The weather was cold and wet this morning but the upbeat attitudes and great conversation made this walk very pleasant and fun. We started off the day with some American goldfinches feasting on wild sunflowers, and even though they were flitting about we still managed to get everyone some good views of the male with his bright yellow feathers starting to fade into his more drab winter plumage. In fact, we get asked all the time in the store if goldfinches migrate, but the truth is, goldfinches are found in Boulder County year round- only in winter they are in disguise!
American Goldfinch in drab winter plumage. Photo by Jamie Simo.
As we continued down the hill towards the bridge, lots of wet birds were seen through the scope- northern flickers, American kestrels, mourning doves, and even a pair of adult bald eagles with their highly vocal juvenile offspring. We were also treated to a flock of blue-winged teal, a belted kingfisher, and a solitary sandpiper, all viewed from the first bridge. Further along we had a great blue heron, cliff and barn swallows, and a double crested cormorant. We finished off the day with a Cooper’s hawk at a distance- this provided us with a great opportunity to practice raptor identification.
Solitary Sandpiper. Photo by Aron Smolley.
Although on this walk we didn’t see that many species, a good time was still had by all. At the very least it was a great demonstration of the high performance of the Zeiss Gavia spotting scope even on a rainy day, still providing us crisp detail and bright colors despite the low light due to the sky being overcast. Come visit our Boulder location to try out the Gavia for yourselves!
We couldn’t have had a better day this past Saturday for our trip to Stearn’s Lake! Stearn’s Lake is located within the Carolyn Holmberg Preserve at Rock Creek Farm, which is managed by Boulder County Parks and Open Space. The big draw at Stearn’s Lake is the presence of nesting Bald Eagles and we weren’t disappointed; both parents were in attendance and several of us were lucky enough to see a chick poking its head up occasionally. One walk participant aptly compared the chick’s behavior to whack-a-mole!
Bald Eagles lay between 1 and 3 eggs and generally nest in big, sturdy trees near water. While their main diet is usually fish, here in Colorado a major source of food is prairie dogs, so this nest is ideally situated with a prairie dog colony right next door. Because CPW recommends a buffer zone of 1/2 a mile away from Bald Eagle nests, we tried to keep moving along the trail where it fell within that buffer zone.
Breeding and nesting season is my favorite time of year and we had not only nesting Bald Eagles on our walk, but also a nesting Red-tailed Hawk and a Great Horned Owl with three branching owlets. It was really interesting to see the different nesting stages between the birds. Great Horned Owls tend to be one of the earliest nesters, often on eggs by Valentine’s Day with the chicks hatching out about 30 days after eggs are laid. The owlets will stay in the parents’ territory until October-ish when the parents begin courting again.
Hovering male Belted Kingfisher. Photo by Jamie Simo.
Bald Eagles typically begin laying eggs a little later than Great Horned Owls in March, while Red-tailed Hawks lay their eggs even later, usually in late March or April. A good rule of thumb is generally that the bigger the bird, the longer incubation and fledging takes so it’s advantageous, especially for predators, to nest earlier in the season so the chicks are ready to take advantage of the bounty of prey later in the season.
While the lake was too high for any shorebirds, we did get to see some water birds, including Lesser Scaup, Northern Shovelers, both Western and Pied-billed Grebes, Double-crested Cormorants, an American Coot, and one female Common Merganser. We also got to see a Belted Kingfisher hovering and diving for fish.
Vesper Sparrow. Photo by Jamie Simo
Probably the highlight of the walk was the first of season Vesper Sparrow we saw in the grass along the trail. Stearn’s Lake is a perfect place to see a Vesper Sparrow, which are grassland habitat specialists that construct their nests on the ground under other vegetation. This one didn’t have as prominent of a white eye ring as most Vesper Sparrows, but the rusty patch on the “shoulder” of the wing was a dead giveaway.
In total we had 26 species, including a first of season Cliff Swallow, not too shabby!
Stearns Lake, Boulder, Colorado, US 26 species
Canada Goose 2 Northern Shoveler 4 Lesser Scaup 2 Common Merganser 1 Pied-billed Grebe 1 Western Grebe 1 Rock Pigeon (Feral Pigeon) 3 Eurasian Collared-Dove 1 Mourning Dove 1 American Coot 1 Killdeer 1 Double-crested Cormorant 3 Great Blue Heron 1 Bald Eagle 2 Red-tailed Hawk 2 Great Horned Owl 4 3 owlets Belted Kingfisher 1 Black-billed Magpie 4 Cliff Swallow 1 Small swallow, “headlight,” rusty and cream colors no forked tail European Starling 7 American Robin 2 Vesper Sparrow 1 Small sparrow, rusty patch on shoulder, streaked breast, white eyering Song Sparrow 1 Western Meadowlark 8 Red-winged Blackbird 20 Common Grackle 5
In March, one can almost sense the excitement of Colorado birders in the air: the changing of the guard is near! Soon, after a long winter of anticipation, the spring migrants and summer breeders will be arriving in our favorite patches, and our winter visitors will be heading off to points north. But until then, we can still enjoy the winter waterfowl in their breeding finery, at the same time that we are enjoying the early-spring songs of our local year-round resident birds gearing up for the breeding season.
Adult Cooper’s Hawk. Photo by Sarah Spotten.
Waneka Lake and adjacent Greenlee Preserve in Lafayette, Colorado boast several habitats which attract a diverse mix of birds year-round: reservoir, wetland, and nearby farmland surrounded by suburban neighborhoods. At Greenlee Preserve there are also some bird feeders, which have been known to host wintering White-throated Sparrows and several species of hummingbirds in the summer.
Our outing on March 9, 2024 began with the raucous serenade of dozens of European Starlings singing in the trees near the Waneka Lake Park parking lot, imitating several other birds like American Kestrel, Killdeer, and what sounded like Sora. Northern Flickers were also giving their territorial calls and drumming on trees and trash cans. Not far from the parking lot, we found an adult Cooper’s Hawk, which betrayed its presence by its “kek-kek-kek” call. This adult perched in one spot long enough for us all to get great looks through the scope. At one point, it was joined by a second individual, this one an immature bird, allowing us to compare how the plumages of the two ages differ.
Waterfowl was scarce on Waneka Lake, but we did have a few species on the water: Canada Goose, Common and Hooded Mergansers, Gadwall, Mallard, and Green-winged Teal. Greenlee Preserve, surprisingly, was a bit of a bust – hardly any birds around! But, that’s the nature of nature sometimes. We did have a couple of singing Red-winged Blackbirds nearby and two Black-capped Chickadees checking out potential nest cavities in tree branches.
White Pelicans. Photo by Sarah Spotten.
Most of the group continued walking on to nearby Hecla Lake, about a half-mile southwest of Waneka Lake Park. On the way there, we heard and saw a singing White-breasted Nuthatch, singing Black-capped Chickadees, and singing House Finches. Although the water level was low at Hecla Lake, there were a number of interesting birds about. We got good scope views of Green-winged Teal, Ring-necked Duck, and Northern Shoveler. A group of Cackling Geese, conveniently hanging out with some Canada Geese, afforded some good comparison between these very similar-looking species. It still somehow seems like recent news, but I realized in writing this report that it will be 20 years this year since Cackling Goose was split off as a separate species from Canada Goose by the American Ornithological Society (Banks, et al. 2004). One of the best finds for the day at Hecla Lake was two American White Pelicans, which as of this writing appears to be the first eBird report of American White Pelicans for the season in Boulder County! Spring is indeed on its way.
Cackling Geese. Photo by Sarah Spotten.
Thanks to everyone who joined us this morning for some good birding and good company. See you next time – until then, happy spring migration!
Banks, Richard C., Carla Cicero, Jon L. Dunn, Andrew W. Kratter, Pamela C. Rasmussen, J. V. Remsen, James D. Rising, and Douglas F. Stotz. Forty-Fifth Supplement to the American Ornithologists’ Union Check-List of North American Birds. The Auk, Volume 121, Issue 3, 1 July 2004, Pages 985–995, https://doi.org/10.1093/auk/121.3.985
Well, it was certainly a cold, snowy morning for a bird walk, but after having to cancel due to dangerous cold last month, I was reluctant to cancel a second month in a row. Happily, the weather meant we had the trail to ourselves and the ducks! One of the best things about Milavec Reservoir is how small it is and how the trail goes all the way around so it’s very easy to get good looks at everything on the water.
Northern Shoveler pair. Photo by Jamie Simo.
Strangely, there weren’t any geese on the water on Saturday, though we more than made up for it by the number of ducks, especially Northern Shovelers, which were by far the most numerous species. The sound of their wings was impressive when a young Bald Eagle flew over, flushing them briefly. Intermingled were a good number of Canvasbacks, which are named for the male’s bright white body that resembles the color of a blank canvas. They are the largest of our diving ducks and have a distinctive, “ski slope” forehead. Other ducks present were Common Goldeneye, Mallards, and even a pair of Green-winged Teal.
One of the other most numerous species was the Common Merganser. Mergansers’ bills are narrower and sharper than most other ducks with serrations that make it easy for them to grab and eat fish and mollusks. In fact, those serrations earn them the nickname “sawbill” in some circles.
While there weren’t many songbirds that braved the weather, we did see and hear several Horned Larks fly over. Horned Larks have distinctive “horns” (really feathers) on their heads called plumicorns, and dark facial masks. Their presence was likely due to the fallow agriculture field next to the reservoir as they love bare ground and short grasses. Believe it or not, Horned Larks are the only true lark found in North America; Meadowlarks are actually members of the blackbird family.
Horned Lark. Photo by Jamie Simo.
A short but sweet walk, we netted 16 species in all, which wasn’t too shabby all things considered. Here’s to a warmer, sunnier March bird walk!
Frederick Lake (Milavec Reservoir) & Recreation Area, Weld, Colorado, US 16 species (+1 other taxa)
Canada Goose 1 Cackling/Canada Goose 7 Northern Shoveler 400 Mallard 27 Green-winged Teal 2 Canvasback 10 Common Goldeneye 10 Common Merganser 20 Ring-billed Gull 2 Bald Eagle 1 Northern Flicker 2 Black-billed Magpie 1 American Crow 1 Horned Lark 4 American Robin 3 American Goldfinch 1 Song Sparrow 2
The South Platte in Adams County near 88th Avenue was the destination for the Littleton store’s walk on January 6. The river is a winter haven for many hundreds of ducks, its food resources bolstered by the inflow from a water treatment plant located upstream. The nutrient rich – and warmer – waters attract many ducks during the winter season as they gather to feed and find refuge.
We walked to different vantage points along the river, at first braving a chill breeze, but later ready to shed some of our winter layers. Ducks crowded the river all the way. We saw many Northern Shovelers, Gadwall, Green-winged Teal, Northern Pintail, and Mallards, representing our dabbling ducks. Diving ducks were less numerous in the river channel than the dabblers, but we saw many Bufflehead and Common Goldeneye, and one section had lots of goldeneyes and Lesser Scaup. As we walked along we spied hunting a Northern Harrier and a cooperative American Kestrel.
The Platte’s channel is shallow, but large reservoirs lying alongside the river corridor offer a deeper water habitat, probably with more fish, too. These attract mostly diving ducks during winter. We climbed up a low bank to scan the birds at one of the reservoirs. There we added all three merganser species – Common, Hooded and Red-breasted, and many more scaup.
Birding the South Platte River Trail north of Denver is like finding a ribbon of life tucked away in an urban world. During our visit, all the waterfowl along the river seemed to be at peace. Plenty of food and resting places for all, and the winter sun highlighting such wonderful and varied colors and patterns on the ducks. It makes a fine winter walk.
I wasn’t sure what the weather would be like the morning of the bird walk given the winter storm warning we had the previous day, but Saturday dawned cold, but bright and sunny. It was a perfect winter wonderland day with fresh snow!
White Rocks Trail in the winter is a fantastic place to view raptors and right off the bat we had our first: a female American Kestrel perched right over the trail. American Kestrels are our smallest falcon being about the size of a Blue Jay or Mourning Dove, and one of the only raptors in Colorado where the plumage of males and females are noticeably different. Females are mostly brown with dark barring on the back while males are rusty and slate-blue. Look for them on power lines where their distinctive, hunched posture and tail pumping easily give them away. You can also sometimes see them mobbing larger raptors like Red-tailed Hawks in defiance of their small size!
Female American Kestrel. Photo by Jamie Simo
Bald Eagles have been known to inhabit the area around White Rocks and sound was our first indication that the pair was in residence that morning. Contrary to what advertisers would have you believe, Bald Eagles don’t “scream” like Red-tailed Hawks, but emit a series of high-pitched whistles. Sure enough, we were soon able to get a good view of the pair perched in trees ringing the mostly frozen pond #9 on the adjacent ERTL property.
We also had an id challenge farther along the trail when we saw a large Buteo (soaring hawk) perched in a tree. Our initial thought was that the bird was a Red-tailed Hawk, which is the most common soaring hawk in Colorado. However, certain things didn’t quite add up. For one, even though the bird did have brown speckling across its white breast like the “belly band” of a Red-tailed Hawk, the head that was more pale than a Red-tail’s chocolate brown was odd. The biggest indicator though was the large, yellow mouth “gape,” which is a characteristic of the Ferruginous Hawk. After consulting photos, we determined we were indeed looking at a juvenile Ferruginous Hawk! Ferruginous Hawks are closely tied to prairie dog towns, which is their main source of food, and White Rocks Trail has no shortage of prairie dogs.
Juvenile Ferruginous Hawk. Photo by Jamie Simo
Other target species which we were fortunate enough to see were the Northern Shrike (an arctic breeder and resident in the northern portion of the US only in the winter) and several immature Northern Harriers, which passed by close enough for stunning views of their pumpkin-colored bellies.
Finally, not a bird, but we were also treated to a hunting coyote. Unconcerned by his/her audience, the coyote repeatedly pounced in the grasses off to the side of the trail. Finally, success! We watched as it contentedly munched on an unlucky vole. You never know what you’ll see when you come out on a bird walk with us!
Coyote eating a (meadow?) vole. Photo by Jamie Simo
White Rocks Trail area, Boulder, Colorado, US 28 species (+1 other taxa)
Cackling Goose 21 Canada Goose 15 Cackling/Canada Goose 27 Gadwall 7 American Wigeon 4 Mallard 6 Common Merganser 2 American Coot 1 Ring-billed Gull 7 Northern Harrier 2 Bald Eagle 2 Red-tailed Hawk 3 Ferruginous Hawk 1 Northern Flicker 1 American Kestrel 1 Northern Shrike 1 Blue Jay 3 Black-billed Magpie 1 Common Raven 1 European Starling 83 American Goldfinch 3 White-crowned Sparrow (Gambel’s) 40 Song Sparrow 5 Spotted Towhee 1 Rock Pigeon (Feral Pigeon) 20 Belted Kingfisher 1 Say’s Phoebe 1 Western Meadowlark 19 Red-winged Blackbird 6
Today we were reminded we were in Colorado in December. Yes, we had some sunshine and pretty blue skies, but also a biting chill wind picked up as we began; our cheeks, fingers, and toes suffered. Wind makes land birding pretty tough, but our waterbirds may still be enjoyed. It was not so windy yet as we began at Prospect Lake, where hundreds of geese were the dominant theme. They were mostly Cackling Geese (short stature, near vertical forehead, short triangle bill, high barking calls) with great comparisons to the much larger but less numerous Canada Geese (sloped forehead, long bill, much bigger than Mallards). Prospect Lake also had a pair of Wood Ducks, some Lesser Scaup and a few others. The winds grew and we dropped down to follow the trail up Clear Creek where there was a bit of shelter. Green-winged Teal added some flair among handsome Mallards and Gadwalls that love the creek, and an American Dipper buzzed in to offer great views! Up at exposed and windy Tabor Lake we found many ducks had sheltered along the west side, including a wonderful assembly of over 120 Hooded Mergansers. Red-breasted Mergansers were also there, along with Pied-billed Grebe, Great Blue Heron, and lots of Shovelers. The heron flew in and flushed the crowd of shovelers from their sheltered shore. The flock flew fast over us, while flocks of Cacklers passed over higher up in other directions, blown to the side in the wind. It was a magical late fall moment. December birding brings cold and sometimes wind, but there is great beauty, too. And always some treat awaits us birders who venture out to take a look.
We began with a loud call of American Crow, in the stand of pines trees we observed flocks of Bustits, it’s a social songbird & one of the smallest passerines in North America. They were feeding on small insects & Bustits do love spiders one of their favorites. Along the South Platte, we heard many calls of American Goldfinches, Song Sparrows, House Finches singing, & Black-capped Chickadees surrounded us with their bouncy flight in & near cattails. As we continued along the river, Mourning Dove flew above with its long, pointed tail, & a sizable Buck was startled running along the other side river. Just as we headed across the bridge, we noticed a few Killdeers on the rocks in water & several Mallards, Buffleheads, & one stunning Common male Goldeneye. Passing the bridge, off to left a trail led us to a peaceful pond filled with Ducks both (dabblers & divers). We saw few Buffleheads, American Widgeons, a pair of Northern Shovelers, several Ring-necked Ducks, one Lesser Scaup, one American Coot. At the pond we watched closely 3 muskrats eating pond weeds or it looked like Cattails roots, & two Beavers swam by us. As we were getting ready to return back a few Common Mergansers flew in. These Mergansers, our only ducks that specific in eating fish & the largest of the three Mergansers we have. A delightful sunny bird trip with lots of Nature that surrounded us.
Ancestral home of the Arapahoe, the Ron Stewart Preserve at Rabbit Mountain is roughly 5,000 acres of grassland and foothills habitat. It boasts some of the most spectacular views of the Front Range and is home to a multitude of species.
Our walk on Saturday was rather quiet, but we did see a few good birds and the landscape and weather were beautiful. Despite mostly occurring in the western and southwestern portion of Colorado, a small population of Pinyon Jays can be found at Rabbit Mountain. Though the Pinyons were elusive for us, we did see a couple of their relative the Woodhouse’s Scrub-Jay right in the parking lot. Woodhouses’s Scrub-Jays differ from Pinyon Jays in having longer tails and grey as well as blue on their bodies. Pinyon Jays also have longer, sharper bills than the Scrub-Jays.
Woodhouse’s Scrub-Jay. Photo by Jamie Simo
A little farther down the trail we saw another great bird, a Prairie Falcon. Rabbit Mountain is an ideal habitat for Prairie Falcons, which nest on rocky cliff faces and feed on small mammals and grassland birds like meadowlarks. Unlike Peregrine Falcons, Prairie Falcons are brown and white rather than mostly grey with less of a helmeted look than their more famous relative. As they soar above you, look for their distinctive dark axillaries or “armpits.”
Prairie Falcon. Photo by Jamie Simo
We also saw a Ferruginous Hawk surveying the prairie dog town. This large hawk’s diet is mostly made up of prairie dogs and they can often be found on the ground in the middle of one of the rodent’s colonies, which is precisely where we found it.
Finally, we had a Clark’s Nutcracker in the pines at the beginning of the Eagle Wind Trail. These cool corvids cache thousands of pine seeds a year and is considered a keystone species for its role in the spread of whitebark pine.
Rabbit Mountain, Boulder, Colorado, US 13 species (+1 other taxa)
The quiet little town of Louviers sits off the busy corridor of Highway 85 in Douglas County, marked from afar by an impressive stand of tall pines and other trees, on a hillside along the autumn gold cottonwoods of Plum Creek. The town came to be in 1906 as a company town to support the new DuPont Dynamite Works built adjacent to the town. Now the dynamite plant is gone and the former company town is an historic point of interest that offers a lovely stroll and fun birding, too. DuPont Park Open Space neighbors the town and has trails through the riparian forest and through the grounds of the former dynamite plant, now “returning to nature.”
Our Front Range Birding Company walk enjoyed October’s mix of migrants and resident birds. Hot spots of bird action stopped us here and there as we made our way through the town. Right away our attention was captured by a party of migrant Western Bluebirds that had stopped in to forage. Flocks of migrant White-crowned Sparrows were occupying thickets and gardens, filling the air with a chorus of song and calls. White-crowned Sparrows differ from many of our fall migrants in that they love to sing when they pass through our area. Both adult and juvenile sparrows sing, tossing out lovely trills and song phrases. This is a time when young birds learn and practice their songs.
As we watched one sparrow flock we spotted a chunky, streaky bird with a large bill feeding by itself on a gravel alleyway. Surprise: a juvenile Red Crossbill! Not red at all but streaky and drab. But photos reveal areas of yellow-gold feathers molting in, showing it to be a young female crossbill. And what a bill! It was odd to see just one crossbill by itself. I had seen a lot of crossbills in town in prior weeks, so perhaps this lonely bird was left behind! Later we heard it call as it flew and could identify it as the Type 4 Red Crossbill – the Douglas-fir Red Crossbill — a form that is infrequently found in Colorado.
Our walk continued with many lovely views of fall color, chances to compare resident birds like Downy and Hairy Woodpeckers, and to enjoy our quiet walk through the big trees of DuPont Park. It is good to be out birding in the fall.
The Denver region is a “ducky” place as fall deepens into winter and waterfowl come south to make their home in our rivers and lakes. The South Platte corridor and nearby reservoirs and lakes are a key area for migrant ducks. We can see a great variety of ducks in winter, when 20 different species are present in the area, and some places have good numbers, too.
South Platte Park is a “ducky” park in Littleton. Our visit on November 4 enjoyed partly cloudy skies and mild temperatures – a beautiful fall day. There are large lakes, a reservoir, and the river. Here is our South Platte Park trip report. We were happy to see 10 different species, including a rather uncommon Long-tailed Duck at Eaglewatch Lake. Our ten species were evenly split between ducks that forage at the surface and those that dive under the water.
The grouping of “dabbling ducks” vs. “diving ducks” is a familiar one, and it reflects an important basic difference among our ducks, both in their natural history and the taxonomic relationships among species. Our dabblers on the field trip were Northern Shoveler, Gadwall, American Wigeon, Mallard and Green-winged Teal. Our divers were Lesser Scaup, Long-tailed Duck, Bufflehead, Hooded Merganser and Ruddy Duck.
We see dabblers “tipping up” to reach down into the water after food, or feeding at the surface, or along a shallow muddy margin, and sometimes up on grassy areas and in fields. We see divers diving under the water — propelled by feet and wings — to find fish, shellfish and other invertebrates in the water column and at the bottom.
Dabblers often use their bills to sift water, mud and aquatic vegetation to extract small bits of food, and they even eat vegetation. Divers catch prey in their bill, whether sessile or mobile, and bring it to the surface to prepare it for swallowing. Crayfish, which are abundant in our waters, are a popular food for some of our divers.
Dabbers are often seen walking on land, and they can take flight directly upward into the air. Divers have legs set farther back. They are seldom seen on land and cannot walk well. Most Divers must run and patter over the water to take flight.
Dabblers and divers are incredibly beautiful, bringing us joy as we identify and watch them here in the winter. Look for other opportunities to enjoy our winter ducks on upcoming Front Range Birding Co. trips. Learn more about ID of our winter ducks with David’s video BIRD BOMBS: Better Duck.
