"The story of Martha the passenger pigeon elicits both nostalgia and remorse for Cincinnati, the city that protected this bird, the last of her species, in a place where conservation is key . . . But now, these wistful tales are evolving. More Marthas may be on the way. Credit a new field of science called de-extinction biology. A group of scientists in Sausalito, California, are working on bringing back the passenger pigeon as part of a larger effort to enhance biodiversity through new techniques of genetic rescue of both endangered and extinct animals . . . The de-extinction efforts underway don't really re-create the bird's entire DNA. Instead, scientists start by decoding DNA from extinct passenger pigeons and, through bio-technology, change the DNA code of living band-tailed pigeons to match the passenger pigeon's code. By changing enough of the code, and through tried-and-true conservation practices, scientists hope the new birds look and behave the same way that their historic counterparts did."