The Snag’s the Limit: Habitat Suitability Modeling for the Western Purple Martin in a Managed Forest Landscape

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The western purple martin is a species of conservation concern throughout the Pacific Northwest. 

To breed, purple martins need moderately decayed snags with nest cavities located away from closed-canopy forest in large open areas. Availability of breeding habitat is believed to be a major limiting factor for western purple martins, but information on their current distribution and selection of nesting habitat is deficient. Oregon State University and USGS researchers studied habitat characteristics surrounding nest snags occupied by purple martins in both privately owned and BLM land in western Oregon. Modeling efforts suggested suitable habitat was rare within the study region because snags were scarce on private industrial forest lands, and large disturbed patches were uncommon on federal lands. Authors suggest a disturbance regime characterized by infrequent but major stand-replacing events, such as fire or timber harvest, is likely the key to maintaining breeding habitat for purple martins in upland forests in western Oregon.  


Sherman, L., Hagar, J.C., 2020, The snag’s the limit- Habitat suitability modeling for the western purple martin in a managed forest landscape: Forest Ecology and Management, v. 480, p. 118689,


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Date published: November 13, 2017
Status: Active

Habitat Mapping and Modeling

Accurately quantifying and mapping wildlife habitat is critical to investigations of species distribution and habitat relationships, and can greatly facilitate management of forests for multiple resources. However acquiring field-based, empirical data is often costly and labor intensive. Modeling provides an alternative technique for describing and mapping habitat, but the usefulness of models...

Contacts: Joan C Hagar