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

June 13, 2024

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.

American Dipper. Photo by Jamie Simo.

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


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