Ex-Adaptation (TOEFL SPEAKING TASK4)

Article: The topic of article is "ex-adaptation", which is an evolutionary term refers to that a new function could be developed based on an existing function.
Lecture: There is a kind of bird in Africa which has long legs. They usually walk in the pond and they'll swallow water and eat fishes during daytime. They can't see the fish because of the reflection of the sunshine. So they'll raise their wings which are normally used for flying above their head as umbrella to block out the sunshine and create a shade. Therefore they can see the fish.