To which are added a few which still exist, but are on the verge of extinction.) is a book by Walter Rothschild which covers globally extinct and rare birds, as well as hypothetical extinct species which include bird taxa whose existence is based only on written or oral reports or on paintings.
To which are added a few which still exist, but are on the verge of extinction.) adalah sebuah buku karya Walter Rothschild yang membahas burung-burung pundah dan langka serta spesies punah hipotetikal yang meliputi taxa burung yang keberadaannya hanya berdasarkan pada laporan lisan atau lukisan.