Emergent wetlands have declined in North America and, in response, many wetland-dependent animals have declined in abundance. For example, many species of secretive marsh birds in North America have declined during the last century. However, estimates of population decline and efforts to assess the effects of management actions are hampered because marsh birds are difficult to detect using conventional survey techniques. Call-broadcast surveys can improve detection probability of marsh birds; however, the effectiveness of call-broadcast varies regionally for some marsh birds, which might reflect differential responsiveness to call dialects. Here, we evaluated differential responses by least bitterns (Ixobrychus exilis) and clapper rails (Rallus crepitans) to different call dialects by using 679 paired call-broadcast surveys in Florida and South Carolina. We detected similar numbers of least bitterns and clapper rails responding to the different call dialects, except in Florida, where least bitterns responded more frequently to a more-distant (Louisiana) dialect than a more-local (Florida) dialect. Our results suggest that, at least for clapper rails and least bitterns, it may not be necessary to incorporate regional call dialects into standardized surveys. However, additional research is needed in more regions of North America and with other species.

北美新兴湿地数量有所减少，因此，许多依赖湿地的动物数量大量减少。例如，在上个世纪，北美许多隐秘的沼泽鸟类种类都在减少。但是，人口减少的估计以及评估管理措施效果的努力受到阻碍，因为使用常规调查技术很难检测出沼泽鸟类。呼叫广播调查可以提高对沼泽鸟类的发现概率；但是，对于某些沼泽鸟类，呼叫广播的效果因地区而异，这可能反映了对呼叫方言的不同响应。在这里，我们通过最少的盐卤（Ixobrychus exilis）和拍板导轨（Rallus crepitans）评估了差异响应），通过在佛罗里达州和南卡罗来纳州进行的679项配对呼叫广播调查对不同的呼叫方言进行定位。我们检测到响应不同呼叫方言的数量最少的卤水和拍手轨数量相近，但在佛罗里达州除外，佛罗里达州的卤水对较远的（路易斯安那）方言的响应比本地的（佛罗里达）方言的响应更为频繁。我们的结果表明，至少对于拍板声轨和最少的卤水，可能没有必要将区域性呼叫方言纳入标准化调查中。但是，在北美的更多地区以及其他物种中，还需要进行其他研究。