Les W. Gyug1, Chris Steeger2, and I. Penny Ohanjanian3
1Okanagan Wildlife Consulting, 3130 Ensign Way, Westbank, B.C. V4T 1T9; e-mail: email@example.com
2Pandion Ecological Research Ltd., 532 Park Street, Nelson, B.C. V1L 2G9; e-mail: csteeger
34481 LD Ranch Road, Kimberley, B.C. V1A 3L4; e-mail: firstname.lastname@example.org
Abstract: Williamson’s Sapsucker sap trees in British Columbia were characterized based on incidental observations of sap trees from 2004 to 2008, and sap tree frequency of occurrence was based on systematic and random tree samples near nests in 2006 and 2007. Douglas-fir was the most common sap tree (85%), but western larch, lodgepole pine, and ponderosa pine
sap trees were also found. The majority of sap trees (75%) were between 23 and 47 cm diameter-at-breast-height (DBH). Sap trees were found up to 460 m from nest trees, but most occurred within 100 m. Douglas-firs 23–52 cm DBH, with injuries to the trunk, and within 60 m of nests were six times more likely to be sap trees than any other class of trees. Overall, the majority of sap trees occurred in classes of trees that have very low frequency of sap trees (<4%) which suggests that sap tree availability is not limiting.
Key words: Williamson’s Sapsucker, Sphyrapicus thyroideus, sap trees, British Columbia
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