The Salish Sea was formed by cycles of glaciation that ended about 10,000 years ago. The lowlands feature rocky soil with river valleys that historically experienced regular flooding, which deposited richer soils along the floodplain. The climate in the western part of Washington trended towards drier, and plant communities in the lowlands were similar to those found east of the Cascades, in what is now shrub-steppe habitat. Our prairies are remnants of this drier climate – the species found here are adapted to seasonal rains, periods of hot, dry weather, and low-intensity fire. Many have deep roots and tough seeds that rely on nutrients released by fire to germinate, if not the heat of the fire itself. The indigenous peoples of the Puget Sound and Willamette Valley (Nisqually, Chehalis, Puyallip, Stillaguamish, Kalapuya, Chinook and many others) recognize the importance of fire for these species and use fire as part of their food cultivation practice, which historically limited the growth of non-fire hardy trees like Douglas fir and replenished soils with a flush of carbon, nitrogen and other macronutrients. Garry or Oregon white oak was one of the dominant trees on these open bunchgrass prairies, mature trees growing with lots of open space between them, also encouraged by indigenous fire practices.

Streaked horned larks, Oregon vesper sparrows, and slender-billed white-breasted nuthatches are all bird subspecies found in the Puget Sound and Willamette Valley region. A subspecies is identified as distinct from the rest of the species by differences in range, behavior, physical characteristics, and genetic differences. One way that subspecies become separate from their “parent” is through geographic isolation: in the case of those found in the Puget Sound and Willamette Valley region, periods of glaciation cut them off from the rest of their kind east of the Cascade mountains. Over time, they developed their own habits, migration routes, and phenology, becoming obligate to the Garry oak-bunchgrass prairie habitat that once occupied the lowlands and foothills.

Post-European settlement, bunchgrass prairies were tilled under for agriculture and grazed, Garry oaks were felled, and cultural fire practices were suppressed as a tool of genocide against the indigenous peoples of the northwest. Invasive turfgrass species were introduced for livestock forage and lawns, and fir trees were allowed to proliferate, partly due to their value as timber, and due to fire suppression. As a result, the subspecies of birds that are unique to the oak-bunchgrass prairie have become imperiled. At Ecostudies, we are contending with centuries of habitat loss and fragmentation, fire suppression, and a colonial mindset of ownership and domination rather than kinship that are directly contributing to steep declines in these unique ecosystems and the subspecies that evolved with them.