Pella Crossing Open Space encompasses a collection of former gravel-mine ponds to both the east and west of N 75th Street in Hygiene, Colorado. The portion of the open space west of N 75th Street also includes a short stretch of Saint Vrain Creek on its way to Longmont. The water features and riparian habitat attract many interesting bird species at all times of year. We were greeted by a calm and bright spring morning for our May 14, 2022 second Saturday bird outing to the Marlatt Trails on the western portion of Pella Crossing Open Space.
Spring migration and the beginning of the breeding season was already in full swing at Pella Crossing. Many of the northern Front Range resident species were beginning to start their annual breeding rituals, with Red-winged Blackbird males vigorously chasing females, House Finches carrying nesting material, courtship feeding between a pair of Black-capped Chickadees, and a female American Robin already incubating on a nest. Two pairs of Osprey, which migrate here to breed from points south, occupied two separate nest platforms at opposite ends of the western half of Pella Crossing, both females incubating and one of the males continuing to bring nesting material. The Great Blue Heron rookery next to Saint Vrain Creek sounded active, which is to say that we heard Great Blue Herons in that direction, but we could not see birds at nests because the trees were already leafing out.
The real stars of the day’s show, however, were the summer breeders who winter far to the south of Colorado, and the spring migrants visiting briefly on their way to breeding grounds in points north or in higher elevations. A number of northern Front Range summer-visiting songbirds like House Wrens, Gray Catbirds, Bullock’s Orioles, Yellow Warblers, and four species of swallows (Tree, Barn, Cliff, and Northern Rough-winged) delighted us with their cheerful songs and bright colors. A few species were just passing through, still yet to reach their breeding grounds. Among them, a skulky Lincoln’s Sparrow giving its buzzy call, a flamboyant male Western Tanager, and a handsome male MacGillivray’s Warbler (whose name, the group decided, is a mouthful to say!).
Speaking of warblers, two of the biggest highlights of the day were undoubtedly warblers. First, the aforementioned MacGillivray’s Warbler (say it again with me!), which we stayed on for several minutes as it furtively fed along a stand of Russian Olives until everyone in the group got a definitive look – which is saying something indeed for a small, busy, and camouflaged bird uninterested in showing off! The second fabulous warbler we saw was a female-type Northern Parula, which is an unusual sight in our area, as the bulk of their migration path falls far to the east of Colorado’s eastern border with Kansas. This bird was fairly dull-colored even for a female Northern Parula, and may have been a first-year female hatched last summer, now making her first northward migration.
We had a fun group of birders brimming with enthusiasm on our May 14th outing – I thoroughly enjoyed sharing the morning and the birds with you all. My only regret is that with all the interesting birds popping up all around, I didn’t have enough time to answer all your questions and continue all the conversations! Please drop Front Range Birding Company a line at email@example.com if you still have burning questions – we touched on a lot of topics like species concepts, hybrids and intergrades, status and distribution of many bird species, and distinguishing between similar species. One of my favorite birds to share with you (and one which spoke to all of those aforementioned topics) was a male Northern Flicker that showed characteristics of being an intergrade between the western “Red-shafted” form and the eastern “Yellow-shafted” form. The two forms are so visually different that they were once considered separate species. On the Front Range of Colorado, the two forms meet and produce an intergrade zone of Northern Flickers that display a spectrum of plumage traits from both forms. Our particular male flicker was a textbook example of such an intergrade, with a bright red malar stripe (“mustache”) from its red-shafted ancestors, and a red nuchal/nape patch on the back of the head from its yellow-shafted ancestors. These intergrade Northern Flickers remind us to look closely at even the most common birds around us – they can be just as fascinating as the rare birds that show up during migration seasons!
See you next time – let’s go birding!
36 species observed, 188 individuals
Canada Goose (Branta canadensis) 8
Mallard (Anas platyrhynchos) 1
Eurasian Collared-Dove (Streptopelia decaocto) 2
Mourning Dove (Zenaida macroura) 1
Double-crested Cormorant (Nannopterum auritum) 10
American White Pelican (Pelecanus erythrorhynchos) 1
Great Blue Heron (Ardea herodias) 5
Turkey Vulture (Cathartes aura) 5
Osprey (Pandion haliaetus) 4
Bald Eagle (Haliaeetus leucocephalus) 1
Northern Flicker (Yellow-shafted x Red-shafted) (Colaptes auratus luteus x cafer) 1
Eastern Kingbird (Tyrannus tyrannus) 4
Warbling Vireo (Vireo gilvus) 1
Blue Jay (Cyanocitta cristata) 3
Black-capped Chickadee (Poecile atricapillus) 4
Northern Rough-winged Swallow (Stelgidopteryx serripennis) 1
Tree Swallow (Tachycineta bicolor) 2
Barn Swallow (Hirundo rustica) 4
Cliff Swallow (Petrochelidon pyrrhonota) 1
House Wren (Troglodytes aedon) 4
European Starling (Sturnus vulgaris) 10
Gray Catbird (Dumetella carolinensis) 4
American Robin (Turdus migratorius) 6
Cedar Waxwing (Bombycilla cedrorum) 2
House Finch (Haemorhous mexicanus) 6
American Goldfinch (Spinus tristis) 2
Song Sparrow (Melospiza melodia) 3
Lincoln’s Sparrow (Melospiza lincolnii) 1
Bullock’s Oriole (Icterus bullockii) 3
Red-winged Blackbird (Agelaius phoeniceus) 40
Brown-headed Cowbird (Molothrus ater) 11
Common Grackle (Quiscalus quiscula) 25
MacGillivray’s Warbler (Geothlypis tolmiei) 1
Northern Parula (Setophaga americana) 1
Yellow Warbler (Setophaga petechia) 9
Western Tanager (Piranga ludoviciana) 1
View this checklist online at
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