1. Effective evidence‐based conservation requires full quantification of the impacts of targeted management interventions on focal populations. Such impacts may extend beyond target individuals to also affect demographic rates of non‐target conspecifics (e.g. different age classes). However, such collateral (i.e. unplanned) impacts are rarely evaluated despite their potential to substantially alter conservation outcomes. Subsequent management decisions may then be poorly informed or erroneous.
2. We used 15 years of individual‐based demographic data in a ‘before‐after control‐impact’ (BACI) analysis to quantify collateral demographic impacts of a targeted multi‐year supplementary feeding programme designed to increase sub‐adult survival and hence viability of a small, threatened red‐billed chough Pyrrhocorax pyrrhocorax population. Specifically, we assessed whether the intervention also affected adult survival and reproductive success, and whether such collateral effects were themselves sufficient to stabilize population size and hence achieve short‐term conservation aims.
3. The probabilities of adult survival and successful reproduction increased substantially between the ‘before‐feeding’ and ‘during‐feeding’ periods in those choughs associated with supplementary feeding, but not otherwise. Overall breeding success (i.e. number of chicks fledged per occupied territory) also tended to increase, even though brood sizes did not increase. These relationships, which were detectible only through BACI analyses, suggest that supplementary feeding targeted at sub‐adults had unplanned positive impacts on adult demographic rates.
4. Deterministic matrix models designed to project population growth demonstrate that these estimated collateral effects were sufficient to make a substantial contribution to increasing population growth rate and achieving short‐term population stability.
5. Synthesis and applications. Our results indicate substantial positive collateral impacts of a targeted supplementary feeding intervention on population viability, despite no a priori expectation that the non‐target adults were food‐limited. This casestudy illustrates how thorough assessment of collateral impacts of targeted interventions can affect assessment of short‐term efficacy and reveal new opportunities for future interventions, thereby informing subsequent management decisions.

中文翻译：

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有针对性的补充喂养对人口统计学和受威胁人口的增长率的附带好处

1. 有效的基于证据的保护需要充分量化针对性管理干预措施对重点人群的影响。这种影响可能会超出目标个人，从而影响非目标人群的人口统计率（例如，不同的年龄段）。但是，尽管这种附带（即计划外）影响有可能实质性改变保护结果，但很少对其进行评估。随后的后续管理决策可能会被告知错误或错误。
2. 我们在“先于控制后影响”（BACI）分析中使用了15年的基于个人的人口统计学数据，以量化旨在提高亚成年生存率并因此提高成活率的目标性多年补充喂养计划的附带人口统计学影响。小，有威胁的红嘴山鸦Pyrrhocorax pyrrhocorax种群。具体而言，我们评估了干预措施是否也影响了成年生存和生殖成功，以及这种附带影响本身是否足以稳定种群规模并因此实现短期保护目标。
3. 在与补饲相关的食槽中，在“喂食前”和“喂食期间”之间，成年存活和成功繁殖的可能性大大增加，但没有增加。即使育雏数量没有增加，总体育种成功率（即在每个被占领地区出雏的雏鸡数量）也趋于增加。这些关系只有通过BACI分析才能发现，这表明针对次成年人的补充喂养对成人人口统计率产生了计划外的积极影响。
4. 设计用于预测人口增长的确定性矩阵模型表明，这些估计的附带影响足以为提高人口增长率和实现短期人口稳定做出重大贡献。
5. 综合与应用。我们的结果表明，尽管没有先验地认为非目标成年人的食物有限，但有针对性的补充喂养干预措施对种群生存能力具有实质性的积极影响。该案例研究说明了对有针对性的干预措施的附带影响进行全面评估如何影响短期疗效评估并揭示未来干预措施的新机会，从而为后续的管理决策提供依据。