By Jeff Reiter
An extinct bird, the passenger pigeon, is getting lots of attention this year. I'm good with that and hope you are, too. Every so often we need to pause from the "joy of birding" and think about the serious stuff.
Extinction is about as serious as it gets, and 100 years ago marked the end of the line for Martha, the world's last passenger pigeon. She died in the Cincinnati Zoo on Sept. 1, 1914. The story of Martha and her doomed species is well told in "A Feathered River Across the Sky," a new book by Joel Greenberg. The author chronicles how the most abundant bird species in North America dropped from 4 billion birds to none in 50 years. That seems impossible, but it really happened.