Avian population ecology and functional connectivity in managed forest landscapes

归根结底，自然资源管理会影响个体生物体。人们通常认为，流动物种的个体会简单地转移到其他地方，以避开新干扰的地区，但很少有研究证实这一点。2006年，我们建立了一套试验田，我们标记了几乎所有的雄性候鸟物种(燕鸟)，然后在第二年冬天对其中一半的试验田进行选择性收获。这种采收处理去除了30%-40%的木材体积。自那以后，我们一直在监测燕子鸟种群和单独标记的雄性鸟的反应。我们还监测了棕色爬行动物的反应，这是另一种森林鸟类，是研究区域内常年居住或短途迁徙的物种。令人惊讶的是，在收获后的第一年，雄性燕雀返回它们的领地的人数几乎与对照组一样多。然而，4年后，2006年队列中的鸟类在试验区的比例仍然低于对照组。我们将继续进行这项研究，以回答以下问题：(1)2006年的燕雀在试验区的死亡率是否高于对照组？(2)如果是这样，移民是否保持了试验区的燕鸟密度？(3)这些候鸟大致来自哪个地区？(4)棕色爬行动物和燕子鸟的繁殖成功是否随着捕食者数量的增加而波动，并最终随种子生产周期的变化而波动？(5)这些现象是否受到收获处理的影响？这两种鸟类目前都不是稀有物种，但它们都对其范围内的森林敏感。因此，这项研究将提供至关重要的信息，以确保设计积极的保护战略，以维持这些物种和生态相似物种的健康种群。如果我们要解决生物多样性丧失的根本原因，预防性研究应该得到与物种恢复同样多的关注。到目前为止，我们的工作已经影响到了N.B.的森林管理政策，特别是确定了具有高度保护价值的森林的特征。

Ultimately, natural resource management influences individual organisms. It is often assumed that individuals of mobile species will simply move elsewhere to avoid newly-disturbed areas but few studies have been conducted to confirm this. In 2006, we established a set of experimental plots and we marked nearly all males of a migratory bird species (Ovenbird) prior to the treatment of half of these plots through selection harvesting during the next winter. This harvest treatment removed 30-40% of the wood volume. We have monitored the response of Ovenbird populations and individually-marked males ever since. We have also monitored the response of the Brown Creeper, another forest bird species that is a year-round resident or short-distance migrant in the study region. Surprisingly, in the first year after harvesting, almost as many male Ovenbirds returned to their territory as in the controls. However, 4 years after, a lower proportion of birds from the 2006 cohort are still present in treated plots than in controls. We will pursue this research to answer the following questions: (1) have the 2006 Ovenbirds suffered a higher mortality in treated plots than in controls? (2) If so, does immigration maintain the density of Ovenbirds in treated plots? (3) What is the approximate region from which these immigrants come from? (4) Does the reproductive success of the Brown Creeper and the Ovenbird fluctuate with the abundance of nest predators and, ultimately, in response to cycles in seed production? (5) Are these phenomena influenced by the harvest treatment? Neither of these bird species is currently rare but both are sensitive to forestry across their range. This research will thus provide information that will be critical to ensure that proactive conservation strategies are designed to maintain healthy populations of these and ecologically-similar species. Preventive research should receive as much attention as species recovery if we are to address the ultimate causes of biodiversity loss. So far, our work has influenced N.B. forest management policy, specifically to characterize forests of high conservation value.