Herons of the Salish Sea
The Pacific Great Blue Heron in Olympia is a unique non-migratory subspecies, Ardea herodias fannini, found only in the Salish Sea that stretches from Prince William Sound to Puget Sound. As far as we know, the herons in Olympia represent the southernmost colony of the fannini subspecies. According to testimony from Elizabeth Roderick of the Black Hills Audubon Society, in 1976 there were ten nesting colonies of fannini in Thurston County. At last counting, in 2009, there were only five. Two of the nearest colonies at Mud Bay and Eld Inlet are both gone. In 2006, the last comprehensive survey of fannini in the Salish Sea, there were only ~9000 individuals left. Let me be clear on this point. That means there were only ~9000 fannini left in the entire world. We do not have an accurate account for 2014, but various sources have testified that the overall population of faninni is declining even further.
Great Blue Herons are a sentinel of the biological health of the Puget Sound coastal forest and shorelines. Herons are particularly sensitive to human development, human disturbance and noise. They rely on healthy eelgrass beds, and are threatened by impacts on their feeding grounds, including water acidification, water temperature changes, toxic chemicals, erosion and invasive species. River estuaries in particular are important year-round habitat for faninni, providing abundant year-round prey as well as seasonal foraging of anadromous fish species.
Visit Nancy Partlow's blog post for more details about breeding habits and excellent photos.
Already we've witnessed how development can impact their health. In early 2009, a road intended to be the driveway for the proposed townhomes was logged, exposing the forest canopy and subjecting the West Bay colony to predation from the Bald Eagle. From 2009 to 2013, no chicks survived the end of the summer. Left alone for six years, several chicks successfully fledged in the summer of 2014. The trials of the West Bay heron colony are not over. It is estimated that a mere 30% of fledged herons will survive their first year. More glaringly, the pressures of development have returned.
The Olympia Coalition for Ecosystems Preservation was established to preserve, through advocacy and organization, the vanishing ecosystems of the Great Blue Heron and related species in our increasingly crowded urban setting. We recognize that the Great Blue Herons in Olympia are an integral part of a larger ecosystem that includes the West Bay Woods, Schneider Creek and the nearby shoreline, including the Deschutes River Estuary.
Map of the Salish Sea & Surrounding Basin, Stefan Freelan, WWU, 2009
Known heron colonies in 2006