Dear Jansy,
“Peterson’s grouse” is a reference to the
late Roger Tory Peterson, the author of the long-time standard guide
to North American Birds. There is no “Peterson’s Grouse, however.
Alan P. Peterson’s book is long post-VN.
Long ago,I published an article
entitled, I vaguely recall, “The Birds in Nabokov’s Ad”a in an obscure
Festshrift for Dean S. Worth.
Best, Don