The New Yorker website just now (I believe) posted this 2003 profile (by Dana Goodyear) of Kunitz, who died on Sunday.

I've been thinking about those rainforest appeals that warn, "Every five minutes, another animal becomes extinct." Everyone beloved is the last of his or her species gone from the earth. Stanley was a notably rare, exalted, humble animal unto himself, and with him extinct, the air seems thinner, the whole project sadder and less certain.