Restoration Potential: So long as appropriate areas of old growth forest are maintained, the potential for restoration of woodpecker populations is high. Introduction of birds to areas where they have been extirpated, such as Prince Edward Island (Godfrey 1986), may be possible using techniques developed by DeFazio et al. (1987) for red-cockaded woodpeckers. Captive breeding is a possibility, but has not been accomplished, nor is it an acceptable alternative to habitat maintenance. Several woodpeckers have been maintained in captivity, some for several years (Hoyt 1950, Rumsey 1968), thus at least the knowledge is available for short-term maintenance of birds that might be used in translocation efforts.
Preserve Selection and Design Considerations: Preserves should be designed differently for different geographic regions and habitat types. For example, in the eastern and southeastern U.S., every opportunity should be taken to link preserves to corridors of forest habitat along major rivers and streams. In montane areas of the west, preserves would be best along rivers and streams, but also on the windward rather than on the leeward sides of mountains because of the higher humidity (hence greater decay, hence greater food and nest site potential) associated with windward sites.
In various areas, reported as requiring forest patch sizes of at least 20-70 ha, unless other forested areas are nearby (Bushman and Therres 1988). Dispersal distances need to be known and considered when planning any preserve or management area, and data from birds in similar habitats within the region should be used for planning purposes. Dispersal data are scant at present, based on recoveries of banded birds in New York (32 km from site of banding) and Alberta (16 km), and from detailed studies of banded and radio-equipped birds in Oregon in which birds nested from 0.7 to 8.7 km from their natal site (Bull and Jackson 1995).
No estimates have been made of minimum viable population size for this species, nor for that matter have populations been carefully defined.
Management Requirements: Short and Horne (1990) listed five factors upon which conservation of European woodpeckers depends. These are a minimum starting point for the conservation of the pileated. The factors are: 1. Maintenance of wooded areas in which dead and dying trees are allowed to remain. 2. Retention of dead or dying stubs of some live trees. 3. Retention of dying trees in open areas of parkland, golf courses and woodland. 4. Management of wet forests to allow decay of rotting trees (it should be remembered that dying trees are part of the ecosystem, and their integration into new growth as humus is important to natural forest regeneration). 5. Selective cutting rather than clear-cutting of managed forests.
Optimal forest management practices for the mid-Atlantic states include those that maintain a density of around 24 snags per 40 ha; suitable nest sites can be provided by leaving uncut filter strips along streams or by maintaining dense stands where long-continued competition weakens sawtimber trees (Bushman and Therres 1988). Removal of thinning slash or logging debris (foraging substrates) reduces habitat quality (Renken and Wiggers 1989).
The woodpecker was selected as a management indicator of old growth forest ecosystems for some U.S. Forest Service regions. On Pacific Northwest forests, an emphasis has been placed on leaving > 5 standing dead trees (snags) per ha as potential nest and roost sites and on leaving 120 ha patches of older forests (Brown 1985, Bull and Jackson 1995, Thomas et al. 1979). Most of 100 woodpecker management areas were occupied by the species on five National Forest ranger districts in Oregon and Washington (Bull and Jackson 1995).
Mellen et al. (1992) questioned the adequacy of Forest Service management guidelines because home range data were based on density estimates. Based on home range and habitat use data from the Pacific Northwest, Bull and Holthausen (1993) recommended increasing the size of management areas (to 364 ha) and the number of management areas per forest. Composition of management areas should be about 75% in grand fir (ABIES GRANDIS) type, 25% old growth, the remainder mature stands; at least 50% of the stands should have > 60% canopy cover, at least 40% should remain unlogged, and the remainder should be selectively logged to leave mature stands after logging. Because of the importance of downed logs as foraging sites, Bull and Holthausen also recommended leaving > 100 logs (preferably > 38 cm diameter) per ha. To provide for nest and roost sites and foraging, they also recommended leaving > 8 snags per ha with a preference for snags > 51 cm dbh.
See Mitchell (1988) for specifications for the construction and placement of nest boxes.
Management Research Needs: 1. Greater knowledge is needed regarding the relationship between arthropod habitat requirements and those of the woodpecker. Although studies have identified habitat parameters needed by the woodpecker, the nature and significance of phenological variation in key habitat components has not been adequately addressed. For example, what factors influence the longevity of a snag that is a potential cavity or food tree? What is the nature of the progression of decay and invasion by prey of the woodpecker?
2. How is nesting success and fledgling weight/health related to habitat quality? How do nestling development features and phenology found by Hoyt (1944) compare across the range of the species and the range of habitats in which the bird is found?
3. How many feeding trips per day are made to nestlings of various ages? How far do parents travel in habitats of different types to find food for nestlings?
4. To what extent could nest trees be created by killing large trees and then topping them to leave a cross section exposed at the top to encourage fungal decay? [This has been done experimentally in Oregon with explosives (Bull et al. 1981).]
5. Could artificial roost/nest cavities be created following the approach taken for red-cockaded woodpeckers (Copeyon 1990, Allen 1991)?
6. At what age do fledglings become independent of parents? How does this vary geographically, seasonally, or with habitat quality? Does survival and success of young vary with age at independence?
7. What factors influence successful dispersal of young? How far will they normally disperse?
8. Can fledglings be successfully introduced to isolated areas with small or no populations using techniques such as those employed for the red-cockaded woodpecker (DeFazio et al. 1987)?
9. How genetically variable is the species? To what extent is forest fragmentation contributing to genetic fixation within populations?
10. Numerous studies and anecdotal materials indicate that the diet emphasizes CAMPONOTUS ants and beetle larvae, with the seasonal addition of fruit and a wide array of foods when opportunity appears. However, even the most detailed of these studies do not allow good comparisons to be made and do not allow examination of diets of males versus females, adults versus juveniles, or the potential for significant geographic variation. Nor have studies of diet been linked to habitat quality. Further work is needed to clarify dietary needs and variation and relationships of diet quality to habitat quality and home range.
11. Why do pileateds enlarge the cavities of red-cockaded woodpeckers? Answers to date have been speculative and offer little in the way of behavioral observations.
Biological Research Needs: 1. While the incubation period of the species is given as 18 days by several authors (Bendire 1895, Burns 1915, Hoyt 1944, Harris 1982), these authors seem to be quoting one another with little hard data. Kilham (1979) gives the incubation period as 15-16 days. Since the incubation period of the closely related black woodpecker (DRYOCOPUS MARTIUS) is given as 12-14 days (Cramp 1985), further study with better documentation seems to be needed.
2. Why do pileated woodpeckers excavate on utility poles and houses, and how can these actions be deterred?
3. Several species of woodpeckers have been shown to have sex-specific foraging niches. Is this true for pileateds?
4. What is the key species role of the pileated? What other species are dependent on it for nest/roost cavities or for food resources. The excavations of pileated woodpeckers are often used as foraging sites by other species (Jackson, pers. obs.).