We had a rather brisk start to the morning on Saturday but were well compensated by a great variety and number of birds.  The South Platte is a bit too shallow for some of our local diving ducks as they seem to prefer the big deep reservoirs, so we missed a few of those, but nevertheless we had thirteen duck species – six dabbling ducks and seven divers.  When you look in your field guide the dabblers always proceed the divers.  It was interesting to note that while most of the ducks have acquired their breeding plumage, some of the Northern Shovelers still looked a bit scruffy.  The other dabblers all looked exceptionally beautiful and ready for breeding season.  We took particular pleasure in viewing the slender and elegant Northern Pintails with their light blue-gray and black bills.  Beautisimous!  

As for the divers there were two of special notice.  First, the number of Hooded Mergansers we saw was phenomenal.  They are certainly among our most spectacular ducks with the male and female both sporting incredible crests, and we saw scores of them.  Secondly, we got to see a beautiful male Barrow’s Goldeneye.  This was a SPECIAL sighting!  These guys are rare In Colorado.  They have a disjointed breeding range in North America – small populations exist in Iceland and Ontario, but 90% are found west of the Rocky Mountains, with northern Colorado representing their southernmost extension.  In Colorado breeding has only been documented in recent decades in the vicinity of the Flat Tops and at Echo Lake on Mount Evans.  There are more widely spread historical records prior to 1900.  In the winter in Colorado, and during both fall and spring migration, Barrow’s Goldeneyes are seen rarely on the reservoirs and rivers of the western valleys, in the mountain parks, and the eastern plains near the foothills.

What else?  While American Pipits breed commonly in the alpine tundra, they become uncommon during spring and fall migration, and in the winter can become downright rare, occurring occasionally on bare shorelines and gravel bars of ice-free rivers.  We were fortunate to see one at a distance out on a gravel bar, strutting around with its characteristic head jerking and tail bobbing.  As with the American Pipit, Black-crowned Night-Herons are a common breeder in Colorado, but they also become relatively uncommon in the winter, occurring primarily along rivers.  One of the places where they can regularly be found in winter is close to the Denver Waste Treatment Plant.  The warm effluent keeps the river open, and evidently creates an environment rich in those foods that Black-crowned Night-Herons love – leeches, earthworms, aquatic and terrestrial insects, crayfish, snails, clams, fish, amphibians, turtles, and various plants.  We counted 14 Night-Herons immediately upstream of the effluent.  Additional evidence that the effluent creates a special localized environment having a good insect community was evidenced by our seeing six insectivorous Yellow-rumped Warblers in the same area.

The numbers and range of Common Grackles, historically an Eastern species, has increased dramatically over the past one hundred years, including here in Colorado.  This increase can be ascribed to conversion of Eastern forests to agriculture, expansion of agriculture across the Great Plains, and the planting of islands of shelterbelts across the Great Plains.  These changes have created an avenue for expansion for the Grackle, and it is now one of the most successful and widespread species in North America.  We did not see any Common Grackles on Saturday, but we did see a species that’s been severely impacted by them.  With their arrival, Breeding Bird Survey data indicates a significant decline in Brewer’s Blackbirds, which used to be common throughout eastern Colorado.  We were fortunate to find a flock out on the Platte’s gravel bars.

Is that enough highlights for you?  Well, last but not least, we saw and heard two Greater Yellowlegs foraging along the edge of the river.  This species breeds across central Canada and we generally think of them as one of the many shorebirds that migrate through Colorado each year on their way going back and forth to southern Texas and further south.  To see one Greater Yellowlegs, or in our case two, in mid-winter is a rare occurrence, and generally mind-blowing!

Enough for now!  Go birding!  
Chuck

South Platte at 78th and 64th Ave, Jan 8, 2022
38 species

280 Canada Goose
8 Cackling/Canada Goose
750 Northern Shoveler
450 Gadwall
95 American Wigeon
90 Mallard
74 Northern Pintail
75 Green-winged Teal
6 Ring-necked Duck
40 Lesser Scaup
33 Bufflehead
49 Common Goldeneye
1 Barrow’s Goldeneye
74 Hooded Merganser
38 Common Merganser
3 Pied-billed Grebe
1 Rock Pigeon (Feral Pigeon) 
2 Eurasian Collared-Dove
200 American Coot
4 Killdeer
2 Greater Yellowlegs
48 Ring-billed Gull
33 Double-crested Cormorant
2 Great Blue Heron
14 Black-crowned Night-Heron
1Northern Harrier
4 Bald Eagle
5 Red-tailed Hawk
1 Hawk spp
3 Belted Kingfisher
19 Black-billed Magpie
6 Black-capped Chickadee
34 European Starling
1 American Pipit
12 White-crowned Sparrow
9 Song Sparrow
36 Red-winged Blackbird
24 Brewer’s Blackbird
6 Yellow-rumped Warbler