Boulder County Wildlife's Journal

The 2021 City Nature Challenge will be here before we know it! Help us show the world how biodiverse our region is by documenting observations of wild plants and animals from April 30 – May 3, 2021. Document nature in your home, backyard, neighborhood, or nearby parks or trails, and upload your observations to iNaturalist. Any observations of wild plants, animals, and fungus found throughout the Denver-Boulder region will count.

Last year, the Denver Metro Area competed against 244 cities throughout the globe and came up with some impressive numbers:

• 5,847 total observations
• 838 plant and wildlife species identified
• 443 observers
• 373 identifiers

Throughout the globe, 41,165 observers from 244 cities collected 814,258 observations of 32,500+ species (including more than 1,300 rare/endangered/threatened species) during the four-day bioblitz! Read more about the 2020 results and view some of the standout observations from the Denver-Boulder region.

The first four days, April 30 – May 3, are the days that observations will be collected (aka the bioblitz), and the last six days, May 4 – May 9, are when those observations will be identified and verified. Participants can also continue to upload observations during this six-day period as long as the sightings took place during April 30 – May 3.

You can make observations anywhere wild nature exists: explore your backyard and neighborhood, city and neighborhood parks, open space, mountain parks, and natural areas, state parks, urban areas, and more! In light of the COVID-19 pandemic, we ask that participants please be respectful of all people and wildlife around you, follow all social distancing requirements, and abide by local land and facility closures. Avoid overcrowded areas and instead visit popular trails during off days/times. 

Learn how you can get involved by visiting wild.org/naturechallenge and joining our City Nature Challenge project on iNaturalist. Can't wait to see your observations!

By Dave Hoerath, Wildlife Biologist with Boulder County Parks & Open Space

When we hear the word wildfire these days it makes us cringe. We think of the Hayman Fire or Waldo Canyon Fire or Fourmile Fire and the toll on the human environment. Now we add Cameron Peak, East Troublesome, and CalWood fires, all with more tragic human consequences. But the CalWood Fire hit very close to home, burning 4000+ acres of our treasured Heil Valley Ranch. How do fires like these - and this one, affect wildlife?

Turkeys returning to burned areas in Heil Valley Ranch

The ponderosa pine forest ecosystem evolved with periodic fire and the burn effects of most fires are just part of the deal. Unfortunately, the CalWood Fire was a bit more intense than the normal range of fires affecting montane forests. The drouthy conditions, winds, temperature, and the fire's own heat created some severe fire behavior and severe impacts, burning whole trees, whole stands of trees, and the duff and soil beneath them. Those high severity areas aren't much for habitat anymore—unless you are a forest insect or bird that feeds on them. Conditions will be very good for that suite of species for the next few years.

But for many other species, ”home” is gone. Small mammals may have been able to get into rocks or the duff layer or those pockets of forest that didn't burn severely. But surely many animals did not make it out of the path of the fast-moving flames and toxic smoke. Abert's squirrels may have been particularly hard-hit at Heil Valley Ranch, directly and indirectly. Much of the good habitat that was occupied by squirrels is now torched matchsticks. It won't be Abert's squirrel habitat for a very long time. In fact, some areas may not revert to forest, due to the effects of climate change and the lack of seed source. We may get some conversion to grassland or shrubland as we have seen in recent severe Boulder County fires like Black Tiger, Walker Ranch, and the Overland Fire.

Mule deer © Kevin Grady

Luckily enough of a late fall fire doesn't directly affect the songbird population, which has already migrated. Birds, in general, just fly out of the burn zone and come back after the fire. However, of the returning migrants next spring, many will be forced to go somewhere else or be shoe-horned into the unburned fingers and patches of the CalWood Fire. Most larger mammals are also mobile enough to avoid fires and flamefronts. In the dark and confusion of the fire, and the difficult terrain, we have discovered some mortality in those large mammals. But we have also seen deer, elk, and turkeys back in the burned areas at Heil Valley Ranch. That habitat is likely in less-than-optimal condition. They too will likely be forced to use different areas or larger areas to make up for the habitat altered by the fire. They are lucky that portions of Heil Valley Ranch are closed to the public and that portions of the area burned will also be closed temporarily (for safety) to give them some time and space to adjust and recover.

With the 2020 Denver-Boulder City Nature Challenge now just one week away (April 24 - May 3, 2020), we wanted to provide some updates on the current status of the event due to the COVID-19 pandemic.

The event from April 24th- May3rd is still taking place however, this year the City Nature Challenge will no longer be a competition between cities but rather a collaborative initiative among cities that harnesses the healing power of nature. This will allow people to safely document biodiversity in whatever way they can, even from the safety of their own homes if necessary. We urge all participants to carefully follow public health guidelines provided by your local governments, as they are changing in real-time. For more information, please visit our website: wild.org/naturechallenge and download our City Nature Challenge Guide. 

In light of the COVID-19 pandemic, we will no longer be hosting or promoting any group activities. We encourage all individual participants to explore nature in their close to their homes*. If you have trails and open spaces in your neighborhood, that’s great! Please check the status of all parks and open spaces before visiting. Please be respectful of all people and wildlife nearby, follow all social distancing requirements, and abide by local land and facility closures. Please avoid overcrowded areas.

Remember that your own backyard is teeming with wild nature! Your home is a complex ecosystem and contributor to the larger landscape. Be sure to spend lots of time in your yard and/or neighborhood exploring the diversity of plants, birds, insects, mammals, and other wildlife coming through at all hours. Have fun, and be safe!

*If you are concerned about revealing the location of a sensitive organism (or where your house is), you can hide the exact location from the public by changing the “geoprivacy” of the observation to “obscured.”

The Denver-Boulder City Nature Challenge is organized by the WILD Foundation, Colorado Parks & Wildlife, The Nature Conservancy, Denver Botanic Gardens, Denver Audubon, and Denver Metro Nature Alliance.

Get ready: the 2020 City Nature Challenge is coming up in April, and we need YOU to help us show the world just how wild the Denver-Boulder region is!

From April 24 – May 3, 2020, Boulder County and the Denver Metro Area are teaming up to compete in this year’s City Nature Challenge (CNC)! Last year, our region came up with a whopping 6,211 total observations, 970 identified plant and wildlife species, and had 406 observers and 259 identifiers.

There is nature all around us, even in our cities. Knowing what species are here and where they are helps us study and protect them, but the ONLY way to effectively do that is by working together (scientists, land managers, community members, you name it) to find and document nature in our area. By participating in the CNC, not only do you learn more about local nature, but you can also make our urban areas a better place – for you and our wild neighbors!

The competition will take place in two phases: the first four days, April 24 – 27, are the bioblitz. We need you all to get out and document as many plant and wildlife observations via iNaturalist as possible. During the last six days, April 28 – May 3, participants can upload their observations taken during the bioblitz, and help identify and verify observations. The Boulder-Denver Metro Area City Nature Challenge encompasses Adams, Arapahoe, Boulder, Broomfield, Denver, Douglas, and Jefferson Counties.

To receive updates, join the iNaturalist project. Since the project is set up as a bioblitz, all you need to do is upload your observations taken during the April 24 – 27 timeframe by May 3rd at 11:59pm and they’ll automatically be counted. If you observe any species of wildlife throughout Boulder County, remember to continue adding to the Boulder County Wildlife Project, too!

We have some awesome prizes available to participants this year, ranging from REI’s Flash 18 Print Backpacks, nature photography coffee table books, trail guides, and more. Make sure you set aside some time to get outside! And bring a friend or family member along, will ya?!

For more information about the Denver-Boulder CNC and to learn about events in the area, check out this page and follow us on Facebook. Questions? Contact Melanie Hill at the WILD Foundation, melanie@wild.org.

When spring springs, thousands of water birds leave their southern homes for the breeding grounds of the north. Many stop over in Boulder County on our ponds, creeks and reservoirs. Although most of these birds are just taking a break from their long journey before continuing northwards, some will stay in the area to breed.

Late February and March are great times to go duck watching. Sawhill and Walden Ponds, Baseline and Lagerman Reservoirs, or the ponds at Pella Crossing offer some of our best spring birdwatching.

Expect to find gadwalls and wigeons, mallards and several kinds of teal, northern shovelers, and maybe a pintail or a wood duck! You may see these ducks in shallow water, tipping their bottoms up into the air while their feet kick furiously. This behavior, called dabbling, lets the ducks pick food off the shallow bottom of the pond.

Photo: A Cinnamon Teal takes flight. Photo by DP Lawrence, visit his profile here: 
https://www.inaturalist.org/people/dplawrance

Also watch out for diving ducks, which prefer deeper water: redheads, buffleheads, groups of mergansers and goldeneyes, and elegant canvasbacks. The divers will disappear underwater sometimes for up to a minute as they swim about using their strong feet for propulsion. Just when you think they have gone, one will pop up suddenly like a cork. By feeding in deep waters, these ducks avoid competition for food with their dabbling cousins.

Climate change may affect the timing of spring migration. By documenting ducks on the move with iNaturalist, you are helping to build a data set that supports scientists as they track changes to migration patterns over time. We look forward to seeing your observations!

There is nothing quite like the eerie bugle of a bull elk in the fall. Fall is also the best time to see them. It is the breeding season—the rut—and elk can be very much on display without much concern for humans or whatever else is going on around them. Cows, calves, and bulls are all out and about as the bulls compete for the cows, and build and defend harems. Mature bull elk will “spar” with like-sized and antlered elk to determine dominance. Smaller bulls will do the same for practice, as they will have no access to the females.

Fall colors abound as well: the yellows, greens, and oranges of aspen; the blood red sumac, Virginia creeper, and poison ivy; the shiny golden hairs of the curling mountain mahogany seeds; yellows and greens of riparian willows and cottonwoods; the fading gold of grassy fields; and the occasional patch of snow from an early storm.

Boulder County Parks & Open Space properties where you can see (and hear) elk include: Heil Valley Ranch, Hall Ranch, Ron Stewart Preserve at Rabbit Mountain, Mud Lake & Caribou Ranch, and Walker Ranch. Best times for bugling are the cooler mornings and late afternoons, or any overcast/rainy day in late September/early October. Stay safe: on-trail and on-leash. Elk might not be the only thing you see out there that is big and scary. Bears are in their eat-everything-around-the-clock mode and those higher elevation properties have moose as well. Your cameras will have a field day no matter what you see! Post your best here on the Boulder County Wildlife Project on iNaturalist.

Butterfly populations peak in July and August across Boulder County. On just about any hike you'll notice many different species, since the Front Range has some of the highest butterfly diversity in the United States! Butterflies are most active on warm days in ​the late morning and afternoon.

They often congregate in flower-filled meadows and in low-lying muddy areas where small streams cross trails. Another great place to see butterflies is at the top of mountains, where they congregate to find mates. On a hot afternoon, the summit of Green Mountain swarms with butterflies! Butterflies feed on nectar which they gather from flowers with their long, hollow tongue or proboscis. They keep the tongue rolled up in a tight coil while flying. When a butterfly alights on a flower to feed, special muscles at the base of the proboscis force high pressure fluid into the tongue, causing it to elongate. The butterfly can then probe the depths of a flower in search of nectar, much like a kid slurping the dregs of a soda bottle with a long straw.

​Look for the famous orange and black monarch butterflies, which will be migrating through the Front Range. Monarchs feed on plants in the milkweed family - the larvae eat the leaves, and the adults seek nectar from the flowers (see photo). Although they don't frequently breed in the Boulder area, stay on the lookout for the distinctive yellow, black and white striped caterpillars, or the jewel-like green chrysalises dangling from the leaf of a milkweed. If you want to help monarch populations, grow milkweed plants in your own garden! 

Boulder County’s historic Walker Ranch homestead was the site of this year’s historic preservation Youth Corps team project. Every year Youth Corps members work on numerous county projects that help staff complete the busy summer work load. On June 26, a team leader found a small brown/tan cocoon object attached to the bottom of an old piece of barn wood that was going to be thrown out. It was identified by another member as a praying mantis egg case.

Not wanting to damage the case, and crossing their fingers for a cool educational moment, the egg case was gently set aside to keep it out of the work area and risk being damaged. Minutes after it was set down in the shade, it started to wiggle to life.

Nearly all at once 60 to 80 mantises emerged from the case and headed off in all directions. Photos were taken by iNaturalist photographer Mike Lohr and submitted to the Boulder County Wildlife project on iNaturalist for all to see!

From April 26 – May 5, 2019, Boulder County and the Denver Metro Area are teaming up to compete in this year’s City Nature Challenge (CNC)! Last year, Boulder competed independently and came up with a whopping 3,478 total observations, 784 identified plant and wildlife species, and had 107 observers. This year, Boulder County and the Denver Metro Area are joining forces to show the world just how biodiverse our region is, and we need YOU to help!

There is nature all around us, even in our cities. Knowing what species are here and where they are helps us study and protect them, but the ONLY way to effectively do that is by working together (scientists, land managers, community members, you name it) to find and document nature in our area. By participating in the CNC, not only do you learn more about local nature, but you can also make our urban areas a better place – for you and our wild neighbors!

The competition will take place in two phases: the first four days, April 26 – 29, are the bioblitz. We need you all to get out and document as many plant and wildlife observations via iNaturalist as possible. During the last six days, April 30 – May 5, participants can upload their observations taken during the bioblitz, and help identify and verify observations. The Boulder-Denver Metropolitan Area City Nature Challenge encompasses Adams, Arapahoe, Boulder, Broomfield, Clear Creek, Denver, Douglas, Elbert, Gilpin, Jefferson, and Park Counties.

To receive updates, join the iNaturalist project. Since the project is set up as a bioblitz, all you need to do is upload your observations taken during the April 26 – 29 timeframe by May 5^th at 11:59pm and they’ll automatically be counted. If you observe any species of wildlife throughout Boulder County, remember to continue adding to the Boulder County Wildlife Project, too!

We have some awesome prizes available to participants this year, ranging from REI’s Flash 18 Print Backpacks, Lily’s Sweets chocolate bars, Earthhero’s Zero Waste gift boxes, nature photography coffee table books, and more. Make sure you set aside some time to get outside!

For more information about the Boulder-Denver CNC and to learn about events in the area, check out this page and follow us on Facebook. Questions? Contact Melanie Hill at the WILD Foundation, melanie@wild.org.

During winter's long nights, our nocturnal residents are harder than ever to spot. But they leave tell-tale footprints behind in the mud and snow! This month, keep your eyes open for the subtle signs of your strangers in the night, and post them on our iNaturalist project! Even if you can't identify the tracks yourself, someone in the iNaturalist community will be able to help. Consider adding something to your photo for scale - your hand, a coin, a pen - and describe the habitat where you found the track. The morning after a fresh snow fall is the best time to go for a hike, since the tracks are fresh and clean. You will be amazed to see how much activity has occurred!