As Saturday’s participants will attest Beaver Ranch, which is operated and managed by a local non-profit in agreement with Jeffco Open Space, is an “interesting” place.  It provides cabin rentals, camping sites, a disc golf course, and multiple ziplines; and occasionally weddings are held there.  So, on a summer Saturday morning it’s pretty much guaranteed to be a bit of a zoo.  However, if you get there early enough and know which paths to take, it has a nice diversity of habitats and birds.

For starters, Casto Creek which runs through the north side of the ranch transects a wide, open mountain meadow with occasional huge ponderosas along one side and dense stands of spruce, Douglas-fir, and aspen on the opposite.  Then, it has a wide swathe of tall willows running the whole way along the creek.  The height and extensiveness of these willows is part of what makes Beaver Ranch exceptional with regard to the birds that can be seen there, and for starters, we saw a Yellow Warbler and a Lincoln Sparrow.  Generally, Yellow Warblers nest in streamside habitat of the plains and lower foothills while Lincoln’s Sparrows nest in willow shrublands of the montane, subalpine, and alpine ecosystems.  At Beaver Ranch the two species get to overlap.  Also, in the willows were a Song Sparrow and a singing Black-headed Grosbeak – one of Colorado’s premier vocalists.  Meanwhile, out in the meadow a pair of Tree Swallows were exploring the possibility of raising young in a bird box.  Last year, at this time a pair of Tree Swallows was already feeding young at this same box.  Our late May snow events have apparently delayed the start of nesting this year.  In this same vicinity we also saw a pair of Red-tailed Hawks, a Say’s Phoebe, a Barn Swallow, a few Mountain Bluebirds, a White-crowned Sparrow, and some Pine Siskins.

Leaving Casto Creek we followed a small tributary, not much more than a foot wide, into a narrow valley dominated in the bottom by huge blue spruce, with Douglas-fir on the north-facing slope and ponderosas on the south-facing slope.  A major feature was the occasional patches of mature aspen, which can provide groceries and condo-style living for a wonderful variety of birds.  Here we had nesting Violet-green Swallows and House Wrens – both being secondary cavity nesters (using cavities created by birds capable of excavating holes – woodpeckers and nuthatches).  It was here that we also got fantastic looks at a Red-naped Sapsucker, a Warbling Vireo, a Western Tanager, and a MacGillivray’s Warbler – these last two being among my favorite birds!  Throughout our time in this little valley, we were treated to the ongoing singing of Cordilleran Flycatchers, House Wrens, and Ruby-crowned Kinglets, and, YES, at least one participant got to see the ruby crown!

What a glorious morning!
Chuck

Beaver Ranch, Jun 4, 2022
38 species

Mourning Dove  1
Broad-tailed Hummingbird  4
Turkey Vulture  5
Red-tailed Hawk  2
Red-naped Sapsucker  1
Hairy Woodpecker (Rocky Mts.)  1
Western Wood-Pewee  1
Cordilleran Flycatcher  5
Say’s Phoebe  2
Warbling Vireo  1
Steller’s Jay (Interior)  3
Black-billed Magpie  2
American Crow  1
Common Raven  2
Mountain Chickadee  6
Tree Swallow  6
Violet-green Swallow  5
Barn Swallow  3
Ruby-crowned Kinglet  8
Red-breasted Nuthatch  1
White-breasted Nuthatch  2
Pygmy Nuthatch  1
House Wren  4
Mountain Bluebird  3
American Robin  10
House Finch  1
Pine Siskin  3
Chipping Sparrow  2
Dark-eyed Junco (Gray-headed)  1
White-crowned Sparrow (oriantha)  1
Song Sparrow  3
Lincoln’s Sparrow  3
Red-winged Blackbird  8
Brown-headed Cowbird  1
MacGillivray’s Warbler  1
Yellow Warbler  4
Western Tanager  1
Black-headed Grosbeak  3