We can't all excel at everything, or expect that Lewis and Clark would. Skilled as they were at describing mammals and plants their bird descriptions were more uneven. Some birds were so thoroughly described that it is impossible to make a false identification. The poorer descriptions, though, make identifying some birds uncertain. There were also the mistaken identities. Lewis saw one water bird and decided it was a loon-it wasn't. Clark figured another bird was a gull, and it wasn't.
Nonetheless, they sufficiently described over 50 species of birds. Some birds were new to science and others that were known got their geographic ranges extended. Their references to the passenger pigeon and Carolina parakeet placed the ranges of the two well beyond the Mississippi River, the previous known limit. The California condor, or 'buzzard' as they liked to call it, is today found exclusively in warm, dry climates around the Grand Canyon and in southern California. Reading from the journals of Lewis and Clark we learn that this magnificent bird was common along the cool, damp Oregon and Washington coast. Adding to their triumphs, they did manage to get one western bird back to Washington alive, the raucous, black-billed magpie!
Greater 19th century ornithologists were to follow with the likes of Alexander Wilson and James Audubon, yet Lewis and Clark gave us the first glimpse of bird diversity west of the Mississippi River.