近幾十年來,城市安娜蜂鳥的喙已經進化得更長更大,以便更好地獲取安裝在住宅外的含糖飲水器,這種飲水器在城市地區大量存在。
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.)