Context: Forest fire activity is expected to increase in many parts of the globe over the course of the 21st century, with corresponding potential for heightened levels of proximate and ultimate threats to avian diversity. Landscape-scale investigations of the responses of birds in locations where current extreme fire regimes represent those expected in the future provide opportunities to identify potentially vulnerable species in advance. Autonomous acoustic recorders are well suited to survey birds in the typically large and remote natural areas with low accessibility required for these types of studies, because they offer cost-effective and relatively safe options for obtaining reliable data.

Aims: The present study aimed to optimise survey using acoustic recorders to achieve a satisfactory assessment of montane dry sclerophyll forest bird assemblages using these devices. Survey completeness, or the number of species detected as a percentage of total species, was used as a metric to gauge survey suitability.

Methods: Acoustic recorders were deployed in 10 ridge-top forest sites in the Blue Mountains, south-eastern Australia. Extensive field recordings were processed by an analyst, with species detected by their calls recorded in a series of 20-min samples. A results-based approach, incorporating a stopping rule that established when to conclude sampling at a site, was applied to the data. The results guided the target survey completeness and sampling effort levels assigned to a set of fixed-effort survey methods, which were subsequently evaluated.

Key results: The optimal survey method involved using recordings from five 20-min sampling periods immediately following dawn for 2 days, achieving an average survey completeness level of 69%.

Conclusions: The optimal survey method can obtain results that are suitable for many types of studies involving assessments of bird assemblages, because the method can detect all common and moderately common species in assemblages, plus a fair proportion of rare species.

Implications: The present study has systematically developed an effective method of using autonomous acoustic recorders to research and monitor montane bird assemblages in fire-prone dry sclerophyll forests. This methodological approach may also be applied in systems subject to altered patterns of flood, storm or other extreme weather under climate change.

背景：预计在21世纪，全球许多地区的森林火灾活动都会增加，并具有潜在的威胁，加剧对鸟类多样性的直接威胁和最终威胁。在当前的极端火灾情况代表未来可能发生的火灾的地区，对鸟类的反应进行景观规模的调查，可以提前发现潜在的脆弱物种。自主声记录器非常适合在这类研究所需的通达性较低的典型大自然地区和偏远自然地区中调查鸟类，因为它们为获取可靠数据提供了经济高效且相对安全的选择。

目的：本研究旨在优化使用声波记录器的调查，以使用这些设备对山地干燥的硬叶林森林鸟类进行满意的评估。调查的完整性或检测到的物种数量占总物种的百分比被用作衡量调查适用性的指标。

方法：在澳大利亚东南部的蓝山山脉的10个山顶森林地点部署了录音机。分析师对大量的现场记录进行了处理，并通过呼叫将检测到的物种记录在一系列20分钟的样本中。基于结果的方法结合了停止规则，该规则建立了何时结束现场采样的时间，并应用于数据。结果指导了目标调查的完整性和分配给一组固定工作量调查方法的抽样工作量，随后对其进行了评估。

关键结果：最佳调查方法涉及使用从黎明后2天开始的五个20分钟采样时间段中的记录，使平均调查完整性水平达到69％。

结论：最佳调查方法可以获得适合于涉及鸟类聚集评估的许多类型研究的结果，因为该方法可以检测出聚集中的所有常见和中度常见的物种，以及相当比例的稀有物种。

启示：本研究系统地开发了一种有效的方法，该方法可以使用自动录音机来研究和监测易火的干燥硬叶森林中的山地鸟类群。这种方法论方法也可以应用于在气候变化下洪水，暴风雨或其他极端天气模式发生变化的系统中。