I returned to Pine County this morning with Richard Peet, we were after the elusive singing of two species, Pine Grosbeak and Northern Shrike. We found that since our CBC in the area on the 12/29, the Grosbeaks have exploded in population. We went to one feeder house on Townline road well east of Kerrick where we saw a flock of 30 Pine Grosbeaks and 7 Evening Grosbeaks. I have never been able to see the plumage variation in such detail or in such variety? By using my Sibley text, I attempted to discern which subspecies I was seeing. The males I saw mostly fit into the interior west race, with the gray mottling extending well up the breast. Two were a striking russet color, orange red; Sibley doesn't do it justice, as in most of the orange hues in the book. The color is more of an orange buffy, hard to describe. These birds are probably first year males. No singing, many call notes mixed with Evening Grosbeaks sharply trilled calls, redpolls chirruping and chortling, and a beautiful male Purple Finch. There were more than 100 birds actively feeding for most of the day. Shrikes were not to be found this day, but we will return, I read a paper yesterday postulating that the winter song of the Northern Shrike has a singular purpose - to lure in passing passerines to their destruction, a siren song so to speak. Both sexes sing in this way and there is conjecture that the loose phrases of its song are mimicry of alarm calls for birds they have been around. I have heard the song twice in my life, both birds were perched high in treetops, appearing to hunt. The softness of the warbling reminded me of a whisper song, definitely not the full volume you would expect from such a large passerine. I think this is fascinating, and cannot wait to record it. I wonder if they sing more often than we think, but we in cars do not hear it? If anyone finds a bird that is singing and regularly found, please post it so we can try and get it recorded before it returns to its Tundra homeland. And the next time you see a Northern Shrike perched high, surveying the territory, try and get in ear shot of it so you can witness this amazing behavior. The complexity of the birds we see every day never fails to impress,=20
Mark Alt=20 Brooklyn Center, MN=20 [email protected]=20 "Birds and their songs are important to me, they add to my enjoyment of life"=20
