Characteristics of nest cavities and nest trees of the Red-breasted Sapsucker in coastal montane forests

From May through July 1997 and 1998, I quantified nest tree and cavity characteristics of 32 Red-breasted Sapsucker (Sphyrapicus ruber) nests in the high-elevation coastal forests of northern Vancouver Island, British Columbia. Nests were located in western white pine (Pinus monticola), hemlock (Tsuga sp.), and Douglas-fir (Pseudotsuga menziesii) snags. Nest trees were significantly taller and had a greater DBH chan random snags. Nest height was positively correlated with tree height. All nests were in dead trees. The orientation of nest cavity entrances did not differ from random orientations. When choosing nest sites, Red-breasted Sapsuckers are likely balancing predation risk (decreasing at higher nest heights) and adequate nest space and insulation (greater with increasing diameter at lower nest heights).