Science in the Parks: The Cascades Butterfly Project


March 15, 2022

By Karen Povey, WNPF Board of Directors

Photos courtesy of the National Park Service

As days get longer and winter’s chill begins to wane, many of us are experiencing the anticipation of getting boots back on the trails in our parks’ high country. If you’re among those who delight in wandering summer wildflower meadows, you might want to consider joining the team of community scientists who hike to support research at Mount Rainier and North Cascades National Parks.

One of the most accessible volunteer science programs is the Cascades Butterfly Project, established by the National Park Service in 2011 as a long-term monitoring study of subalpine butterflies and the flowering plants they depend on.

Silvery Blue butterfly

Butterflies: Indicators of Climate Change

Because butterflies have such close relationships with the host plants that sustain caterpillars and provide nectar to nourish adults, they are excellent indicators of environmental impacts caused by a changing climate.

In a 2021 WNPF Virtual Field Trip, North Cascades National Park Ecologist Dr. Regina Rochefort explained why subalpine meadows – and the butterflies that glide among them – are particularly vulnerable to a warming climate. Typically, this habitat is characterized by long winters with deep snowpack and short, mild summers. The slowly melting snow favors meadow plants, keeping brush and trees from establishing and providing moisture to sustain flowers that spring up quickly when the ground warms.

Tiger Swallowtail, by Karen Povey

But, if predictions by climate scientists prove correct, by 2050 average temperatures in the Pacific Northwest will climb by six degrees, creating a future of lower snowpacks and longer, drier growing seasons that make meadows vulnerable to encroachment by trees and brush. These changes have already become apparent in some areas.

A comparison of historic and modern photos clearly shows bushes replacing meadow plants along paths at Paradise

Counting Butterflies and Blooms

Cascade Butterfly Project scientists want to learn if the changing landscape will also transform the dynamics of butterfly populations. The study’s first step has been to create an inventory of the types of butterflies currently winging through the meadows to form a baseline for judging future changes.

A team of volunteers, funded as a priority project through your donations to Washington’s National Park Fund, conduct summer surveys on trails at ten locations in North Cascades and Mount Rainier National Parks and in adjacent National Forests. They record butterfly species and numbers and document the timing of plant flowering. It’s crucial that butterflies emerge as their host plants offer new, succulent leaves for caterpillars and high energy nectar for egg-laying adults.

Data collected over time will document if this synchrony is disrupted by environmental changes. Of the 155 species of butterflies in Washington, 57 have been documented in the study so far.

Butterfly survey sites

If you’d like to hit the trail for science this summer, visit the Cascade Butterflies Project volunteer page for information on getting involved. The need is especially great for surveyors in North Cascades National Park.

Stunningly beautiful, yet so delicate, butterflies are a fitting symbol of the fragility of nature. Our National Park Services scientists are tasked with stewarding our parks’ precious living resources, a mission made more difficult in the face of an uncertain future. Washington’s National Park Fund is honored to have made a long-term investment in working together to protect the plants and animals we love, now and forever.

Learn More & Give Back

If you’re more of an armchair appreciator of the park’s subalpine meadows, you can support the work of butterfly volunteers through a donation to the project through WNPF.

Support Park Projects

Donations make all the difference. Learn more about our donors’ impact on the Cascades Butterfly Project: