New book documents 400-plus species in web of ‘Hidden Life’ at Aspen Center for Environmental Studies

New book from ACES chronicles effort to catalog all living things at Hallam Lake Nature Preserve

Adam McCurdy
From 'The Hidden Life All Around Us

The new book “The Hidden Life All Around Us” details the findings of a “bioblitz” on the 25-acre wetlands at Hallam Lake Nature Preserve that the Aspen Center for Environmental Studies (ACES) calls home. The blitz and the book documented more than 400 species in Aspen’s beloved backyard. In this excerpt, ACES forest and climate director Adam McCurdy takes us inside the process of figuring out what, exactly, lives here.


A small tract of wetland with a five-acre lake in the heart of Aspen, Hallam Lake Nature Preserve means different things to the many life forms that spend time here.

For massive trees, such as cottonwoods, blue spruce, and balsam poplars, it is a place they have watched over for hundreds of years. For insects like ants, beetles, and midges, it is a vast world larger than they or their offspring will ever be able to explore.

For these tiny creatures, it is all they will ever know, and they are utterly dependent on it for their survival. For the occasional passersby like elk, bears, mountain lions, hawks, or eagles, Hallam Lake is a temporary refuge, a respite from the ever-increasing development on all sides that fragments their habitat. It is a feeding area where fish are still plentiful and mule deer grow fat in the summer. For visitors from farther afield, migrants such as Wilson’s phalaropes, yellow warblers, or tree swallows, Hallam Lake may be one stop of many on their thousands-of-miles journeys. But just like the perfect campsite or bed and breakfast, it is a stop where they can rejuvenate, feed, and prepare for the rest of their journey.

How does one determine which species exist in a particular place?

At ACES, we took into consideration multiple factors. First, we needed to establish the boundaries. Geographically, this is easy. There are lines on a map that show where the preserve begins and ends. The more difficult question was deciding which species to count. One teaspoon of soil has more microbes than there are people on Earth. To make the problem tractable, we decided to count only macroscopic organisms.

Next was the question of time. While some organisms, such as trees, are a constant presence, others, like migratory birds, may spend less than a single day at Hallam Lake.

Eventually, we decided to do what is known as a bioblitz, which meant that we would spend three days finding and identifying as many species as possible. While three days seems like a short period of time (it is), substantial work was conducted before and after—there were many days preparing for the event and then identifying specimens in the lab after the bioblitz was completed.

To conduct the bioblitz of Hallam Lake, ACES partnered with the Colorado Natural Heritage Program (CNHP). The organization’s mission is to “facilitate conservation of Colorado’s biodiversity.” With a staff of seasoned zoologists, botanists, and wetlands ecologists, CNHP was a natural partner for the project.

Over the course of three days in June 2019, CNHP scientists and interns along with ACES staff members combed over the preserve. Starting at sunrise and staying out well into the night, the team worked tirelessly to find and identify as many species as possible. Each day began with a zoology team visiting live-trap lines to see which small mammals had stopped by for a bite to eat and found themselves spending the night.

Additionally, the team members checked wildlife cameras for evidence of the larger preserve residents. Throughout, they kept their eyes on the trees and their ears on alert in search of songbirds. As the sun rose and the days grew warmer, the botany teams would begin methodically exploring the preserve’s wetlands, meadows, and forests, careful to ensure that no plant was overlooked. Entomology teams spent the days turning over rocks, dragging nets, and kicking up sediment in streams.

After dinner, the zoology team would head back out to reset small mammal traps and ensure that acoustic bat monitors were in place. At the end of the three days, we had identified 324 species. Combined with ACES’s other observations of migrant birds and wildlife that did not make themselves seen during the bioblitz, we identified 427 species that call Hallam Lake home.

During those three days, did we find and identify every species at Hallam Lake? Of course not. One thing we can say with complete confidence is that there are more species out there. Insects that had yet to hatch, plants still preparing to emerge, and wildlife that did not wander by a camera or live trap.

We view this effort as a starting point. Over the coming years, we will continue adding to our master list of species, which is reproduced in the new book “The Hidden Life Around Us.” Ten years from now we will repeat the full bioblitz to see what may have changed.

No one knows what Hallam Lake will look like in fifty years. What we can say with confidence is that the species that make up this incredible ecosystem are in more danger today than they have been at any other time in their history. And it is not a single ecosystem that is at risk, it is every ecosystem on Earth. Unlike any of the other great extinctions in Earth’s history, there now exist conscious beings. We humans can choose whether or not we continue losing biodiversity. If we as educators, conservationists, and advocates are successful, in fifty years people will look at the work contained in this book and see it as a testament to what humanity was able to achieve—the preservation of hundreds of species whose continued existence had been in question. If we fail, this work will serve as a record of what was lost, a cautionary tale of wealth squandered.

Adam McCurdy is forest and climate director at Aspen Center for Environmental Studies.


‘The Hidden Life All Around Us’

By Various Authors, Aspen Center for Environmental Studies

304 pages, $55

Tra Publishing, 2020

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