Climate and food synchronize regional forest bird abundances
Climate and food synchronize regional forest bird abundances
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DOI：
10.1890/02-0639
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发表时间：
2003-11-01
期刊：
影响因子：
4.8
通讯作者：
Holmes, RT
中科院分区：
文献类型：
--
作者：
Jones, J;Doran, PJ;Holmes, RT
分析人口波动的同步性有助于确定调节人口的因素以及这些因素对人口产生影响的规模。利用美国新罕布夏州四个重复林区15年来鸣鸟丰度的数据，我们回答了两个主要问题：(1)在测量的范围内(几十公里)，森林鸟类种群是否同步，如果是，(2)是什么环境因素导致了这种同步？在我们研究的10种鸟类中，有9种在四个地点表现出显著的空间同步性。在筑巢和觅食种群中，树巢和采叶鸟表现出最高的空间同步性。长途(新热带)移民表现出比短途移民或常年居民更高的空间同步性。6种远距离迁徙食虫鸟类内部和之间的同步性与鳞翅目幼虫丰度的同步波动有关，鳞翅目幼虫是繁殖季节的主要食物类型，而这反过来又被证明受到厄尔尼诺/拉尼娜全球气候模式的影响。常年栖息物种的丰富与另一种大范围气候现象--北大西洋涛动有关。冬季天气对常年栖息物种既有直接影响(例如，通过温度调节的死亡)，也有间接影响(例如，通过冬季食物供应)。我们不认为对成虫或巢的捕食可以解释观察到的同步性。在这个系统中，区域种群之间的扩散可能起到了一定的作用，但很可能是区域同步毛虫波动对鸟类繁殖的影响的产物。长期的区域种群趋势可能有助于观察到某些物种的同步性，但我们不认为这些趋势是主要因素。我们关于种群同步性的发现支持了食物和气候在影响森林鸟类数量方面的重要性，并对鸟类和昆虫种群对气候变化的潜在反应具有广泛的影响。
Analysis of synchrony in population fluctuations can help to identify factors that regulate populations and the scales at which these factors exert their influence. Using 15 years of data on the abundances of songbirds at four replicate forest sites in New Hampshire, USA, we addressed two main questions: (1) Are forest bird populations synchronous at the scale measured (tens of kilometers), and if so, (2) what environmental factors are responsible for the synchrony? Nine of the 10 bird species we examined exhibited significant spatial synchrony across the four sites. Within nesting and foraging species groups, tree nesters and foliage gleaners exhibited the highest spatial synchrony. Long-distance (Neotropical) migrants exhibited higher spatial synchrony than did short-distance migrants or year-round residents. Synchrony within and among six species of long-distance, migratory, insectivorous birds was correlated with synchronous fluctuations in the abundance of lepidopteran larvae, a primary food type during the breeding season, which in turn have been shown to be influenced by El Nino/La Nina global climate patterns. Abundances of year-round resident species were related to another large-scale climatic phenomenon, the North Atlantic Oscillation. Winter weather can have both direct (e.g., via temperature-mediated mortality) and indirect (e.g., via winter food availability) effects on year-round resident species. We do not believe that predation on adults or nests accounted for the observed synchrony. Dispersal among regional populations in this system may have played a role but is likely a product of the influence of regionally synchronous caterpillar fluctuations on bird reproduction. Long-term regional population trends may have contributed to the observed synchrony for some species, but we do not consider these trends to be primary factors. Our findings of population synchrony support the importance of food and climate in influencing forest bird abundances and have broad implications for potential responses of bird and insect populations to climate change.