Kalahari skinks eavesdrop on sociable weavers to manage predation by pygmy falcons and expand their realised niche.

Eavesdropping on community members has immediate and clear benefits. However, little is known regarding its importance for the organisation of cross-taxa community structure. Furthermore, the possibility that eavesdropping could allow species to coexist with a predator and access risky foraging habitat, thereby expanding their realised niche, has been little considered. Kalahari Tree Skinks (<i>Trachylepis spilogaster</i>) associate with Sociable weaver (<i>Philetairus socius</i>)<i> </i>colonies, as do African pygmy falcons (<i>Polihierax semitorquatus</i>), a predator of skinks and weavers. We undertook observational and experimental tests to determine if skinks eavesdrop on Sociable weavers to mitigate any increase in predation threat that associating with weaver colonies may bring. Observations reveal that skinks use information from weavers to determine when predators are nearby; skinks were more active, more likely to forage in riskier habitats and initiated flight from predators earlier in the presence of weavers, compared to when weavers were absent. Playback of weaver alarm calls caused skinks to increase vigilance and flee, confirming that skinks eavesdrop on weavers. Furthermore, skinks at Sociable weaver colonies were more likely to flee than skinks at non-colony trees, suggesting that learning is mechanistically important for eavesdropping behaviour. Overall, it appears that eavesdropping allows skinks at colony trees to gain an early warning signal of potential predators, expand their realised niche and join communities, whose predators may otherwise exclude them.<br><br><br><br><br>

窃听群落成员具有直接且明确的生态益处。然而，学界对其在跨类群群落结构组织中的关键作用却知之甚少。此外，窃听可使物种与捕食者共存并进入高风险觅食生境，进而拓展其实际生态位（realized niche）的可能性，也极少被相关研究关注。

卡拉哈里树石龙子（Kalahari Tree Skinks，*Trachylepis spilogaster*）会依附于群居织巢鸟（Sociable weaver，*Philetairus socius*）群落生存，而非洲侏儒隼（African pygmy falcons，*Polihierax semitorquatus*）——一种以石龙子和织巢鸟为食的捕食者——也会如此。

我们开展了观测与实验测试，旨在探明石龙子是否通过窃听群居织巢鸟的信号，来缓解依附织巢鸟群落时可能面临的捕食威胁提升。观测结果显示，石龙子会利用织巢鸟的相关信息判断捕食者是否临近：与无织巢鸟的场景相比，有织巢鸟存在时，石龙子的活动频次更高，更倾向于在高风险生境中觅食，且会更早地从捕食者附近逃离。播放织巢鸟的警戒叫声会促使石龙子提升警戒水平并发起逃离，这证实了石龙子确实会窃听织巢鸟的信号。进一步而言，群居织巢鸟群落周边的石龙子，比非群落树木上的石龙子更易做出逃离反应，这表明学习机制对窃听行为至关重要。总体而言，窃听似乎让依附群落树木的石龙子获得了针对潜在捕食者的早期预警信号，拓展了其实际生态位，并得以加入那些若没有该行为其捕食者可能会将其排除的群落。