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conserved in managed forests, without the need to see if their habitat flexibility is as strong as that of the black woodpecker in Scandinavia. MANAGEMENT RECOMMENDATIONS FOR PILEATED WOODPECKER CONSERVATION IN MANAGED FORESTS My research is applicable to Alberta foothills forests for general habitat ecology, and to central Alberta and British Columbia forests for cavity tree ecology. However, I believe that pileated woodpecker habitat ecology should be similar in forests with similar tree species composition, disturbance regimes, and climate. In particular, I expect that pileated woodpecker habitat ecology would be consistent with my results in western Canadian cordilleran, boreal, and sub-boreal forest regions. The following recommendations include a combination of my results and my own thoughts on what would be appropriate ranges. Forest managers should not interpret these recommendations as absolute numbers that must be achieved. They are more appropriately applied as general guidelines. Conservation of pileated woodpeckers in managed forests should focus on long-term maintenance of large damaged and dead wood structure at both landscape and stand scales. I recommend using definitions of potential cavity trees as living or dead deciduous species and dead coniferous species ≥30 cm dbh and potential foraging substrates as snags, stubs, and defective/decayed living trees ≥20 cm dbh. These include 98% and 82% of used cavity trees and foraging substrates, respectively. I believe it is more important to manage for a larger proportion of used habitat structure than to manage only for habitat structures that are statistically selected. Although pileated woodpeckers used smaller trees as cavity trees, they clearly preferred larger trees, and large deciduous trees have higher levels of stem decay than smaller trees. Living deciduous trees with external decay indicators, especially fungal conks, have the highest potential value. Logs and stumps are also important as foraging substrates in summer, but the focus should be on standing substrates, which are a critical resource in winter. Because pileated woodpecker pairs defend exclusive territories, an appropriate management scale for provision of habitat should approximate the average size of pileated woodpecker territories, about 2,000 ha. Management of numerous 2,000 ha units across forest landscapes is needed to sustain populations. Landscapes could be assessed in a GIS by determining habitat configuration within each cell of a 2,000 ha uniform grid or within 2,000 ha windows placed randomly. Squares or circles would reasonably approximate the shape of pileated woodpecker territories in my study. It is unlikely that pileated woodpeckers would continue to occupy recently logged landscapes unless there is retention of trees and snags in harvest areas and/or a component of stands of forest ≥7 m tall (approximately 30 years old) either interspersed within each 2,000 ha landscape or bordering it. My study did not determine the quantity of stands or substrates needed within a territory area to support a pair of pileated woodpeckers. However, the territories in my study contained about 200–600 potential cavity trees (≥30 cm dbh with stem decay) and 10,000–25,000 potential winter foraging substrates (≥20 cm dbh, dead trees or living trees with damage or decay). These ranges could be used as a conservative guideline for how much to leave standing as a combination of residual stands and structure in recently harvested areas. Converted to an average number of trees/ha, the ranges are 0.1–0.3 potential cavity trees/ha and 5.0–12.5 potential winter foraging substrates/ha. Locations of potential cavity trees and winter foraging substrates could be in stands within the territory and trees or clumps retained in harvested or tended areas. If known, existing cavity tree stands should be the highest priority for maintenance at the landscape scale. I emphasize that it is possible, and I believe likely, that pileated woodpeckers could prosper in forest landscapes with lower quantities of potential cavity trees and foraging substrates than these estimates. I recorded successful reproduction in landscapes with <10% forest. To minimize risk, I recommend a minimum of 5% retention at the stand level in or bordering recently harvested areas of approximately 2,000 ha. Areas protected from harvesting for other purposes should be sufficient to meet pileated woodpecker habitat needs in most situations. At the stand level, maintenance of potential cavity trees and foraging substrates in harvest areas and stand tending programs would help to conserve pileated woodpeckers. Trees containing existing cavities and basal foraging excavations have the highest value because cavity


Pwp 2001 04 rpt phdthesis pileatedwoodpeckerhabitatecologyinabfoothills

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