11.   Peterson could identify birds by hearing them as well or better than he could by looking at them.

12.   Peterson was among the first to grasp the potential for a book that would help people identify birds while they were still alive.

13.   The offending birds were identified as yellow-shafted flickers, a common woodpecker in eastern North America that displays such behavior during courtship and to proclaim its territory.

14.   When they got back to their station in Houston two hours later, they showed the videotape to someone at the station who identified the bird as a killdeer.

15.   The library has lots of books that will help you identify the birds that you spot.