近几十年来,城市安娜蜂鸟的喙已经进化得更长更大,以便更好地获取安装在住宅外的含糖饮水器,这种饮水器在城市地区大量存在。
In recent decades, the beaks of city Anna hummingbirds have evolved (to be) longer and larger, so as to better access the sugar water in the feeders mounted outside the dwellings, a device widely available in urban areas. (or, which are abundant in urban areas.)