ROOST TREES USED BY PILEATED WOODPECKERS IN NORTHEASTERN OREGON

We wanted to identify the types of trees and habitat used by pileated woodpeckers (Dryocopus pileatus) for roosting, and to develop management guidelines to provide this habitat. Thus, we located 123 roost trees used by 22 pileated woodpeckers and observed their roosting behavior in northeastern Oregon, 1989-90. In all 443 instances, adult pileated woodpeckers roosted inside a cavity at night. The majority (62%) of the roosts were in grand fir (Abies grandis), both live and dead, that, were extensively decayed by Indian paint fungus (Echinodontium tinctorium). The decay had created a hollow chamber inside the tree that averaged 4.3 m long (SE = 0.22) and 28 cm (0.29) wide where birds roosted. The majority of roosts occurred in old-growth stands of grand fir, with greater-than-or-equal-to 60% canopy closure and little or no logging activity. Trees used for roosting and for nesting differed. Roost trees usually were live grand fir, were smaller in diameter, had more holes, and occurred lower on the slope than did nest trees. Roost habitat should be provided within 243-ha management areas for pileated woodpeckers and should retain old-growth stands of grand fir, large-diameter grand fir infected with Indian paint fungus, and large-diameter dead ponderosa pine in old-growth stands on mid- to upper slopes. Management agencies also should use the formula we developed to determine the number of roost trees to retain within each pileated woodpecker management area.