Conserving Purple Martins in the Willamette Valley

The purple martin (Progne subis) is the largest swallow in North America. The species was once common in the Willamette Valley seventy years ago, but populations have declined dramatically. Possible contributing factors in the disappearance of purple martins include the loss of snags with changing forestry practices and competition for nest cavities from European starlings.

A small colony of perhaps 12-20 purple martins persists in Oregon State University’s Dunn Forest.  The colony is remarkable because it is one of the last places in North America where martins continue to nest in tree cavities.  Except for a handful of sites on the West Coast, martins have shifted entirely to nesting in man-made structures.  Unfortunately, the Dunn forest martins have to compete with starlings for nest sites.

OWI is seeking reports from persons sighting purple martins with colored leg bands.  Please note the band color and on which leg it is attached.  Contact: Dave Vesely

In 2011, OWI erected two racks of artificial gourds with starling-resistant entrances in an effort to conserve the Dunn Forest colony. More than 80 juvenile martins have fledged from these gourds from 2011 to 2014.  Dr. Joan Hagar of the US Geological Survey has been banding the fledglings to make it possible to identify these birds in the future. In 2016, 45 nestlings were banded in the Dunn Forest gourds, and two adults’ bands were resighted. One of those birds was a two-year old male, banded as a nestling at Ridgefield National Wildlife Refuge in Washington.

By preserving the Dunn Forest martin colony, we hope to sustain a source population from which individuals will emigrate deeper into Oregon Coast Range forests and further away from starlings.  Because starlings will continue to inhabit the Willamette Valley in the foreseeable future, starling-resistant housing will be necessary for purple martin recovery. The U.S. Fish and Wildlife Service refuges and Army Corp of Engineers are already providing hundreds of nest boxes for martins and OWI is looking for opportunities to establish gourd racks on private lands in the mid-Willamette Valley.

Download the OWI 2013 Purple Martin Report (838 Kb).

Sponsored by:  Oregon Wildlife Heritage Foundation