Collision with power lines is a major cause of mortality for many bird species. Understanding the biotic and abiotic factors that increase collision risk is therefore important for implementing mitigation measures to minimize mortality, such as power line rerouting or wire marking. Here, we used collision events registered during 2003–2015 along 280 km of transmission power lines in southern Portugal to analyse spatio-temporal patterns and collision risk factors in two sympatric, threatened, and collision-prone species: the great bustard Otis tarda and the little bustard Tetrax tetrax. The occurrence of collisions was not uniform across space and time, and variations could be explained by the species' ecological requirements, distribution patterns and behaviour. Although both species fly considerable distances between areas of suitable habitat, collisions were far more likely in power line sections with > 20% (for the little bustard) or > 50% (for the great bustard) of open farmland habitat in the surroundings. Power line configuration was also important: taller pylons and those with a higher number of wire levels posed a higher risk for both species. Wire marking had a small but significant effect for the little bustard, reducing collisions risk. There was, however, no similar effect for the great bustard, possibly a result of limited data. Mitigation measures should be implemented to prevent bustard collisions, including adequate route planning, ideally avoiding areas with > 20% of open habitat. Line configuration and wire marking are particularly important where such localities cannot be avoided and power lines cross areas with a high proportion of bustard habitat, including outside protected areas.

中文翻译：

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电力线布线和配置是两种鸨类碰撞风险的主要驱动因素

与电线碰撞是许多鸟类死亡的主要原因。因此，了解增加碰撞风险的生物和非生物因素对于实施缓解措施以最大限度地降低死亡率非常重要，例如电力线重新布线或电线标记。在这里，我们使用 2003 年至 2015 年期间在葡萄牙南部 280 公里输电线路上记录的碰撞事件来分析两种同域、受威胁和易发生碰撞的物种的时空模式和碰撞风险因素：大鸨奥的斯和小鸨四联四联. 碰撞的发生在空间和时间上并不均匀，变化可以通过物种的生态需求、分布模式和行为来解释。尽管这两个物种在合适的栖息地区域之间飞行了相当长的距离，但在周围有> 20％（对于小鸨）或> 50％（对于大鸨）的开阔农田栖息地的电力线部分，碰撞的可能性要大得多。电源线配置也很重要：较高的塔架和电线数量较多的塔架对这两个物种构成更高的风险。电线标记对小鸨的影响很小但很显着，降低了碰撞风险。然而，对大鸨没有类似的影响，这可能是数据有限的结果。应采取缓解措施以防止鸨碰撞，包括充分的路线规划，最好避开开放栖息地 > 20% 的区域。线路配置和电线标记在无法避开此类地点且电力线穿过鸨栖息地比例较高的区域（包括保护区外）时尤为重要。