Tag: Bird Walk

Saturday, May 10, 2025 Bird Walk to Meyer’s Gulch at Walker Ranch with Jamie Simo and Gabbie Lochbaum

Posted on May 11, 2025 by frbcadmin - Bird Walks, Blog

This past Saturday was a gorgeous day for a bird walk up at Walker Ranch. Settled in 1865 by James A. Walker, Walker Ranch is on the National Register of Historic Places not just for its historic buildings dating back to that time period, but also for several archeological sites from indigenous peoples, including the Arapahoe.

Before we even got very far on the trail we were greeted by the first of many singing Vesper Sparrows. Male Vesper Sparrows are easy to see during breeding season because they will sit on an exposed perch in the grassland and sing continuously. Their name comes from the fact that they will sing into the twilight hours, vesper meaning “evening” in Latin. They can be distinguished by their white eye ring, streaky breast, white outer tail feathers, and pale “mustache.”

Female Western Bluebird with nesting material. Photo by Jamie Simo.

Further into the scattered Ponderosas we encountered several Western Bluebirds and we were lucky to see a female bringing nesting material to one of the bluebird houses along the trail. Female Western Bluebirds are the nest builders and most nests are made out of grasses or pine needles with softer materials lining the nest. Interestingly, like Bushtits, sometimes previous Western Bluebird young will act as helpers, bringing food to their younger siblings.

Other birds of note that we saw were all three species of nuthatch (Red-breasted, White-breasted, and Pygmy), Mountain Chickadee, Pine Siskin, Chipping Sparrow, Ruby-crowned Kinglet, a lone male Mountain Bluebird, and my favorite of the day, two Red-naped Sapsuckers. Sapsuckers are a type of woodpecker that has a specialized tongue to lap sap from trees. They also eat berries and insects and are often found in aspen groves.

We ended up with 28 species, which was a respectable haul for early spring during what has felt like a slow migration year. We hope you can join us on our next walk on June 14th. Until then, don’t stop birding!

Walker Ranch–Meyers Gulch, Boulder, Colorado, US
26 species (+2 other taxa)

Canada Goose 2
Broad-tailed Hummingbird 3
Red-tailed Hawk 1
Red-naped Sapsucker 2
Hairy Woodpecker 1
Northern Flicker 2
Steller’s Jay 1
Black-billed Magpie 2
American Crow 4
Black-capped Chickadee 1
Mountain Chickadee 4
Tree/Violet-green Swallow 1
Ruby-crowned Kinglet 1
White-breasted Nuthatch 2
Pygmy Nuthatch 9
Red-breasted Nuthatch 1
Northern House Wren 4
Western Bluebird 4
Mountain Bluebird 1
American Robin 10
Pine Siskin 2
Chipping Sparrow 3
Dark-eyed Junco (Gray-headed) 2
White-crowned Sparrow 1
Vesper Sparrow 6
Brown-headed Cowbird 2
Yellow-rumped Warbler 2
Yellow-rumped Warbler (Audubon’s) 1

Saturday, February 8, 2025 Bird Walk to Waneka Lake/Greenlee Preserve with Jamie Simo

Posted on February 13, 2025 by frbcadmin - Bird Walks, Blog

This past Saturday morning was blue-cold, but it was definitely worth getting out for the birds. More water was open at Waneka than during my scouting mission, but there were still few water birds around because of the Bald Eagle sitting on the ice busily plucking an unlucky goose. It wasn’t clear whether the goose had already been dead prior to its defeatherstration, but given that Bald Eagles will happily scavenge when given the opportunity, and the rampancy of avian flu in goose populations right now, it’s more than likely.

What was also pretty cool to watch were the Common Ravens coming within inches of the Bald Eagle, a mortal enemy, to take what they could get from the carcass. The Bald Eagle was unbothered, but that wasn’t the case for one American Crow that kept dive-bombing and chasing one of the ravens; ravens will definitely prey on smaller songbirds like crows despite being in the same family group (Corvidae).

White-throated Sparrow (third from left) surrounded by White-crowned Sparrows. Photo by Jamie Simo.

With few ducks and geese about, we spent most of our time looking at songbirds. Sparrows were particularly abundant and it was great to be able to compare White-crowned Sparrows to House Sparrows. At the Greenlee feeders we also were lucky to see the White-throated Sparrow that’s been hanging around and see the difference between it and the White-crowned. Both species are in the Zonotrichia genus, but White-throated Sparrows are mainly found in the east and along the west coast. More are being found along the Front Range every winter, however. While both species have head stripes, White-throated Sparrows have the eponymous white throat as well as yellow lores.

For a cloudy, bitterly cold morning, we had 24 species, which wasn’t bad at all!

Waneka Lake/Greenlee Preserve, Boulder, Colorado, US
24 species

Canada Goose 28
Green-winged Teal 1
Ring-necked Duck 1
Common Goldeneye 1
Eurasian Collared-Dove 1
Ring-billed Gull 15
Bald Eagle 1
Red-tailed Hawk 1
Northern Flicker 5
Blue Jay 8
Black-billed Magpie 1
American Crow 3
Common Raven 5
Black-capped Chickadee 2
White-breasted Nuthatch 2
European Starling 15
American Robin 7
House Sparrow 6
House Finch 2
White-crowned Sparrow 12
White-throated Sparrow 1
Song Sparrow 1
Spotted Towhee 6
Red-winged Blackbird 15

Saturday, January 11, 2025 to White Rocks Trail and North Teller Farms with Carly Crow

Posted on January 21, 2025 by frbcadmin - Bird Walks, Blog

What better way to get through the winter months in Colorado than by taking a sunny birding walk with friends to share the experience? That’s exactly what we did this past Saturday at Teller Lake Ponds.

The Teller Lake Ponds are named after a Colorado senator who once owned a significant amount of farmland in the area. Today, the land is managed by Boulder County, offering miles of trails and plenty of nature to enjoy. Birding here is exceptional year-round.

Prairie dog in the snow. Photo by Jamie Simo.

We had several highlights from our walk this Saturday. We kicked off the morning by watching prairie dogs warm up in the sun, keeping an eye out for any birds in the field. At this time of year, these little rodents have a thick layer of fat and fur, making them appear almost round when they’re above their holes. It’s always a joy to watch the prairie dogs go about their daily routines.

After checking out the colony for sunning raptors or meadowlarks, we made our way north to Boulder Creek. Despite the wind, there was plenty of bird activity to appreciate! We had excellent views of two raptor species: a Red-tailed Hawk and, even more exciting, a Ferruginous Hawk flying overhead. In addition to the birds of prey, we sifted through a flock of Canada Geese and found a trio of Cackling Geese nestled within the group.

Male Hooded Merganser. Photo by Jamie Simo.

Heatherwood Lake had a small patch of open water, where a few Hooded Mergansers and many more Canada Geese were gathered. Across the pond, we spotted a bald eagle nest, where two adult eagles visited during our walk. It’s incredibly exciting to witness the start of the eagle’s breeding season.

Once we reached Boulder Creek, we encountered a mix of diving and dabbling ducks, including Common Goldeneye, Gadwall, Mallard, and a trio of Green-winged Teal. On our walk back, the wind calmed, and we were able to spot a few passerine species, including American Robins, American Goldfinches, and a surprising Brewer’s Blackbird. It was a beautiful walk, and we’re already looking forward to our next outing. The link to our eBird list can be found here: https://ebird.org/checklist/S208882905

Sunday, December 15, 2024 Bird Walk to Sandstone Ranch

Posted on December 17, 2024 by frbcadmin - Bird Walks, Blog

On a beautiful, but windy, Sunday morning, we convened at Sandstone Ranch in Longmont. Sandstone Ranch is named for the sandstone cliffs in the area which formed when Colorado was part of an inland sea. The ranch itself was owned by the Coffin family back in the 1860’s. The original house, which still stands, is currently in use as the park’s visitor center.

Non-breeding American Goldfinch. Photo by Jamie Simo.

Wind is some of the worst weather for birding because it tends to suppress the movement of smaller birds but, happily, around the windbreak of the cliffs we did see some White-crowned Sparrows, an American Goldfinch, and a Northern Flicker. A common misconception is that American Goldfinches migrate because in the winter they’re less visible, being more of a drab olive-brown color rather than yellow. However, they’re resident birds here along the Front Range. Listen for their squeaky little chirps or their “potato chip” flight calls.

Kiting female American Kestrel. Photo by Matt Eagen.

We had several raptors on our walk, including three Red-tailed Hawks, a Northern Harrier, and a very obliging female American Kestrel. Kestrels, our smallest falcon, are one of the few raptors known to hover, meaning they will rapidly flap their wings to remain in place in the air. Hummingbirds also do this as will Belted Kingfishers. However, this particular kestrel wasn’t hovering, but kiting, which is using the wind to stay aloft rather than flapping.

Snow Goose flock. Photo by Matt Robinson.

Finally, we had some great waterfowl. While the majority of ducks we saw were Mallards, we did see both a pair of American Wigeon and Wood Ducks. We also had several thousand Cackling and Canada Geese, a couple of Ross’s Geese, and a good number of Snow Geese in the agricultural fields next to the Peschel Open Space, another natural area adjacent to Sandstone Ranch. Snow Geese are named for their, often, snowy-white plumage, but Snow Geese can also come in a “blue” color phase, where the majority of their feathers are a slatey-grey or “blue” color. Because of the warming of the arctic, Snow Geese are increasing in number rather than declining like many other bird species.

Because of the wind we only saw 18 species, but it was a beautiful day and great company. Hopefully you can join us next time!

Sandstone Ranch (Weld Co.), Weld, Colorado, US
Checklist Comments: Also included Peschel.
18 species

Snow Goose 10
Ross’s Goose 2
Cackling Goose 2000
Canada Goose 100
Wood Duck 2 Pair. Seen last Sunday as well.
American Wigeon 2
Mallard 215
Northern Harrier 1
Red-tailed Hawk 3
Belted Kingfisher 1
Northern Flicker 2
Blue Jay 2
American Robin 1
House Finch 2
American Goldfinch 2
White-crowned Sparrow 4
Song Sparrow 1
Red-winged Blackbird 105

Sunday, November 10, 2024 Bird Walk to Lagerman Reservoir

Posted on November 12, 2024 by frbcadmin - Bird Walks, Blog

We had to push off our usual second Saturday bird walk by a day due to our first snow storm of the season, but I’m so glad we did! It was a perfect bluebird day with sunny skies and a ton of amazing birds!

Lagerman Reservoir is always great for waterfowl and raptors in the fall and winter and it provided the perfect venue for trying out some of our spotting scopes, namely Swarovski’s ATS 65 and Opticron’s new MM4 77. Both scopes provide crystal clear viewing of distant birds. In fact, they were instrumental in determining that the raptor we saw perched out on a fencepost was a Ferruginous Hawk rather than a Red-tailed Hawk. What told us it was the larger Ferruginous Hawk rather than the more common Red-tail, even from far away? The extensive white on the bird’s chest and belly, unbroken by any dark speckling or “belly band,” pale feathers on the head rather than a solid brown head, and a flash of rusty color on the shoulder.

Another special bird of the day was a juvenile Golden Eagle. We could tell the bird was a juvenile Golden Eagle and not a young Bald Eagle by the neat, white patches on the underside of its wings and the way it soared with its wings in a slight V (dihedral). Juvenile Bald Eagles are a messy mix of white and dark brown and soar with their wings flat. While Golden Eagles tend to nest on cliffs or bluffs, they can be found in open country when not breeding, especially in the winter.

For ducks we had quite a few, with the most common being Green-winged Teal, Ruddy Ducks, and Northern Pintails. We even had a late shorebird: a Long-billed Dowitcher, a medium-sized shorebird that passes through Colorado in the spring on its way to breed in the arctic and then back through again in the fall to winter in the southern US and Mexico. Their feeding behavior, which is sometimes described as like a sewing machine, allows them to probe into mud and sand with their long bills in search of invertebrates and mollusks.

With 30 species for the morning, the walk was a great success! We hope you can join us on a future walk!

Lagerman Agricultural Preserve–Lagerman Reservoir, Boulder, Colorado, US
Nov 10, 2024 9:00 AM – 11:50 AM
30 species

Cackling Goose 70
Canada Goose 20
Northern Shoveler 2
American Wigeon 8
Mallard 10
Northern Pintail 25
Green-winged Teal 35
Redhead 15
Ring-necked Duck 4
Lesser Scaup 5
Bufflehead 8
Ruddy Duck 40
Rock Pigeon (Feral Pigeon) 1
American Coot 50
Killdeer 6
Long-billed Dowitcher 1
Ring-billed Gull 4
Eared Grebe 2
Golden Eagle 1
Red-tailed Hawk 3
Ferruginous Hawk 1
American Kestrel 1
Prairie Falcon 1
American Crow 1
Horned Lark 4
European Starling 30
American Pipit 1
American Goldfinch 1
Western Meadowlark 1
Red-winged Blackbird 5

Saturday, October 12, 2024 Bird Walk to Mud Lake with Wild Bear Nature Center

Posted on October 15, 2024 by frbcadmin - Bird Walks, Blog

This past Saturday was October Big Day, the fall counterpart to Global Big Day where people around the world unite to share their love of our avian friends. In celebration of the day, Front Range Birding teamed up with Wild Bear Nature Center for a bird walk around their new nature center site up at Mud Lake Open Space!

Wild Bear Nature Center is Boulder County’s only year-round nature center. Currently located in Nederland in the Caribou shopping center, Wild Bear’s new location, which is currently under construction, sits on 5 acres of land and boasts access to 16 miles of nature trails. It’s designed from the ground up to include state of the art sustainable building practices like bird-friendly glass to prevent collisions and a net-zero energy footprint through the use of solar power.

Wild Bear staff generously provided coffee and donuts for the event and gave us a look at the construction site, though we weren’t able to enter the fence due to safety concerns (you can schedule a special hard hat tour through their website though if you’re interested in a more in-depth tour). After taking a look at the new center, we split up into groups to bird.

Fall starts a quiet time for foothills birding, so we didn’t see many birds on our trek. The most abundant birds were Common Ravens, Pygmy Nuthatches and chickadees, both Black-capped and Mountain.

One of the easiest ways to tell a Mountain Chickadee from a Black-capped Chickadee is by the Mountain’s white “supercilium” or eyebrow. To me, this eyebrow makes the Mountain look somewhat angry. The Black-capped has a full black cap with no white above the eye. Less noticeable, the Black-capped Chickadee tends to have buffier flanks while the Mountain is more grey overall. Their calls are also different, though this can be hard to hear. The Mountain’s chicka-dee-dee call is raspier, almost like it has a sore throat.

Black-capped Chickadee. Photo by Jamie Simo

Although not a bird, we’re equal opportunity when it comes to nature here at FRBC and the highlight of the trip was definitely the muskrat we saw in Mud Lake. Often mistaken for beavers, muskrats are much smaller (up to around a foot long versus up to 3 feet long, and 2-4 pounds versus an average of 40 or so pounds). While beavers have a flat, paddle-shaped tail, muskrat tails are long, thin, and slightly vertically flattened. Beavers are strictly herbivorous, meaning they only eat plants such as leaves, shoots, and the inner bark of trees. Muskrats, however, are omnivorous so, in addition to aquatic plants, they’ll also eat crayfish, frogs, and small fish. There aren’t any fish in Mud Lake, so perhaps they’re chowing down on tiger salamanders and chorus frogs.

American beaver. Photo by Dona Hilkey. https://flic.kr/p/w4CUW7

While we only had 8 species for the morning, the good company was more than worth it. We look forward to partnering more with Wild Bear’s staff!

Mud Lake Open Space, Boulder, Colorado, US
8 species

Steller’s Jay 1
Black-billed Magpie 1
American Crow 1
Common Raven 4
Black-capped Chickadee 3
Mountain Chickadee 3
Pygmy Nuthatch 4
Dark-eyed Junco 1

Saturday, July 13, 2024 Bird Walk at Meyers Gulch Trail with Owen Robertson

Posted on July 13, 2024 by frbcadmin - Bird Walks, Blog

Participants had to brave the heat for this month’s bird walk at Meyers Gulch, but were rewarded with a host of montane birds at this beautiful location on the west side of Flagstaff Mountain in the Walker Ranch area. The trail begins by passing through Ponderosa Pine savannah (open grasslands with scattered trees), then passes by a creek flanked by willows, Douglas Fir, and Colorado Blue Spruce. It’s a great place to find characteristic species of Colorado’s foothills, while the mix of habitats mean surprises are always possible.

The walk began with a mixed flock of Tree and Violet-green Swallows soaring over the parking lot – a unique sight in the mid-elevation habitats where these two species overlap. Identifying these species, while difficult on rapidly flying birds, is straightforward – Violet-greens have a distinct white rump band and pale face while, conversely, Trees have a solid blue rump and darker face. Meanwhile, dainty Pygmy Nuthatches flitted around in the canopy of nearby Ponderosa Pines and plentiful Vesper Sparrows (a prairie bird making use of the savanna-type habitat) serenaded us with their trilling songs.

**Mountain Bluebird. Photo by Jamie Simo**

A little further on, a gorgeous male Mountain Bluebird was spotted perching some distance away. This species is equally at home in alpine tundra or lowland prairie, and afforded us an opportunity to study the differences between it and the male Western Bluebird that we found nesting nearby – paler blue coloration with no rufous on the chest or back. The forest, though, harbored a different set of birds: Western Wood-Pewees caught insects from the tops of fir trees while Western Flycatchers, audible though not visible, gave their trademark whi-deet song from deep in the trees.

The highlight, however, was a stunning male Western Tanager that showed off its bright yellow and red plumage for the entire group to enjoy. The birds didn’t stop on the way back, either, with a singing Warbling Vireo (of the distinct “Western” vocal type) staying hidden in the canopy and an exciting mixed flock of bluebirds and Steller’s Jays keeping us busy. All in all, it was a thoroughly enjoyable walk, with good birds and great people in an incredible location!

Meyers Gulch Trail
July 13, 2024
25 species

Eurasian Collared-Dove – 1
Mourning Dove – 2
Broad-tailed Hummingbird – 4
Turkey Vulture – 1
Northern Flicker – 1
Western Wood-Pewee – 7
Western Flycatcher – 3
Warbling Vireo – 1
Steller’s Jay – 3
Common Raven – 1
Mountain Chickadee – 6
Tree Swallow – 5
Violet-green Swallow – 16
White-breasted Nuthatch – 3
Pygmy Nuthatch – 14
House Wren – 6
Western Bluebird – 9
Mountain Bluebird – 1
American Robin – 4
House Finch – 1
Chipping Sparrow – 3
Dark-eyed Junco – 3
Vesper Sparrow – 8
Green-tailed Towhee – 1
Western Tanager – 4

Saturday, June 8, 2024 Bird Walk to Button Rock Preserve with Jamie Simo

Posted on June 13, 2024 by frbcadmin - Bird Walks, Blog

Button Rock Preserve, located about 7 miles outside of Lyons, Colorado, is a 2,691 acre protected area where Longmont, Colorado, gets the majority of its drinking water. The preserve opened to the public in 1965 and it’s a fantastic place to get up into the mountains and bird. FRBC has never done a bird walk at Button Rock before, but I’d been wanting to since last fall and spring/early summer is an ideal time to hear and see mountain migrants.

Right off the bat we were treated to views of Violet-green Swallows swooping over the St. Vrain in search of insects. Violet-green Swallows breed at higher elevations than Tree Swallows, but like Tree Swallows, will nest in tree cavities. They’ll also nest in cliffs and we did see a few dip into some crags in the rock walls bordering the St. Vrain. Males are particularly beautiful with bright emerald green backs and purple tails.

Violet-green Swallow. Photo by Jamie Simo.

We also were able to watch an American Dipper searching for macroinvertebrates, giving its eponymous tail “dip.” One cool thing about them is that their eyelids are covered with white feathers. Apparently this allows dippers to signal to one other when the rush of the water may prevent them from being able to hear each other. Other species we were lucky enough to get some great views of were both male and female Western Tanagers, a singing Lazuli Bunting, and Cedar Waxwings. Less visible but heard species included Hammond’s Flycatcher, Pine Siskin, and Macgillivray’s Warbler.

While we understandably focus mostly on birds on our bird walks, being a naturalist means anything is fair game! Because the participants of this walk were particularly interested in plants and insects, we spent a lot of time taking in the wildflowers, trees, and butterflies/moths along the dam road. This Melissa blue butterfly was especially cooperative, perching long enough for us to get some good photos. Lupines are among their host plants.

Melissa blue butterfly. Photo by Jamie Simo.

Among the flowers we saw were Lambert’s locoweed (Oxytropis lambertii), which is in the pea family and is poisonous. The toxic compound in the plant is called swainsonine and, when ingested in large enough quantities by livestock, can prevent the absorption of needed nutrients and potentially cause neurological damage (the reason for the common name locoweed).

Lambert’s locoweed. Photo by Jamie Simo.

A beautiful morning for a walk and a beautiful place for a walk! I encourage you to check out Button Rock Preserve. Just a reminder, no bikes or dogs are allowed. Happy birding!

Button Rock Preserve, Boulder, Colorado, US
26 species

Canada Goose 2
Common Merganser 2
Broad-tailed Hummingbird 3
Great Blue Heron 1
Belted Kingfisher 1
Northern Flicker 2
Western Wood-Pewee 2
Hammond’s Flycatcher 2
Western Flycatcher (Cordilleran) 1
Mountain Chickadee 1
Violet-green Swallow 12
Barn Swallow 1
Rock Wren 2
House Wren 2
American Dipper 2
Gray Catbird 1
American Robin 10
Cedar Waxwing 5
Pine Siskin 2
Lesser Goldfinch 3
Chipping Sparrow 2
Song Sparrow 1
MacGillivray’s Warbler 3
Yellow Warbler 3
Western Tanager 7
Lazuli Bunting 3

Saturday, May 11, 2024 Bird Walk to Golden Ponds with Jamie Simo

Posted on May 17, 2024 by frbcadmin - Bird Walks, Blog

I maintain there is no better month in Colorado than May, and Golden Ponds is a fantastic place to enjoy spring unfolding. Like most of the ponds in the state, Golden Ponds is the product of reclamation following gravel mining. The first pond closest to the parking lot is a good one for American White Pelicans in the spring and summer and we saw several of those right off the bat. Historically, pelicans would mainly pass through Colorado on their way north to breed, but the addition of so many ponds and reservoirs means they now breed in several places within the state. The bumps on their bills are called caruncles and have some function in courtship that scientists don’t entirely understand yet. Both sexes show them in the breeding season.

Golden Ponds is one of the areas where Eastern Phoebes return each year to breed. As their name suggests, Eastern Phoebes are commonly found in the eastern United States and midwest, but the increase in tree canopy in Colorado within the last several decades have allowed these birds, as well as birds like the Blue Jay, to start colonizing further west. Eastern Phoebes are a brown flycatcher that often sits out in the open. It says its name: “Phoebe!” and bobs its tail regularly. There’s been one hanging around near the footbridge over St. Vrain Creek near the Beckwith diversion structure for a few weeks now.

Other migrants we were able to see and/or hear were Yellow Warblers, Yellow-rumped Warblers, and a male Bullock’s Oriole that helpfully perched low for us to get a decent look. Less accommodating was a Warbling Vireo that we could hear singing, but hid in the tree canopy out of sight.

As expected, nesting birds were plentiful, including a pair of Bushtits constructing their pendulous nest, which looks like a messier version of an oriole’s nest, with moss, grasses, and conifer needles woven together with spider webs. Both Cooper’s and Red-tailed Hawks were also on their nests with the Red-tailed Hawk having a downy chick already.

Finally, of special note were the amorous pair of Spotted Sandpipers who we saw copulating. Unlike most birds, it’s the male that will do the incubating and chick-tending while the female may go off to establish another territory and another nest with one or more additional males.

Another great bird walk! We’ll see you again in June!

Golden Ponds Park and Nature Area, Boulder, Colorado, US
36 species (+1 other taxa)

Canada Goose 6
Mallard 3
Mourning Dove 3
Killdeer 1
Spotted Sandpiper 2
Double-crested Cormorant 3
American White Pelican 20
Great Blue Heron 2
Turkey Vulture 7
Osprey 1
Cooper’s Hawk 1
Red-tailed Hawk 1
Downy Woodpecker 2
Northern Flicker 3
American Kestrel 1
Eastern Phoebe 1
Warbling Vireo 1
Blue Jay 3
Black-capped Chickadee 2
Tree Swallow 1
Barn Swallow 5
Bushtit 2
White-breasted Nuthatch 1
House Wren 2
European Starling 1
American Robin 6
House Sparrow 4
House Finch 5
American Goldfinch 5
Song Sparrow 6
Bullock’s Oriole 1
Red-winged Blackbird 28
Brown-headed Cowbird 7
Common Grackle 5
Yellow Warbler 2
Yellow-rumped Warbler 4
Yellow-rumped Warbler (Audubon’s) 1

Saturday, April 13, 2024 Bird Walk to Stearn’s Lake with Jamie Simo

Posted on April 17, 2024 by frbcadmin - Bird Walks, Blog

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 Matt Eagen.

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.

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

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