Mount Falcon: June 2, with Chuck Aid

Green-tailed Towhee (c) Bill Schmoker

It was a beautiful early summer morning up on top of Mount Falcon this past Saturday, June 2.  Eleven of us enjoyed a delightful stroll through the ponderosa woodlands, montane grassland, montane shrubland, and Douglas-fir forest. The mix of habitats on top of Mount Falcon is a wonderful mosaic, and consequently provides homes for a delightful variety of birds.

Cordilleran Flycatcher (c) Felice Lyons

So, since it’s breeding season, the birds were letting the world know which territory was whose, and we got to hear a lot of nice songs.  A pair of House Wrens was investigating a probable nesting cavity in a rotten snag, and between times singing up a storm from a nearby rock outcropping.   A Plumbeous Vireo kept loudly proclaiming his presence, which his apparent partner seemed to appreciate, and which we appreciated because it allowed us to track him down right in front of us at eye-level. At one point a Cordilleran Flycatcher was singing continuously right above us, and we all got multiple great looks. Because of all this singing we got so many great looks!  Western Tanagers, Gray-headed Juncos, and Green-tailed Towhees were also pretty non-stop. And, once we switched over into the more dense Douglas-fir Forest, we had a nice long visit with a singing Brown Creeper.

Wallflower (c) Chuck Aid

Oh, and the flowers were splendiferous!  The foothill flowers will be reaching their peak in the coming weeks so make sure to get out and enjoy them.  Hope to see you on another bird walk soon!

Chuck Aid

Mount Falcon Park, Jun 2, 2018
28 species

Turkey Vulture  1
Sharp-shinned/Cooper’s Hawk  1
Mourning Dove  1
Broad-tailed Hummingbird  8
Northern Flicker (Red-shafted)  2
Western Wood-Pewee  1
Cordilleran Flycatcher  1
Plumbeous Vireo  2
Steller’s Jay (Interior)  4
Black-billed Magpie  4
American Crow  8
Common Raven  2
Violet-green Swallow  4
Mountain Chickadee  4
White-breasted Nuthatch  3
Pygmy Nuthatch  4
Brown Creeper  2
House Wren  8
Western Bluebird  2
Hermit Thrush  1
American Robin  3
Chipping Sparrow  2
Dark-eyed Junco (Gray-headed)  5
Green-tailed Towhee  5
Spotted Towhee  1
Western Tanager  8
Black-headed Grosbeak  1
House Finch  1
Pine Siskin  3


Harriman Lake: May 12, with Chuck Aid

Tree Swallow (c) Bill Schmoker
Barn Swallow (c) Bill Schmoker

Saturday, May 12, as part of the Front Range Birding Company’s Annual Expo, we offered four different bird walks. Six of us went to Harriman Lake (Kipling & Quincy), and managed to tally 51 species.  As the early morning was humid and cool with a low cloud cover, one of the first things to greet us were hundreds and hundreds of swallows flying low over the lake and perching on the lower tree branches and cattails.  We later on got good looks at individual species, but that first onslaught was both miraculous and daunting.

Female Bufflehead (c) Bill Schmoker

One never knows at this time of year how many ducks to expect, as the majority of several species have already flown north by the middle of May.  We saw no Common Goldeneyes, but we did manage one pair of Ring-necked Ducks and one Hooded Merganser.  The most interesting observation regarding this group of May-migrants is that we saw 15 Bufflehead, but they were all females.  Apparently, the males have left already for the prairie provinces of Canada where they will be setting up territories – looking for ponds that have nearby trees with old woodpecker cavities which are attractive to such cavity nesters as Buffleheads.

Great Horned Owl juvenile (c) Bill Schmoker

Another fun sighting was of a mom Great Horned Owl with her two youngsters that are quickly approaching adult size. We got great looks, and they were totally at their ease.

The highlight of the morning was the great views we had of three Virginia Rails.  They came out into the open on several occasions and were actively calling much of the time.  I recommend that northwest side of Harriman where the trail is near the cattails.  It was in this same area that I saw an American Bittern last October.  We also had a Sora here on Saturday.

Hope to see you soon on another bird walk!

Virginia Rail (c) Bill Schmoker

Harriman Lake, May 12, 2018
51 species

Canada Goose  6
Blue-winged Teal  1
Northern Shoveler  2
Gadwall  18
Mallard  6
Redhead  11
Ring-necked Duck  2
Bufflehead  15
Hooded Merganser  1
Ruddy Duck  18
Pied-billed Grebe  7
Double-crested Cormorant  5

Sora (c) Bill Schmoker

Great Blue Heron  4
Great Egret  1
Turkey Vulture  9
Osprey  1
Swainson’s Hawk  1
Red-tailed Hawk  1
Virginia Rail  3
Sora  1
American Coot  46
Rock Pigeon (Feral Pigeon)  3
Eurasian Collared-Dove  2
Mourning Dove  11
Great Horned Owl  3
Northern Flicker  1
American Kestrel  1
Say’s Phoebe  1
Blue Jay  3
Black-billed Magpie  2
Tree Swallow  500 
Violet-green Swallow  700
Barn Swallow  25
Cliff Swallow  100
Black-capped Chickadee  1
House Wren  1
American Robin  8
European Starling  1
MacGillivray’s Warbler  1
Yellow Warbler  1
Clay-colored Sparrow 3
Lark Sparrow  2
Vesper Sparrow  1
Song Sparrow  5
Spotted Towhee  2
Yellow-headed Blackbird  1
Western Meadowlark  5
Red-winged Blackbird  70
Brown-headed Cowbird  1
Common Grackle  15
House Finch  6


Chatfield Bird-Banding: May 6, with Chuck Aid and Meredith McBurney

Meredith McBurney (c) Bird Conservancy of the Rockies

Twelve of us enjoyed a delightful morning – first checking out the birds at the feeders at the Denver Audubon Nature Center, and then visiting with Meredith McBurney as she banded a few birds at the Bird Conservancy of the Rockies’ banding station. The Conservancy has been banding birds at Chatfield in the spring and at Barr Lake in the fall for almost thirty years, and Meredith has played a major role in that endeavor. She is not only accomplished at what she does, but she has a multitude of interesting facts and stories to relate.

Common Yellowthroat (c) Bill Schmoker

These two banding stations, at Chatfield and Barr, have been located in places where migratory birds tend to congregate. Using mist nets, birds are harmlessly trapped, they’re removed from the nets, data is collected on them, a small, numbered band is placed on a leg, and then they’re released. Each of these bands has a unique number on it so that if the bird is recaptured somewhere else we can know where and when it was banded, thus learning a bit about the timing and route of that species’ migration. Here’s a link to a video of Meredith banding birds –




Rose-breasted Grosbeak (c) John Hoogerheide

Beyond our great visit with Meredith we ended up tallying 26 species (see list below). The morning was easily dominated by House Wrens everywhere. A few of our best sightings were of a singing Common Yellowthroat and, we also had great looks at a Green-tailed Towhee, an American Goldfinch, and a Lazuli Bunting. The real highlight though was a beautiful male Rose-breasted Grosbeak at the feeder at the Denver Audubon Nature Center. This is a rare to uncommon spring migrant on the eastern plains of Colorado, with only a couple of confirmed breeding records for the state.

Lazuli Bunting (c) Bill Schmoker

Chatfield Bird Banding Station, May 5
26 species

Mallard 2
Double-crested Cormorant 2
Bald Eagle 1
Mourning Dove 5
Broad-tailed Hummingbird 2
Say’s Phoebe 1
Tree Swallow 1
Cliff Swallow 3
Black-capped Chickadee 2
White-breasted Nuthatch 1
House Wren 14
Hermit Thrush 1
American Robin 6
European Starling 1
Common Yellowthroat 2
Yellow Warbler 1
Song Sparrow 4
Green-tailed Towhee 1
Spotted Towhee 6
Rose-breasted Grosbeak 1
Lazuli Bunting 1
Western Meadowlark 3
Red-winged Blackbird 18
Brown-headed Cowbird 4
House Finch 4
American Goldfinch 2

Hudson Gardens: March 31, 2018 with Jennifer O’Keefe & Chip Clouse

Our merry group of 27 birders ventured into Hudson Gardens and along the South Platter River on a brisk, beautiful day with plenty of sun. We spotted 25 species of birds during our 3-hour walk covering just under 2 miles.

We began by walking clockwise through Hudson Gardens, looking and listening for birds in the trees, on the ground, in the sky, and everywhere in between. American Robins and Red-winged Blackbirds were both observed singing out in the open, giving us a great opportunity to associate the song with the bird.

Out along the South Platte trail, we saw many of the waterbirds we’d anticipate seeing this time of year such as Bufflehead, American Wigeon, Green-winged Teal and Gadwall.

One exciting observation was a Northern Harrier behaving very un-Harrierlike. These medium-sized raptors with long tails and a distinctive white rump patch are most often seen flying low over grasslands or marshes. This behavior is explained by their habit of not only looking for its prey, but listening as well. The Northern Harrier we observed was soaring high in the sky, a behavior we typically expect from other raptors such as the Red-tailed Hawk. What a treat to see a bird exhibiting an unexpected behavior!

Female Northern Harrier @ Bill Schmoker

Another big highlight was a pair of nest-building Bushtits. These tiny gray birds are often seen in marauding flocks that descend upon your suet feeder and then disappear, often for weeks at a time. This time of year, they are paired up to nest and often start earlier than many other perching birds.

Bushtit @ Bill Schmoker

As spring migration continues, we will say goodbye to many species of waterbirds, and hello to some of our summer favorites such as hummingbirds, swallows, and Bullock’s Orioles. Be sure to sign up early for the next walk on April 28th, 2018 by visiting the Hudson Garden’s website.

Species List:

American Robin – 30

Black-capped Chickadee – 5

Northern Flicker – 3

European Starling – 9

Red-winged Blackbird – 25

Northern Harrier – 1

Song Sparrow – 4

Green-winged Teal – 4

Bufflehead – 7

Double-crested Cormorant – 2

Mallard – 14

American Coot – 1

House Finch – 12

American Goldfinch – 4

Killdeer – 1

Bushtit – 4

American Wigeon – 12

Gadwall – 6

Swallow spp. – 10 (flying high)

Canada Goose – 26

Blue Jay – 5

Common Grackle – 3

Eurasian Collared-Dove – 2

Common Raven – 1

Black-billed Magpie – 3

Harriman Lake, April 7, with Chuck Aid and David Chernack

To begin with, the weather was far milder than anticipated, the sun broke through the scattered clouds, and we ended up tallying 42 species of birds.  So, it was certainly a fantastic morning for the ten of us that showed up to greet the day and the birds.

Lincoln’s Sparrows are a relatively irregular sparrow in the Front Range. Our group was lucky enough to watch a small flock of eight foraging along the path just feet away. (c) David Chernack

Harriman Lake continues to be a very nice local hot spot for wintering and migratory waterfowl.  Some of these were not apparent on Saturday.  We saw no Western Grebes, no geese other than Canada, or any of the three teal species, and there were no American Wigeons, Canvasbacks, Redheads, or any of the three merganser species.  However, what we did see was pretty great!  To begin with we had three members of the Aythya genus: Ring-necked Duck, Lesser Scaup, and the more uncommon Greater Scaup.  In one of the early field books for Colorado birders Harold Holt and James Lane (first published, I believe, in 1987), instead of using terms such as “abundant” and “rare,” used expressions like “Hard to miss” or “May see.”  For Greater Scaup they said, “Lucky to find,” and we certainly counted ourselves as “lucky.”

Is there anything that says spring more than a warbler? This Yellow-rumped Warbler (Audubon’s subspecies) gave us great looks as it foraged in a lakeside cottonwood. (c) David Chernack

We had high numbers for Buffleheads (90) and Ruddy Ducks (45), earning us on eBird what I’ve come to call “the dreaded black box.”  If you use the eBird app to enter your bird lists you may know whereof I speak.  The black box appears whenever you record a species that’s unanticipated for your location, or if you enter a number in excess of what eBird thinks is reasonable for your location.  eBird then asks that you justify your sighting in some way, e.g. a good written description or a photograph of what you saw.  Justifying these dramatic changes in numbers can be particularly tricky during migration when good sized flocks can be present one day and gone the next.

A couple of other great sightings included fifteen Pied-billed Grebes and an Eared Grebe.  The Pied-bills seem to have a real affinity for Harriman, possibly based on the apparently abundant crayfish population, and they can be seen here year-round.  We often see the Pied-bills with full beaks trying to decide whether to eat a crayfish head first or tail first.  In contrast, the window for seeing Eared Grebes in Colorado in the spring is rather narrow (roughly late March through late May), so this was another lucky find.

Okay, maybe baby birds say spring better than warblers! This tired mama Great-horned Owl seemed unworried with our group; her owlets were far more curious. (c) David Chernack

We did pretty well with the raptors, even though we came away without having seen a Red-tailed Hawk.  However, a Northern Harrier, two Coopers Hawks, and, what was a first of the season bird for all of us, a Swainson’s Hawk made up for the Red-tail deficiency.

Additional highlights included a single Wilson’s Snipe, a beautiful male Audubon’s Warbler in full regalia, a small flock of migratory Lincoln’s Sparrows sticking to the lowlands for the time being, but heading up to breed in the montane willows eventually, and a large number of Tree Swallows coursing back and forth over the lake and grabbing insects from the water’s surface.  By the way, the Eared Grebe seemed to be taking advantage of this same food resource, whatever it was.

Finally, we wrapped up our morning with a Great Horned Owl mom sitting in her nest with two fuzzy nestlings.  All in all, another great morning bird-watching.

Pied-billed Grebes, while not the most bright and colorful of the waterfowl, are still a favorite of many birders. We counted more than a dozen as we circled Harriman Lake, most likely diving to catch crayfish on the bottom. (c) David Chernack

Hope to see you on another walk soon or at the FRBC open house on May 12 (we’re offering four different bird walks that morning)!

Chuck and David


Harriman Lake, Apr 7, 2018
42 species

Canada Goose (Branta canadensis)  7
Northern Shoveler (Spatula clypeata)  28
Gadwall (Mareca strepera)  9
Mallard (Anas platyrhynchos)  17
Ring-necked Duck (Aythya collaris)  3
Greater Scaup (Aythya marila)  3
Lesser Scaup (Aythya affinis)  23
Bufflehead (Bucephala albeola)  90
Common Goldeneye (Bucephala clangula)  15
Ruddy Duck (Oxyura jamaicensis)  45
Pied-billed Grebe (Podilymbus podiceps)  15
Eared Grebe (Podiceps nigricollis)  1
Double-crested Cormorant (Phalacrocorax auritus)  3
Great Blue Heron (Ardea herodias)  3
Northern Harrier (Circus hudsonius)  1
Cooper’s Hawk (Accipiter cooperii)  2
Swainson’s Hawk (Buteo swainsoni)  1
American Coot (Fulica americana)  155
Killdeer (Charadrius vociferus)  1
Wilson’s Snipe (Gallinago delicata)  1
Ring-billed Gull (Larus delawarensis)  2
Eurasian Collared-Dove (Streptopelia decaocto)  3
Mourning Dove (Zenaida macroura)  1
Great Horned Owl (Bubo virginianus)  3
Northern Flicker (Colaptes auratus)  5
Blue Jay (Cyanocitta cristata)  3
Black-billed Magpie (Pica hudsonia)  6
American Crow (Corvus brachyrhynchos)  8
Common Raven (Corvus corax)  2
Tree Swallow (Tachycineta bicolor)  45
Black-capped Chickadee (Poecile atricapillus)  3
White-breasted Nuthatch (Sitta carolinensis)  2
Brown Creeper (Certhia americana)  1
American Robin (Turdus migratorius)  12
European Starling (Sturnus vulgaris)  9
Yellow-rumped Warbler (Audubon’s) (Setophaga coronata auduboni)  1
Song Sparrow (Melospiza melodia)  6
Lincoln’s Sparrow (Melospiza lincolnii)  8
Western Meadowlark (Sturnella neglecta)  4
Red-winged Blackbird (Agelaius phoeniceus)  182
Common Grackle (Quiscalus quiscula)  11
House Finch (Haemorhous mexicanus)  3

Hudson Gardens, February 24, with Chuck Aid and David Chernack

The Snowman Stampede is a 5K, 10K, and half marathon race held every February in Littleton, and this year it was held on the day of our bird walk at Hudson Gardens. Fortunately, we were mostly able to do the necessary dodging when required, and were not significantly impacted by the hundreds of runners.

Our Mountain Bluebird was a big surprise for our group; they are very irregularly seen in suburban habitat so early in the year. (c) David Chernack

Here at the end of February we are on the cusp of so many interesting bird activities. First, and foremost it appears that the same pair of Red-tailed Hawks that were around last breeding season have returned to the area. These guys tend to hang out just across the river from Hudson Gardens, and are remarkable because while one is our standard light-morph western Red-tail, the other is an intermediate, or rufous-morph, western Red-tail. The variety of plumages that Red-tailed Hawks exhibit is truly incredible. Without going into too much detail, just know that there are 12 sub-species of Red-tails each tending to have either a dark or light morph, with some intermediate colored birds, and then you have the different plumages exhibited by juveniles versus adults. It can be quite the smorgasbord for us birders, as well as quite confusing!

Hooded Mergansers are a uniquely beautiful diving duck. The males we observed (like this individual) were a treat. (c) David Chernack

We are also commencing waterfowl spring migration which peaks towards the end of March (to be followed shortly thereafter in mid-April by the peak of shorebird migration). This is all by way of saying that we saw a good variety of geese and ducks (13 species). These guys are all in wonderful breeding plumage right now, and it’s a great show!

Bushtits are tiny cousins of chickadees that are constantly in motion, making them a challenge to photograph. (c) David Chernack

Other highlights included a few species that tend to be around throughout the winter, but one can never be guaranteed of seeing them: Killdeer, Bushtit, Brown Creeper, and Ruby-crowned Kinglet. This last is one of North America’s smallest songbirds wintering in a variety of habitats, and then here in Colorado breeding up in the Spruce-Fir Forest.

The aptly named Common Goldeneye is quite a looker with its bright white sides, dapper face coloration, and of course, its golden eye. (c) David Chernack

Finally, one other bird that can be here illusively in the winter is the Mountain Bluebird. We were fortunate to get several good looks at this outstanding fellow.

Thanks to those of you who braved the Snowman Stampede and the chilling winds that were with us almost all morning. And thanks to David Chernack for his excellent photos!

Good Birding!

Chuck and David

Hudson Gardens, Feb 24, 2018
35 species

Cackling Goose (Branta hutchinsii) 37
Canada Goose (Branta canadensis) 358
Northern Shoveler (Spatula clypeata) 31
Gadwall (Mareca strepera) 11
American Wigeon (Mareca americana) 7
Mallard (Anas platyrhynchos) 83
Green-winged Teal (Anas crecca) 6
Ring-necked Duck (Aythya collaris) 5
Lesser Scaup (Aythya affinis) 1
Bufflehead (Bucephala albeola) 16
Common Goldeneye (Bucephala clangula) 2
Hooded Merganser (Lophodytes cucullatus) 7
Common Merganser (Mergus merganser) 6
Pied-billed Grebe (Podilymbus podiceps) 2
Great Blue Heron (Ardea herodias) 1
Red-tailed Hawk (Buteo jamaicensis) 2
American Coot (Fulica americana) 3
Killdeer (Charadrius vociferus) 2
Ring-billed Gull (Larus delawarensis) 38
Herring Gull (Larus argentatus) 4
Eurasian Collared-Dove (Streptopelia decaocto) 1
Belted Kingfisher (Megaceryle alcyon) 1
Northern Flicker (Colaptes auratus) 4
Black-billed Magpie (Pica hudsonia) 6
American Crow (Corvus brachyrhynchos) 1
Black-capped Chickadee (Poecile atricapillus) 5
Bushtit (Psaltriparus minimus) 3
Red-breasted Nuthatch (Sitta canadensis) 1
White-breasted Nuthatch (Sitta carolinensis) 2
Brown Creeper (Certhia americana) 1
Ruby-crowned Kinglet (Regulus calendula) 1
Mountain Bluebird (Sialia currucoides) 1
European Starling (Sturnus vulgaris) 3
Red-winged Blackbird (Agelaius phoeniceus) 8
House Finch (Haemorhous mexicanus) 6

Hudson Gardens Bird Walk, January 27th, with David Chernack and Jennifer O’Keefe

Beautiful blue skies made for excellent birding this past Saturday morning along the South Platte River at Hudson Gardens. A wide range of birds were seen, from a tiny Ruby-crowned Kinglet to an enormous juvenile Bald Eagle and everything in between!

We often heard the duo of Belted Kingfishers approaching our group before we saw them — their metallic, rattling calls are unmistakable. (c) David Chernack

Our walk largely consisted of hugging the South Platte, keenly eyeing the only non-frozen water in the vicinity for large numbers of waterbirds. Present in huge numbers were Cackling geese, which actually vastly outnumbered their more well-known relatives, the Canada geese. Amongst the large number of Cackling and Canada geese was one “gray goose” from the genus Anser, which includes the Ross’s geese and Snow geese. Those species are uncommon but regular winter visitors to the greater Denver area, and associate with Cackling and Canada geese while here; in their breeding grounds, they also hybridize with them, creating a broad and confusing spectrum of hybrids which can be difficult to identify. Our mystery goose gave our group the impression of a Canada X Ross’s goose hybrid, but it flew off with several Cackling geese before we could make the final call. Shame!

Also present along the river were Denver’s usual cast of winter characters, including Ring-necked Ducks, Mallards, Green-winged Teals, Gadwalls, and Hooded Mergansers. Not seen on our previous excursion to Hudson Gardens, two female Common Mergansers were present along our route, with one individual which was preening gave us excellent scope views. A mated pair of Common Goldeneyes were also found amongst the other ducks, and showed off their bright breeding plumage. A handful of Buffleheads energetically foraged as we advanced along the river, diving below the surface and quickly resurfacing. 

Seeing a Ruby-crowned Kinglet on a crisp winter morning was a little boost of summertime for our group! This individual was photographed in Ken-Caryl in September. (c) David Chernack


Our group found a surprising diversity of landbirds along our route as well. A unique surprise was seeing a Ruby-crowned Kinglet, a tiny bird filled with energy. Interestingly, the bird was foraging alongside some sparrows and Brown Creepers. A distinctly not tiny bird which we spotted perched atop a telephone pole was an impressive immature Bald Eagle; the bird was just beginning to show off its distinctive white head plumage. Also seen were two cantankerous Belted Kingfishers, a pair of Northern Flickers, and a single Red-breasted Nuthatch.

Check out the full list of species below or on eBird here!

David Chernack

South Platte River and Reservoir, Jan. 6th, with Tom Bush and David Chernack

Despite some biting wind and cold on Saturday morning, fourteen brave birders embarked out to South Platte Reservoir to look for waterfowl and other winter birds on our first monthly bird walk of 2018. We racked up a grand total of 35 species in just under three hours in the field, including two rare birds for Colorado: a Horned Grebe and a Yellow-billed Loon.

The South Platte River offered a wonderful bird viewing opportunity as it concentrated more than a dozen species into a very small area of open water, including this Gadwall (L) and Northern Shoveler (R). (c) David Chernack

Our walk took place in two segments: first, we surveyed the large South Platte Reservoir for waterbirds — including the Yellow-billed Loon — and second, we followed the South Platte River towards the Chatfield dam and counted waterfowl and songbirds. Due to our surveying of two distinct types of habitat on our trip, the waterbird biodiversity we observed was notably high: nineteen of the species we saw were waterbirds or waterfowl of some sort. These ranged from a large Canvasback on the reservoir to a raft of tiny Buffleheads along the river to a small group of dazzling Wood Ducks below the Chatfield dam. 

The most numerous species spotted along our route were, as usual, Canada Geese — along with their close relatives, Cackling Geese. Though visibly very similar, the two species can be told apart by their calls and size, with the Cackling Goose being far more compact than its Canadian cousin. Also in abundance were Mallards and Buffleheads, with 44  and 41 individuals of each species seen respectively. Mallards and Buffleheads displayed the two principal duck feeding behaviors: dabbling and diving. While the Mallards skimmed the water’s surface and dipped their fronts underwater for aquatic plants, the Buffleheads dove towards the river bottom to forage for small aquatic crustaceans and other prey items. 

Cackling geese lived up to their name on our walk, as their cacophonous calls rivaled the road noise from nearby C-470. (c) David Chernack

One of the Buffleheads’ cousins in the genus Bucephala, the Common Goldeneye, was another delight to see along our route. The Goldeneyes, like many of the other ducks observed foraging along the river, are only in Colorado as winter visitors — they breed across Canada on wooded lakeshores — but set themselves apart as cavity nesters; Wood Ducks and Hooded Mergansers were some other ducks we spotted which will nest in natural cavities or abandoned woodpecker nests come springtime. Four members from genus Aythya, which includes several species of diving duck worldwide, were on display as well: the Lesser Scaup, Ring-necked Duck, Redhead, and Canvasback were all visible. Many of the males showed off their bright breeding plumage, ready to perform elaborate courtship displays to impress females of their species. However, both of the grebe species we saw — the Pied-billed and Horned grebes — donned their drab non-breeding plumage.

While not as dazzling as the goldeneyes or mergansers, Pied-billed Grebes are a Colorado winter birding staple we were happy to observe foraging alongside other ducks and geese. (c) David Chernack

While all of our waterfowl sightings were exciting, the most anticipated highlight of the morning was a rarity to Colorado: a Yellow-billed Loon (Gavia adamsii). The loon was observed on the far northern side of the South Platte Reservoir, diving intermittently to forage. This magnificent species has only been observed in Colorado a handful of times; it can be more reliably observed on the Arctic coast where it breeds during spring and summer.

This female Belted Kingfisher had words with us when we stumbled upon her feeding grounds! (c) David Chernack

Yellow-billed Loons are poorly understood birds: while five distinct breeding groups are recognized in Canada, Alaska, and Siberia, their diet and the exact size of their global population are not concretely known. (Estimates place it at around 10,000 individuals, with around 4,000 of those breeding in northern Alaska.) The species is rated by the International Union for the Conservation of Nature (IUCN) as Near Threatened, and “it is suspected to be undergoing a moderately rapid population decline owing to unsustainable subsistence harvest and almost qualifies for listing as threatened” according to the IUCN’s “Red List”; the potential expansion of Arctic drilling on their breeding grounds, oil spills, and climate change are considered to be other threats to the loon. Needless to say, our group was extremely lucky to observe such a mysterious bird visitor so far inland. For more information about the Yellow-billed Loon and its conservation, visit the National Audubon Society’s online field guide entry about this fantastic species. 

While not an impressive capture at a third of a mile away, this Yellow-billed loon was still the darling of many a birder as we surveyed the reservoir.

Though the waterfowl both rare and common stole the show, we also observed a good number of songbirds, raptors, and other birds along our way. Four Red-tailed hawks, an American kestrel, and a passing adult Bald Eagle rounded out our raptor tallies, while songbirds including song sparrows, brown creepers, and a single American tree sparrow were also a treat to see. 

Check out even more photos of this morning’s birds as well as our full species list in the gallery below!

Your humble scribe and photographer,

David Chernack


South Platte Reservoir and Vicinity, Jan 6, 2018

35 Species

23 Cackling Goose
98 Canada Goose
5 Wood Duck
21 Northern Shoveler
5 Gadwall
44 Mallard
1 Green-winged Teal
1 Canvasback
12 Redhead
6 Ring-necked Duck
26 Lesser Scaup
41 Bufflehead
17 Common Goldeneye
6 Hooded Merganser
14 Ruddy Duck
1 Yellow-billed Loon
1 Horned Grebe
2 Pied-billed Grebe
1 Bald Eagle
4 Red-tailed Hawk
36 American Coot
4 Ring-billed Gull
2 Eurasian Collared Dove
2 Belted Kingfisher 
1 Northern Flicker
1 American Kestrel
2 Black-billed Magpie
12 American Crow
1 Common Raven
5 Black-capped Chickadee
1 White-breasted Nuthatch
2 Brown Creeper
1 American Tree Sparrow
3 Song Sparrow
2 House Finch

Denver Botanic Gardens at Chatfield, Dec 2, with Chuck Aid and David Chernack

Snow Goose (c) Bill Schmoker

The weather was surprisingly mild for early December, and though we started out with our coats on it was not long before several of us were down to shirtsleeves.  November can be a good time to start seeing a wide variety of wintering geese and ducks, and while we had good luck getting three species of geese, Snow, Cackling, and Canada, we only came away with three species of ducks which is below what one might expect this time of year.  The high number of Mallards, almost 300, was most impressive.

Canada and Cackling Geese (c) Bill Schmoker

We managed to do well with the raptors.  We saw four Red-tails, and even though they were all our usual light plumaged western morph, there was good variety in their appearance.  There was a juvenile with a banded tail, and an adult with a “red” tail; some had more white on the scapulars, and others had less; some had a more obvious belly-band, others less so; and so it went.  One thing to start looking for in your Red-tails is whether they have a dark chin and throat (our western birds), or whether they have a white chin and throat (Eastern birds).  Living where we do at the foot of the Rockies – where East meets West – we are in a region where we find eastern and western forms of many species. 

Red-tailed Hawk – eastern juvenile (c) Bill Schmoker
Red-tailed Hawk -western adult (c) Bill Schmoker

As for our other raptors we had a distant, silhouetted view of a Prairie Falcon perched high on a pole – a bit more slender than a Buteo (the genus of soaring hawks), with a longer tail, and overall rather pale looking.  We had a great look at a Northern Harrier cruising low over the fields and wetlands – a slender bird with a long, banded tail, and long wings raised in a dihedral; and the white rump is always obvious.  And then we had another falcon, an American Kestrel, with beautiful rufous barring on her back.

A few other highlights were provided by a good number of American Tree Sparrows, and then we had three races of Dark-eyed Juncos: Slate-colored, Oregon, and Pink-sided.  There are six races that occur around here in the winter, and it can be fun (and challenging) to sort them out.  At one time, they were considered to all be distinct species, but for now they have been lumped together as Dark-eyed Juncos.

We hope to see you on another walk soon!

Chuck and David


Denver Botanic Gardens at Chatfield, Dec 2, 2017
28 species

Snow Goose (Anser caerulescens)  1
Cackling Goose (Branta hutchinsii)  12
Canada Goose (Branta canadensis)  1500
Gadwall (Mareca strepera)  2
American Wigeon (Mareca americana)  3
Mallard (Anas platyrhynchos)  290
Great Blue Heron (Ardea herodias)  3
Northern Harrier (Circus hudsonius)  1
Red-tailed Hawk (Buteo jamaicensis)  4
Rock Pigeon (Feral Pigeon) (Columba livia (Feral Pigeon))  72
Eurasian Collared-Dove (Streptopelia decaocto)  10
Downy Woodpecker (Picoides pubescens)  4
Northern Flicker (Colaptes auratus)  4
American Kestrel (Falco sparverius)  1
Prairie Falcon (Falco mexicanus)  1
Black-billed Magpie (Pica hudsonia)  13
American Crow (Corvus brachyrhynchos)  112
Black-capped Chickadee (Poecile atricapillus)  6
White-breasted Nuthatch (Sitta carolinensis)  3
Brown Creeper (Certhia americana)  1
Townsend’s Solitaire (Myadestes townsendi)  1
American Robin (Turdus migratorius)  4
American Tree Sparrow (Spizelloides arborea)  14
Dark-eyed Junco (Junco hyemalis)  4
Dark-eyed Junco (Slate-colored) (Junco hyemalis hyemalis/carolinensis)  5
Dark-eyed Junco (Oregon) (Junco hyemalis [oreganus Group])  7
Dark-eyed Junco (Pink-sided) (Junco hyemalis mearnsi)  1
Song Sparrow (Melospiza melodia)  1
Red-winged Blackbird (Agelaius phoeniceus)  193
House Finch (Haemorhous mexicanus)  71
American Goldfinch (Spinus tristis)  5

Hudson Gardens Bird Walk, November 18 with Tom Bush and David Chernack

It was a chilly one out on Saturday morning, but the birds were out and a pleasant time was had birding at Hudson Gardens! We observed a respectable total of 24 species (see the full list below or on eBird here), including some great wintering waterfowl and a wonderful winter surprise: a Northern Shrike. 

Cackling geese inundated the lawns of the Gardens this morning. Note their stubbier neck relative to their more well-known cousin, the Canada goose.
American wigeons are unique ducks: they are parasitic — often choosing to steal prey from other waterfowl rather than finding their own — and their calls sound like a windup toy.

Eight of the species observed — largely on the South Platte River or on small ponds nearby — were a mixture of geese, ducks, and other waterfowl. The most numerous birds observed were Canada Geese and their close cousins, Cackling Geese; both are members of the genus Branta. Though visibly very similar, the two species can be told apart by their calls (the cackling goose makes a slightly higher “honk” than the Canada goose) and by the length of their necks, with the cackling goose having a more compact neck than its Canadian relative.

Also in abundance were Mallards, with precisely 69 seen over the course of the trip; Mallards are included in the genus Anas, which encompasses some 31 species of dabbling ducks worldwide. Another member of the genus observed on the South Platte this morning were a duo of male Green-winged Teals. Several Gadwalls and American Wigeons — common winter dabbling ducks — were also observed foraging alongside the Mallards and teals. 

One of our diving ducks, the Bufflehead, was also out on the river, with both darker immature individuals and females and bright white mature males on display. No sign of the Buffleheads’ relatives in the genus Bucephala, the Common and Barrow’s Goldeneyes, on this trip however. Also putting some bright white breeding plumage on display were Hooded Mergansers, who were diving to forage alongside a large group of Gadwalls. Though these wonderful waterfowl species were a delight to see, notably missing were any species from genus Aythya: the Greater and Lesser Scaups, Ring-necked Duck, Redhead, and Canvasback. 

One great surprise we had this morning was a bird with a high fearsomeness-to-size ratio: a Northern Shrike! Shrikes are technically songbirds; however, they hunt for prey such as lizards and small rodents just like raptors. Since they are not technically raptors and don’t have large talons at their disposal, shrikes will attack and carry prey with their specially adapted hooked bills; in order to kill and consume their prey, they will impale their unfortunate catch on spikes, such as the thorns on a honeylocust tree on the barbs of a barbed wire. As their name suggests, these shrikes breed spruce forests in Alaska and the northern Canadian provinces; they spend their winters from British Columbia to Massachusetts. Getting to see one on our walk was a real treat. 

Our surprise shrike was too far away to get much of a snapshot, but you can still see this individual (likely a first-year bird) has a distinct hooked beak. This one was showing a diagnostic shrike behavior: perching high in a tree to survey the ground below for prey.

Aside from waterbirds and the shrike, the normal cast of characters was present during our walk: Northern flickers, a Killdeer, American Robins, Red-tailed hawks, Ring-billed Gulls, and a single female American kestrel were all spotted.

Finally, we had good numbers of feeder birds close to the end of our trip, including Downy Woodpeckers, Red-breasted Nuthatches, House Finches, American goldfinches, Dark-eyed Juncos, and plenty of Black-capped Chickadees. 

This trip was emblematic of the joys of Colorado winter birding: even in a location with a relatively high level of habitat disturbance and modification by humans, a wonderful suite of birds was present and could be seen fairly easily. As a recent transplant to Colorado from New England, I’m constantly impressed with the ease and facility with which one can observe many wonderful wild species, even in Denver’s back doorstep. All the more reason to get out those binoculars and check out our native avian fauna this winter! Check out even more photos of this morning’s birds in the gallery below.

Your humble scribe and photographer,

David Chernack





Hudson Gardens, November 18

24 species

53 Cackling Goose
200 Canada Goose 
20 Gadwall 
18 American Wigeon 
69 Mallard 
2 Green-winged Teal — Both males 
10 Bufflehead 
5 Hooded Merganser 
2 Red-tailed Hawk 
1 Killdeer 
6 Ring-billed Gull 
1 Belted Kingfisher 
3 Downy Woodpecker 
1 American Kestrel — Female
1 Northern Shrike — Female 
5 Black-billed Magpie 
5 American Crow 
12 Black-capped Chickadee 
2 Red-breasted Nuthatch 
1 American Robin 
5 Dark-eyed Junco (Slate-colored) 
12 House Finch 
10 American Goldfinch 
2 House Sparrow