by John Sparks Forty years ago, Sarah Sloane was scratching around for a dissertation topic that would take her to to the Chiricahua Mountains (southeast Arizona), where her husband had already decided to work on his dissertation on forest ecology. A comparative study of three species of wren was the initial idea, but she decided […]
Bushtits: A Lifelong Passion Read More »
iNaturalist is a great app for exploring the biodiversity in your area, and especially shines in natural spaces, like Oaks Bottom. Learn to use it as a plant identifier, or get involved with community science!
Using iNaturalist in Oaks Bottom Read More »
By Ruth Howell While the great blue herons command attention and the cottonwoods stand bare against the winter sky, something quieter and older is having its moment at Oaks Bottom. Look down. Look closely. The moss is awake. Winter is moss season in Portland. When the rains return and temperatures drop, mosses do something remarkable:
The Moss Awakens: Winter’s Hidden Spectacle at Oaks Bottom Read More »
by John Sparks In 1959, the City of Portland acquired most of what is now Oaks Bottom Wildlife Refuge. In the ensuing three decades, the City floated various plans to develop the bottomland, while environmental organizations, including the Audubon Society of Portland (now the Bird Alliance of Oregon), The Nature Conservancy, the Sierra Club, and
The Creation of Oaks Bottom Wildlife Refuge: An Interview With Mike Houck Read More »
by Rosalind Jackson With the year drawing to a close, we’re taking a look back at the work our organization, as well as our larger community, has been doing in service of Oaks Bottom. Join us, as we reflect on some of the highs and lows of the last year. In 2025 we held six
2025 – Year in Review Read More »
by John Sparks Saturday, December 6th witnessed Friends of Oaks Bottom’s last work party of the year. We convened at Tadpole Pond after rain sprinkles ended and patches of blue sky expanded overhead. The actual task was to get 150 red osier dogwood (Cornus sericea) starts in the ground as a first stab at mitigating
Dealing With Dogwood: A Planting at the Bottom Read More »
In September 2025, an invasive beetle no bigger than a sunflower seed was discovered at the David Douglas Aquatic Center in Northeast Portland. For those who love Oaks Bottom Wildlife Refuge, this news marks the beginning of a profound transformation. The emerald ash borer (EAB) has arrived in Portland, and with it comes the near-certain
A Tiny Beetle, A Big Threat: How the Emerald Ash Borer Will Transform Oaks Bottom Read More »
by John Sparks In April 2025, Oregon Health Authority experts tested the waters of Wapato Marsh at Oaks Bottom and found a “concerning” level of microcystins at 191 μg/l (micrograms per liter). (Microcystins are toxins produced by cyanobacteria; the other major cyanotoxin is cylindrospermopsin.) Accordingly, in May, warning signs were posted on the trails at
Harmful Algae Blooms at Oaks Bottom Read More »
Friends of Oaks Bottom held its summer nature walk at the Bottom on Friday, July 11th. The refuge was a lush green oasis with swallows of several species diving and darting over the waters of Wapato Marsh snagging insects. Other summer residents included kingfishers, Canada geese, mallards, gadwalls, and wood ducks. We spotted a couple
Summer Nature Walk – July 2025 Read More »
By Ezra Cohen A stark change has marked the transition from spring to summer in Oaks Bottom this year. The lake is drying up. Mud has crept outward from the edges of the basin, leaving dirtied, rivulets of water in its wake. Visitors to the refuge have noted this change, often worriedly, and theories abound:
What’s with the Water? Read More »
If you’ve ever walked the trails at Oaks Bottom Wildlife Refuge and caught a glimpse of something tiny zipping past — a flash of green, a glint of rose — chances are you’ve crossed paths with one of the refuge’s smallest residents: the Anna’s hummingbird. These birds are not just eye-catching; they’re remarkable in every
The Tiny Architects Among the Trees: Anna’s Hummingbirds at Oaks Bottom Read More »
Article and photos by John Sparks In recent years, 23 species of duck have been observed at Oaks Bottom, including two exotics (Muscovy duck and Mandarin duck). Some ducks, such as red-breasted merganser, cinnamon teal, greater scaup, and common goldeneye, pop up only occasionally. Others are seen with seasonal frequency; these include ring-necked duck, bufflehead,
Get Your Ducks in a Row: The Common Ducks of Oaks Bottom Read More »