Capitol Hill, Seattle | Seastock, Canva

by Joshua Morris, Seattle Audubon Urban Conservation Manager and
Erin Fried, Capitol Hill EcoDistrict Deputy Director

Even in the most intensely urbanized parts of Seattle, wildness waits to surprise us. Peregrine Falcons dive from the sides of skyscrapers in chase of pigeons. A six-story-tall Giant Sequoia towers above traffic near the Westlake Center. Amanita mushrooms sprout in fairy tale colors along the sidewalks of Capitol Hill. Despite the hazards and stresses of urban environments, “life finds a way.”

And good thing, too. Plants, birds, bees, and other wild things are important members of our community. They are essential for our health, well-being, and resilience. They help manage stormwater, control pests, and regulate city temperatures. They bring joy and beauty close to our homes. And they extend a line of connection to nature that many humans have been losing hold of in recent decades.

Urban planners, leaders, and residents are increasingly recognizing the importance of integrating nature into our cities. Seattle Audubon, the Capitol Hill EcoDistrict, and the Seattle Bird Conservation Partnership are here to help. We have collaborated to develop a guide to improving habitat values and human access to green space in urban Seattle.

This work arose from two observations:

  • First, that public park space is limited in Capitol Hill, First Hill, and the Central District. These are among the most densely populated neighborhoods of the city. While they are served by many parks, per capita park area is low. In the Broadway neighborhood of Capitol Hill, for example, public parks provide approximately 94 square feet of open space per resident. This is four times lower than the city average and six times lower than the World Health Organization’s ideal recommendation that cities should provide about 540 square feet of open space per person.
  • Second, we observed that 11th Avenue East, which runs north-south through Capitol Hill, strings together serveral large and culturally important parks and open spaces in the area, including Volunteer Park, Cal Anderson Park, and the Seattle University Campus.

Given this limited open space, improving access and connectivity between parks can help people and wildlife take better advantage of all the space available. So how can we improve access and connectivity for people and wildlife between open spaces along 11th Avenue?

That was the primary question we sought to answer throughout our project. While some of our analyses focus on the Capitol Hill area, the strategies we outline and resources we’ve developed can be useful in other neighborhoods, too.

Peregrine Falcon | Will Sooter | Audubon Photography Awards

What have we developed?

We drafted a comprehensive guide, called Connecting Urban Nature, which outlines strategies for enhancing habitat, reducing urban hazards, and improving human access to green space. It is intended to provide guidence to residents, businesses, and others, to enhance habitat. The strategies include improving wayfinding between parks and incorporating public art and amenities, like places to sit or find shelter from rain, in the right-of-way. We stress the importance of protecting and maintaining the vegetation we already have and provide tips on how to add new wildlife-supporting plants. We encourage converting lawns and other plants that form monocultures with more diverse plantings. We also recommend reducing dangers to wildlife from outdoor free-roaming cats, reflective glass, pesticides, and pollution.

We also compiled a list of plant species that support wildlife and people, including plants that would be appropriate for small urban food gardens. We associated each entry in the plant list with information that can help people select species that will work given their personal needs and constraints. Say, for instance, that I’m planning to build a rain garden in a planting strip in the right-of-way. I can use the plant list to identify species that are suitable for rain gardens and that have a maximum width at less than ten feet. Or, if I want to start a balcony garden, I can search for plants that will do well in containers.

Finally, we mapped all of the planting strips in our project area and assessed them for soil depth, percent available planting space, presence of native species, sun/shade exposure, presence of overhead utilities, and more. We also analyzed the percent tree canopy cover in the project area, so we are able to identify planting strips that have room for new vegetation, that are in areas of low canopy, and that are not obstructed by overhead utilities, to help us prioritize habitat enhancement work.

What are the goals of this guide?

  1. To improve human access to and movement between green spaces along the Urban Biodiversity Corridor. 
  2. To increase the wildlife-supporting capacity of the Urban Biodiversity Corridor. 
  3. To reduce urban hazards to wildlife within the Urban Biodiversity Corridor. 
  4. To engage people in conservation efforts right where they live.  
  5. To connect people to nature and wildlife in their own neighborhoods.

Map of the 11th Ave E Urban Biodiversity Corridor. The corridor extends nearly two miles and connects large open space areas at Volunteer Park, Cal Anderson Park, and Seattle University, and smaller areas at Lowell Elementary, Broadway Hill Park, and Thomas Street Gardens.

Who is the guide for?

If you are interested in promoting urban biodiversity and improving access to green space in the Seattle area, this guide is for you. The strategies we outline are intended to be useful for a wide range of individuals, including renters, homeowners, businesses, property managers, and others. The resources and ideas may be useful to many urban areas around Puget Sound.

What is the guide’s specific geographic focus?

The geographic focus area for this guide is an envisioned “urban biodiversity corridor” extending from Volunteer Park to Seattle University in the Capitol Hill, First Hill, and Central District neighborhoods of Seattle.

The corridor is centered along 11th Ave East and generally extends one block on either side. The area contains relatively large patches of habitat and open space at Volunteer Park, Cal Anderson Park, and Seattle University, and contains smaller pockets of green and open space at Lowell Elementary, Broadway Hill Park, and Thomas Street Gardens. In total, the corridor contains 71 acres of publicly accessible open space.



What is the corridor area like?

There’s a lot of steel and concrete.

The neighborhoods containing the project area are, on average, more hardscaped than the city as a whole. Steel, concrete, and other impervious surfaces cover about 60% of the Broadway neighborhood, 73% of First Hill, and 69% of Yesler Terrace. By comparison, the citywide average is about 52% (all percentages +/- 12%; source: National Land Cover Database 2016).

The map on the right shows land cover across Seattle, with an inset view of the project area. The darkest red represents high intensity development.

Given the amount of imperviousness, the spaces that remain uncovered by concrete, asphalt, or other development are precious. They are also likely to diminish in area with new development.

Data from the National Land Cover Database

Canopy cover is not evenly distributed.

Canopy cover in the project area tends to be highest in the north. It thins out approaching the Pike/Pine area, which is the most intensely developed portion of the corridor. To improve habitat values here, we will have to work with building managers and businesses to think about container and rooftop gardens, and to make sure planting strips are fully utilized.

Data from 2016 Tree Canopy Cover LIDAR survey.

Life is finding a way.

Maintaining the ability for people to have direct wildlife and nature experiences right where they live is an important goal of the project. Despite the intense development, limited open space, and dense human population, the corridor area still buzzes, blooms, squawks, and squeaks. People have submitted nearly 1,000 observations of nature in the corridor area, representing close to 350 plant, animal, and fungi species, including more than 100 bird species. 

How can we prioritize habitat enhancements?

Underutilized planting strips are a significant community asset that we can transform into habitat. We found a total of three acres of planting strips in the project area. For context, that is more than four times larger than all the P-patches in the three surrounding neighborhoods. More than a quarter of the area of those planting strips have more than fifty percent available planting space.

With our data, we’re able to hone in on planting strips that meet certain criteria to help us prioritize work. For example, we can prioritize planting strips in low canopy areas of the corridor that have 50% or more available planting space and that are not obstructed by overhead utilities. These sites, for example, might be able to support more trees, which can provide more habitat for birds.


 Map of planting strips and canopy cover with an inset view of the south Capitol Hill section, the lowest canopy area of the corridor.

Example of a planting strip (the area between the sidewalk and street) that is being underutilized in terms of plants and habitat.


Example of a planting strip (zoomed in) in a low-canopy area with more than 50% available planting space that is not obstructed by overhead utilities.

What’s next?

The materials we have developed are out for stakeholder review. We expect to publish the guide in late April. We are also working with our partners to turn the materials into a user-friendly website.

Get involved and learn more

Sign up to be the first to know when we’ve released the guide!
Document the corridor’s biodiversity!

Explore our video archives for more information on pollinators, gardening, birds, and more!

About Josh Morris
Seattle Audubon Urban Conservation Manager

Josh’s work focuses on reducing urban hazards to birds, protecting and enhancing urban habitat, and engaging communities in conservation right in their own neighborhoods. He has been involved in leading Capitol Hill Connections, a collaborative project to restrict pesticide use, engage the community in stewardship, and develop a vegetation plan for birds and pollinators.

About Erin Fried
Capitol Hill EcoDistrict Deputy Director

Erin joined the Capitol Hill EcoDistrict after holding posts in several nonprofit organizations and NGOs that focused on community-based solutions for issues related to immigration, education, post-conflict rebuilding, and the environment. Before working with the EcoDistrict and Community Roots Housing, Erin spent five years serving as the Executive Director of Old Growth Northwest, a volunteer arts organization that provided creative writing opportunities to underrepresented groups. She also trained as a restorative justice facilitator with the Seattle Restorative Justice Initiative. Erin holds a BA in Creative Writing from Carnegie Mellon University, as well as an MA in International Affairs from the Fletcher School and an MA in Urban and Environmental Policy and Planning from Tufts University.


Other articles in this issue of Earthcare Northwest

bird imprint on window

Patio Pals: The Birds and the Bees

While full-scale gardening allows for a large, varied planting palette that birds love, container gardening on a balcony or patio can also provide habitat. Jose Gonzales, a local garden professional and plant expert, walks us through how to get the most out of a small space container garden that encourages birds and other natural pollinators to thrive.

bird imprint on window

Tim-ber? … Not So Fast: The Important Role of Dead and Dying Trees

Trees are essential for birds, even when the tree is dead or dying. We hear from Stuart Niven, a professional arborist, about how snags and woody debris can remain in your yard safely, and provide excellent habitat and food resources for birds.

bird imprint on window

Take the Backyard Habitat Quiz

How does your outdoor space measure up? Have you minimized threats to birds? Are you offering food, water, and shelter options? Discover some obvious and subtle ways you can create a wildlife haven in your own backyard.