1. They're pretty close to the ground, but these warblers also nest in forests that have low shrub density. 它们离地面很近，但是这些蓝莺也会在灌木密度低的森林里面筑巢。
2. The confirmation researchers had been seeking was finally achieved in studies involving two varieties of warblers. 在对两种莺的研究中，研究人员一直在寻找的证据最终得到了证实。
3. The young of ground-nesting warblers produce begging cheeps of higher frequencies than do their tree-nesting relatives. 相比在树上筑巢的同种类雏鸟，在地面筑巢的鸣禽雏鸟会发出频率更高的乞食叫声。
4. It is usually the younger warblers that nest in these areas because the preferred spots where there are a lot of shrubs are taken by the older, more dominant birds. 通常，年轻的蓝莺将会在这些地方筑巢，因为有浓密灌木的首选的筑巢点已经被更年长的、地位更高的蓝莺所占领了。
5. The evidence suggests that warblers use their extremely elaborate songs primarily to attract females, clearly confirming the effect of intersexual selection on the evolution of birdsong. 证据表明，莺主要用它们极其精致的歌声吸引雌性，这清楚地证实了雌雄间选择对鸟类鸣叫进化的影响。
