breeding grounds predicts variation in the natal origin of monarch butterflies overwintering in Mexico over 38 years
Regional climate on the breeding grounds predicts variation in the natal origin of monarch butterflies overwintering in Mexico over 38 years
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DOI：
10.1111/gcb.13589
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发表时间：
2017-07-01
影响因子：
11.6
通讯作者：
Norris, D. Ryan
中科院分区：
文献类型：
--
作者：
Flockhart, D. T. Tyler;Brower, Lincoln P.;Norris, D. Ryan
解决迁飞昆虫种群数量下降的问题需要将种群在年周期的不同部分联系起来，并了解天气和气候变化对生产力，招聘和长距离移动模式的影响。我们使用稳定的H和C同位素和地理空间建模来估计北美东部帝王蝶（Danaus plexippus）的纳塔尔起源，使用近四十年来在墨西哥越冬殖民地收集的1000多只帝王蝶。多项式回归被用来确定哪些气候相关因素最好的预测时间变化的纳塔尔起源在六个繁殖区。美国中西部是越冬帝王蝶数量最多的地区（平均年比例= 0.38; 95% CI：0.36-0.41）其次是中北部（0.17; 0.14-0.18）、东北（0.15; 0.11-0.16）、西北（0.12; 0.12-0.16）、西南（0.11; 0.08-0.12）和东南（0.08; 0.07-0.11）区域。没有证据表明随着时间的推移，不同纳塔尔地区的相对贡献发生了方向性变化，这表明近年来这些地区在越冬种群中的相对比例与20世纪70年代中期相同。相反，年际变化的比例，从每个地区的君主与气候变化，测量的南方涛动指数和区域特定的每日最高温度和降水量，这可能共同决定幼虫的发育速度和粮食植物条件。我们的研究结果提供了第一个强大的长期分析预测的纳塔尔起源的君主在墨西哥越冬。集中在中西部地区的繁殖地的保护工作可能会对北美东部的迁徙君主产生最大的好处，但种群可能会对区域和随机天气模式保持敏感。
Addressing population declines of migratory insects requires linking populations across different portions of the annual cycle and understanding the effects of variation in weather and climate on productivity, recruitment, and patterns of long-distance movement. We used stable H and C isotopes and geospatial modeling to estimate the natal origin of monarch butterflies (Danaus plexippus) in eastern North America using over 1000 monarchs collected over almost four decades at Mexican overwintering colonies. Multinomial regression was used to ascertain which climate-related factors best-predicted temporal variation in natal origin across six breeding regions. The region producing the largest proportion of overwintering monarchs was the US Midwest (mean annual proportion = 0.38; 95% CI: 0.36-0.41) followed by the north-central (0.17; 0.14-0.18), northeast (0.15; 0.11-0.16), northwest (0.12; 0.12-0.16), southwest (0.11; 0.08-0.12), and southeast (0.08; 0.07-0.11) regions. There was no evidence of directional shifts in the relative contributions of different natal regions over time, which suggests these regions are comprising the same relative proportion of the overwintering population in recent years as in the mid-1970s. Instead, interannual variation in the proportion of monarchs from each region covaried with climate, as measured by the Southern Oscillation Index and regional-specific daily maximum temperature and precipitation, which together likely dictate larval development rates and food plant condition. Our results provide the first robust long-term analysis of predictors of the natal origins of monarchs overwintering in Mexico. Conservation efforts on the breeding grounds focused on the Midwest region will likely have the greatest benefit to eastern North American migratory monarchs, but the population will likely remain sensitive to regional and stochastic weather patterns.