Erickson’s April 2022 Site Update

What an interesting spring it’s been so far! Some days it’s been in the upper 70s, other days the temperature starts out at 16°F, and regardless of the weather, we’ve been having a ton of windy days and not a lot of precipitation. Nevertheless, if you’ve been to Bluff Lake recently you’ll see the grassy areas slowly getting greener, and leaves beginning to show on the rabbitbrush. Out in the cattails, the small brown heads of new plants are starting to poke up through the last year’s dried plants. I’m looking forward to seeing the site bursting with new colors as the season wears on!

The warmer weather has allowed us to do more on the site, and we’ve been busy with a wide variety of projects. Graland Country Day School has been to the site twice this month to complete service learning projects with us. One day, Graland 8th graders helped us plant 22 pounds of native grasses, shrubs, and wildflowers in an effort to restore vegetation on a hillside next to the lake that had been denuded by prairie dogs. In addition to providing habitat for many species, we hope this vegetation will stabilize the hillside and prevent sediment from eroding into the lake. Just this week, Graland students returned to Bluff Lake to paint the bases of trees along Sand Creek with a mixture of water-based, non-toxic latex paint and sand to project the trees from being cut down by beavers. Though beavers are a native species and a valued presence in this landscape, we also want to preserve some of our riparian woodlands that provide cover for many species, stabilize soils adjacent to the creek, and provide shade for our visitors along the trails. We didn’t paint all the trees, so the beavers should be able to find a few snacks!

Graland students paint a tree with a paint/sand mixture to protect it from beaver activity along Sand Creek.

Mile High Youth Corps (an Americorps program) has been visiting Bluff Lake twice a week to assist with a variety of projects, from preparing and deploying materials for wildlife surveys, to clearing downed tree limbs from last season and repurposing them to close social trails, demarcate the boundaries of the play areas, and create structures in the prairie dog colony along our southern boundary. We are experimenting by building “blinds” in the prairie dog colony, with the hopes that providing cover will help the success of predators like coyotes and foxes, which can help us naturally manage our prairie dog populations.

Mile High Youth Corps members cut and load downed limbs into the BLNC truck to repurpose in several projects around the site.

Our most consistent habitat restoration volunteer group, the Weed Warriors, has started up for the season this month. So far, we have been focusing on removing poison hemlock, cutleaf teasel, common burdock, houndstongue, and curly dock rosettes as the plants begin to grow. All of these plants are invasive species, which means that they are not native to Colorado, and “behave” in such a way that outcompetes our native plants and can often contribute to a decrease in biodiversity and lessen the value of certain habitats for wildlife. We are excited to see so many returning faces, and to welcome several new faces. If you’d like to get involved with Weed Warriors, please email me at erickson@blufflake.org for more information! We meet on Friday mornings from 9 a.m.-12 p.m. in the spring and fall, and 8 a.m.-11 a.m. in the summer to beat the midday heat.

Young poison hemlock plant (not a carrot!)

Cutleaf teasel rosette.

As we see more and more humans visiting the site, we’re also seeing an increase in animal activity with the warmer weather! A great horned owl nest has successfully hatched two young, and we look forward to their fledging. Red-tailed hawks may also be nesting at Bluff Lake, and just recently we’ve begun seeing Swainson’s hawks that are back in Colorado after spending the winter in South America! We love seeing visitors birding at Bluff Lake, and we want to make sure the birds are just as happy to see us! Please remember to give birds their space: don’t leave trails to approach birds and their nests. As a wildlife refuge, we want to make sure that the species that live here are able to carry out their natural histories without too much interference from us humans. If you get a great photo of a bird or other animal from a safe distance, we’d love to see it submitted to eBird or iNaturalist, or you can email it to us at info@blufflake.org. Happy wildlife viewing!

A great horned owl on its nest with a nestling (small white form to the left of the adult). Photo taken through binoculars.

Our game cams have been very active, check out some of the clips of animals we’ve seen!