World Bird List

Species factsheet

Voices can be found here (external link)

Subspecies and Distribution

-Subspecie
+Distribution
-glacialis
+se Alaska (USA)
-medianus
+c Alaska to e Canada and c and e USA
-fumidus
+sw Canada and w Washington  (USA)
-gairdnerii
+w Oregon to nw California  (USA)
-turati
+c Washington to c California  (USA)
-leucurus
+Rocky Mts.  (se Alaska to sw USA)
-pubescens
+se USA