Abstract Farmland bird populations have experienced severe declines across Europe and elsewhere. Agricultural intensification is believed to be a main factor behind these declines, with losses of non-cropped features, such as farmland ponds, identified as a key driver. Since the 1950s, many European farmland ponds have been in-filled or, through lack of management, become terrestrialised. Restoring terrestrialised farmland ponds has been shown to significantly increase the abundance and diversity of local farmland bird communities. It has been hypothesised that farmland birds are specifically attracted to open-canopy ponds due to increased emergent aquatic insect availability, but this link has hitherto been little explored. This study investigates how farmland pond management influences emergent aquatic insects, and how emergent insect abundance and biomass is linked to local bird assemblages. Insect emergences showed an 18-fold higher abundance and a 25-fold higher biomass at managed open-canopy ponds in comparison to their unmanaged overgrown counterparts, with day-to-day fluctuations in pond water temperature a key predictor of insect emergences. Species richness and abundance of birds at farmland ponds were strongly positively linked to the abundance of emergent insects. Furthermore, insect emergence peaks occurred on different days in different restored ponds such that the pond landscape afforded extended feeding opportunities for birds. Our findings suggest that restoring networks of terrestrialised farmland ponds to open-canopy macrophyte-dominated conditions could be a highly effective way of increasing the availability of aquatic insect prey for birds. This study highlights an urgent need to re-evaluate pond restoration and management within agri-environmental schemes in Europe and beyond.

中文翻译：

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池塘作为昆虫烟囱：恢复杂草丛生的农田池塘通过提高新兴水生昆虫的生产力使鸟类受益

摘要 欧洲和其他地方的农田鸟类数量急剧下降。农业集约化被认为是这些下降背后的一个主要因素，农田池塘等非作物特征的丧失被确定为一个关键驱动因素。自 1950 年代以来，许多欧洲农田池塘已被填满，或者由于缺乏管理而变成陆地。恢复陆上农田池塘已被证明可以显着增加当地农田鸟类群落的丰度和多样性。据推测，由于新出现的水生昆虫的可用性增加，农田鸟类特别被开放式树冠池塘所吸引，但迄今为止，这种联系很少被探索。本研究调查农田池塘管理如何影响水生昆虫，以及新出现的昆虫丰度和生物量如何与当地鸟类组合相关联。与未管理的过度生长的对应物相比，管理的开放式树冠池塘中昆虫出现的丰度高 18 倍，生物量高 25 倍，池塘水温的日常波动是昆虫出现的关键预测因素。农田池塘鸟类的物种丰富度和丰度与涌现昆虫的丰度呈强烈正相关。此外，昆虫出现高峰出现在不同恢复的池塘中的不同日期，因此池塘景观为鸟类提供了延长的觅食机会。我们的研究结果表明，将陆生农田池塘网络恢复到开放式冠层大型植物占主导地位的条件可能是增加鸟类水生昆虫猎物可用性的一种非常有效的方法。这项研究强调了在欧洲及其他地区的农业环境计划中重新评估池塘恢复和管理的迫切需要。