Departamento de Ecología Evolutiva, Museo Nacional de Ciencias Naturales (CSIC), Madrid, Spain.
PLoS One. 2012;7(3):e32569. doi: 10.1371/journal.pone.0032569. Epub 2012 Mar 1.
Collision with electric power lines is a conservation problem for many bird species. Although the implementation of flight diverters is rapidly increasing, few well-designed studies supporting the effectiveness of this costly conservation measure have been published.
METHODOLOGY/PRINCIPAL FINDINGS: We provide information on the largest worldwide marking experiment to date, including carcass searches at 35 (15 experimental, 20 control) power lines totalling 72.5 km, at both transmission (220 kV) and distribution (15 kV-45 kV) lines. We found carcasses of 45 species, 19 of conservation concern. Numbers of carcasses found were corrected to account for carcass losses due to removal by scavengers or being overlooked by researchers, resulting in an estimated collision rate of 8.2 collisions per km per month. We observed a small (9.6%) but significant decrease in the number of casualties after line marking compared to before line marking in experimental lines. This was not observed in control lines. We found no influence of either marker size (large vs. small spirals, sample of distribution lines only) or power line type (transmission vs. distribution, sample of large spirals only) on the collision rate when we analyzed all species together. However, great bustard mortality was slightly lower when lines were marked with large spirals and in transmission lines after marking.
Our results confirm the overall effectiveness of wire marking as a way to reduce, but not eliminate, bird collisions with power lines. If raw field data are not corrected by carcass losses due to scavengers and missed observations, findings may be biased. The high cost of this conservation measure suggests a need for more studies to improve its application, including wire marking with non-visual devices. Our findings suggest that different species may respond differently to marking, implying that species-specific patterns should be explored, at least for species of conservation concern.
与电力线碰撞是许多鸟类物种的保护问题。尽管飞行转向器的实施正在迅速增加，但很少有经过精心设计的研究支持这种昂贵的保护措施的有效性。
方法/主要发现：我们提供了迄今为止全球最大规模标记实验的信息，包括在总计 72.5 公里的 35 条（15 条实验，20 条对照）电力线上进行的尸体搜索，这些电力线包括输电（220 kV）和配电（15 kV-45 kV）线路。我们发现了 45 个物种的尸体，其中 19 个是保护关注的物种。发现的尸体数量经过校正，以考虑因食腐动物清除或研究人员忽视而导致的尸体损失，估计每月每公里每公里有 8.2 次碰撞。与标记前相比，我们观察到实验线路中的标记后伤亡人数略有（9.6%）但显著减少。在对照线路中没有观察到这种情况。当我们一起分析所有物种时，我们发现标记的大小（大螺旋与小螺旋，仅分布线路样本）或电力线类型（输电与配电，仅大螺旋样本）对碰撞率没有影响。然而，在标记后，大鸨的死亡率在使用大螺旋和输电线路标记时略低。
我们的结果证实了电线标记作为减少但不能消除鸟类与电线碰撞的有效方法。如果不通过食腐动物清除和错过观察导致的尸体损失来校正原始野外数据，研究结果可能存在偏差。这种保护措施的高成本表明需要进行更多的研究来改进其应用，包括使用非视觉设备进行电线标记。我们的研究结果表明，不同的物种可能对标记有不同的反应，这意味着至少对于保护关注的物种，应该探索特定物种的模式。
