Though it was a magnificently beautiful morning at Bear Creek Lake Park, we struggled to find birds – only two duck species and three sparrow species, and we missed such generally common birds as Downy Woodpecker and White-breasted Nuthatch. Nonetheless, the morning did have its highlights. We saw at least three subspecies of Red-tailed Hawk: the to-be-expected light western-morph with its creamy front and streaked belly-band, one intermediate-morph – likely a second-year bird given that it didn’t have the full adult rufous upper breast, and one Krider’s Hawk, or white-morph. This last only occurs rarely during migration in Colorado, and caution needs to be taken in making a definite identification as there can be occasional western-morphs that are very white. Our bird (which I personally didn’t see) was very pale, almost white underneath with obvious dark patagia (the leading edges of the wings), prominent dark “commas” at the edge of the primary underwing coverts, and dark tips on the primary flight feathers. It lacked any apparent belly-band. The tail had the same white coloration as the underbody, but the central rectrices (tail-feathers) were noticeably pale rufous.
We then spent quite a while working to identify a single light brown duck over 1000 feet away from us. What fun! From the beginning I thought it could be a Black Scoter while many participants were leaning towards Northern Shoveler. Turns out we were all wrong and it was a juvenile Ruddy Duck. But it took the persistence of one of our group, Anne Craig, to get on the other side of the reservoir and get a closer look to make that final determination. Now, this is not the first time I’ve struggled with telling juvenile Ruddy Ducks from juvenile Black Scoters. They can look extremely similar, though the scoter is larger and longer. The one clue that I didn’t take better advantage of was using a nearby Double-crested Cormorant for comparison. A cormorant is 33” long, a Black Scoter is 19”, and a Ruddy Duck is 15”. Both birds, as juveniles, are light gray-brown with dark caps and smudgy white cheeks. What we couldn’t discern from a distance was that our individual had the beginnings of a faint dark line across the cheek – diagnostic for Ruddy. Anyway, it was a good exercise in thinking that all had been worked out correctly only to discover that we were (I was) inaccurate in that first assessment.
Good birding!
Chuck
Bear Creek Lake Park, Oct 15, 2022
29 species
16 participants
Canada Goose 3
Mallard 2
Ruddy Duck 1
Rock Pigeon (Feral Pigeon) 2
Eurasian Collared-Dove 1
Mourning Dove 2
Killdeer 3
Ring-billed Gull 17
Double-crested Cormorant 80
American White Pelican 2
Great Blue Heron 2
Red-tailed Hawk 6 (1 intermediate morph and 1 Krider’s)
Belted Kingfisher 1
Northern Flicker 5
Black-billed Magpie 16
American Crow 1
Common Raven 1
Black-capped Chickadee 8
American Dipper 1
European Starling 40
Townsend’s Solitaire 1
American Robin 5
House Finch 8
American Goldfinch 3
White-crowned Sparrow 4
Song Sparrow 4
Spotted Towhee 4
Western Meadowlark 4
Red-winged Blackbird 40