Owls play crucial roles in the environment and provide ecosystem services making them important to monitor and study. However, standardized methods for most species do not exist, and we lack understanding of the effects of many environmental variables and call-broadcast on detection of owls during surveys. We performed a multispecies occupancy analysis of owl monitoring data collected from 2004 to 2013 across the state of Maine to examine the effects of environmental variables, conspecific and heterospecific call-broadcast, and general survey protocols on detection of 3 forest owls: Northern Saw-whet Owl (Aegolius acadicus), Barred Owl (Strix varia), and Great Horned Owl (Bubo virginianus). We found that environmental variables such as cloud cover, precipitation, temperature, time of night, and wind had species-specific effects on detection probability, and ambient noise decreased detection probability for all species. Snow cover did not affect detection of any species. We also found that conspecific call-broadcast increased detection of each species, while heterospecific call-broadcast had variable effects. Specifically, we found that Long-eared and Barred owl broadcast increased the detection of Northern Saw-whet Owl, and our results suggest additional heterospecific effects may exist. Our study showed that, compared to the protocol of the Maine Owl Monitoring Program, surveys simultaneously examining all 3 of our focal species can increase efficiency and lower disturbance by only broadcasting Long-eared and Barred owl calls during a 10-min survey. We recommend that future owl surveys take into account species-specific effects of conspecific and heterospecific call-broadcast, and use our results when designing survey protocols that include one or more of our focal species.

中文翻译：

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标准化调查期间东部森林猫头鹰的环境条件和广播广播影响检测

猫头鹰在环境中起着至关重要的作用，并提供生态系统服务，因此它们对于监测和研究非常重要。但是，对于大多数物种而言，尚无标准化的方法，而且我们在调查过程中缺乏对许多环境变量和广播广播对猫头鹰检测的影响的理解。我们对缅因州从2004年至2013年收集的猫头鹰监测数据进行了多物种占用分析，以检查环境变量，同种和异种呼叫广播以及常规调查协议对3种森林猫头鹰的检测的影响：Northern Saw-whet猫头鹰（Aegolius acadicus），条纹猫头鹰（Strix varia）和大角O（Bubo virginianus）。我们发现，环境变量（如云量，降水，温度，夜间和风）对检测概率具有特定于物种的影响，而环境噪声降低了所有物种的检测概率。雪盖不会影响任何物种的发现。我们还发现，同种异型呼叫广播增加了对每个物种的检测，而异种异型广播则具有不同的影响。具体来说，我们发现长耳猫头鹰和猫头鹰猫头鹰广播增加了对北方锯齿猫头鹰的检测，我们的结果表明可能存在其他异种效应。我们的研究表明，与缅因州猫头鹰监测计划的协议相比，在10分钟的调查中，通过同时广播长耳和条纹猫头鹰的叫声，同时检查我们所有3个重点物种的调查可以提高效率并降低干扰。我们建议未来的猫头鹰调查应考虑同种和异种呼叫广播对物种的特定影响，并在设计包括一个或多个我们重点物种的调查协议时使用我们的结果。