Henry Van Dyke quotation

["Cramer, Jeff" <Jeff.Cramer@walden.org>]

I was contacted by someone who thought that the quotation below was by Henry
David Thoreau. I learned that it was not Thoreau but is attributed to Henry
Van Dyke. However, I am unable to find the exact source of the quotation. If
anyone can help, it would be greatly appreciated. Many thanks in advance.
"Use what talent you possess: the woods would be very silent if no birds
sang except those that sang best." 
-Henry Van Dyke 
Jeffrey S. Cramer
Curator of Collections, The Thoreau Institute
        The Thoreau Institute is a collaborative effort 
of the Walden Woods Project and the Thoreau Society
44 Baker Farm, Lincoln, MA  01773-3004
Tel: (781) 259-4730  /  Fax: (781) 259-4710
E-mail: Jeff.Cramer@walden.org