Mean diameter (dbh) of primary excavator nest trees or snags as a function of bird length (bill to tail length) in inland (○) and coastal forests (□) of the Pacific Northwest. Regression lines for inland forests are shown; there were no significant regressions for coastal forests. Bird lengths from [234]. Data of [8, 11, 53–55, 57, 61–64, 68–70, 72, 74, 77, 79, 80, 82, 83, 86, 87, 91–94, 96–99, 103, 118, 162, 164–172, 188, 199, 235–251].