From Purple Martins to River Otters
- Jul 7
- 3 min read
By Amy Porter, Director of Conservation
Published in Wolf Tracks vol. 43, no. I
Spring 2026
Spring is a season of renewal, and this year, we have some exciting wildlife updates to share. Thanks to generous grant funding from Greater Good Charities, Wolf Haven was able to build habitat for a threatened native bird on our prairie: the purple martin (Progne subis)! In partnership with Kelly McAllister – Coordinator of the 2026 Washington State Purple Martin Census Project – and our colleagues at Center for Natural Lands Management, we built and installed 12 purple martin nest boxes to create critical nesting opportunities for the species.
The purple martin is the largest swallow in North America and a true aerial acrobat, feeding almost entirely on flying insects caught in mid-flight. Highly social, purple martins typically nest in colonies, with multiple pairs breeding close together during the spring and summer. They are also long distance migrants who travel thousands of miles each year between spring North American breeding grounds and wintering areas in South America, primarily Brazil. Their survival depends on healthy habitat across this entire migratory pathway.
Sanders Freed from Center for Natural Lands Management (CNLM) installing some of the purple martin nest boxes on Wolf Haven's prairie
While purple martins remain relatively common in parts of eastern North America, western populations have declined significantly. In Washington, they are designated a “Species of Greatest Conservation Need” under the State Wildlife Action Plan. Historically, western purple martins nested in natural tree cavities and standing snags near open landscapes such as prairies, wetlands, and shorelines. Today, many of those nesting structures have disappeared due to logging, fire suppression, and development. Introduced species like European starlings (Sturnus vulgaris) also compete aggressively for remaining cavities. Properly designed and monitored nest boxes help address these challenges by providing safe nesting spaces that exclude starlings.
The trees selected for Wolf Haven’s purple martin boxes are Douglas firs – a species that poses a long-term challenge to prairie restoration if left unmanaged. Across the South Puget Sound, Douglas fir encroachment is one of the primary threats to native prairie ecosystems. Without active management, these trees gradually overtake open grasslands and replace the diverse prairie habitat many species depend on.
The three trees chosen for our project were already identified as candidates for removal as part of ongoing restoration work. Rather than removing them entirely, we made a deliberate decision to transform them into standing snags that could support diverse wildlife. Using a lift, one tree was topped and the other two were girdled – a process that removes a ring of bark and cambium to stop nutrient flow, allowing the tree to die standing and gradually become valuable habitat.
Over time, these snags are expected to benefit not only purple martins, but also woodpeckers, bats, tree frogs, and other cavity-dependent species. Wolf Haven similarly maintains nest boxes for western bluebirds (Siala Mexicana), another native species that relies on cavities in open landscapes. Unlike purple martin boxes, which are installed high on snags and designed for colonial nesting, western bluebird boxes are smaller, spaced farther apart, and mounted lower to accommodate their territorial nesting behavior.
Some additional exciting news: our trail cameras recently captured a video of river otters walking along the oak woodland path, marking the first sighting at Wolf Haven in about a decade! This rare observation highlights the growing use of our restored habitats by native wildlife, and underscores the broader success of our efforts to create a thriving, connected ecosystem where a full suite of native critters can flourish.
