Responses of Cavity-Nesting Birds to Stand-Replacement Fire and Salvage Logging in Ponderosa Pine/Douglas-Fir Forests

Saab, Victoria A. ; Dudley, Jonathan G. 1998. Responses of cavity-nesting birds to stand-replacement fire and salvage logging in ponderosa pine1Dougla.s-fir forests of southwestern Idaho. Res. Pap. RMRS-RP-11. Ogden, UT: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station. 17 p. In spring 1994, the Intermountain Research Station (now Rocky Mountain Research Station), Boise National Forest, and Region 4 of the Forest Service initiated long-term studies on bird responses to different fire conditions in ponderosa pine1Douglas-fir forests of southwestern Idaho. The first phase of the project is to evaluate effects of high-intensity wildfire on cavity-nesting birds and their associated habitats. During springlsummer 1994-1 996 we monitored 695 nests of nine cavity-nesting bird species (including three Forest Service Sensitive Species: Black-backed, White-headed, and Lewis' woodpeckers) and measured vegetation at nest sites and at 90 randomly located sites. The burned forests used for study areas were created in 1992 and 1994 by primarily highC mtensity wildfire, thus most standing trees were snags. Nests and vegetation were monitored in three treatments: standard-cut salvage logged, wildlifeprescription salvage logged, and unlogged controls. Tree densities for small diameter trees (>23 cm to 553 cm [>9" to <20"] diameter breast height [dbh]) in the unlogged units averaged 81 snags per ha (33 per acre) and for larger trees (>53 cm dbh [>20H]) averaged 17 snags per ha (7 per acre). In salvage-logged units about 50% of the trees were harvested, tree densities for small trees averaged 43 snags per ha (1 7 per acre) and for large trees averaged 5 snags per ha (2 per acre). Lewis' Woodpecker was the most abundant (208 nests) and successful cavity nester on the 2-4 year-old burns, while Black-backed and White-headed woodpeckers were rare (23 nests). Lewis' Woodpecker and American Kestrel experienced the highest nesting success in the salvagelogged units, whereas Northern Flicker and Hairy Woodpecker were most successful in the unlogged units. All bird species selected nest sites with higher tree densities than that measured at random sites, and cavity nesters as a group selected clumps of snags rather than snags that were retained in uniform, evenly-spaced distributions. Among bird species, Black-backed Woodpeckers used nest sites with the highest tree densities, while Lewis' Woodpeckers selected relatively open nest sites. Cavity-nesters as a group selected larger diameter and more heavily decayed snags 'than that expected based on availability of such snags. Snags with the highest probability (>85%) of being classified as nest trees were characterized by heavy decay and broken tops that pre-dated the wildfire. We discuss management implications of stand-replacement fire and post-fire salvage logging for cavity-nesting birds. Future plans are outlined, including bird and plant responses to different fire conditions (standreplacement fire, fire suppression, and prescribed fire). The intent of this work is to provide information on the action and no action alternatives to the Forest Health Initiative.