In the mountains, nests in the shrubby undergrowth of decidiously forested river gorges with a partially open canopy and sparse ground cover (Dunn and Garrett 1997, Nicholson 1997) that drain the Blue Ridge plateau (Potter et al. 1980); also along waterways, ravines, and steep hillsides (Simpson 1992). In the coastal plain, breeds in floodplains (Parnell 1977) in 'impenetrable' wet thickets (Potter et al. 1980) with dense cane or broadleaf evergreens (Fussell 1994). Areas are generally shady with muddy soil or standing pools of water. Extensively flooded swamps are not used (Dunn and Garrett 1997). The species is semicolonial in small areas of suitable habitat (Ehrlich et al. 1988), with males having adjacent territories, each less than an acre in size. The nest usually lies on the edge or just outside of the territory (Griscom and Sprunt 1957).

Nest located 1 to 10 feet above the ground in a shrub, palmetto, or vine (Potter et al. 1980). The foundation of the nest may be a cluster of dead leaves on the head of a cane plant or a clump of Spanish moss lying across a cane (Griscom and Sprunt 1957). Forages on or near the ground, turning over leaves and probing into the soil with its bill (Ehrlich et al. 1988). Also forages on the base of tree trunks and in fallen logs, and rarely in slow-moving water (Dunn and Garrett 1997).

NATURE SERVE GLOBAL HABITAT COMMENTS:

Meanley, (1971, p 25), describes the optimum habitat as 'a rich, damp (but not wet) woods with deep shade and moderately dense undergrowth.' These conditions are met in the floodplain and swamp forests of the Atlantic and Gulf Coastal Plains, and in some moist forests of the southern Appalachians. On the coastal plains, this warbler occurs in the shadiest parts of the forest, with dense upper canopy, lower canopy and shrubs, and little herbaceous cover. The shrub stratum is often nearly monospecific stands of giant cane, ARUNDINARIA GIGANTEA (floodplain forest), sweet pepperbush or fetterbush (swamps at the northern end of range such as the Great Dismal Swamp in Virginia, and Pocomoke Swamp in Maryland and Virginia, and headwater swamps of the Atlantic Coastal Plain), or scrub palmetto (bottomlands). In the mountains, moist lower slopes of mountain ravines at elevations to 900 m are preferred, and a shrub layer of rhododendron is most common (Bent 1953, Meanley 1971, Hooper and Hamel 1979). Individuals were found primarily in sawtimber and to a lesser extent in pole stands of second-growth cove forests in the Southern Appalachians (Hooper 1978). Although the warbler is often reported to inhabit canebrakes in the literature, it is clearly not exclusively a cane species; structure of the habitat - both overstory and dense shrub understory canopies characteristic of successional forests - is apparently of primary importance, and a variety of shrubs will do (Graves 1992).

There are few quantified descriptions of habitat. Meanley (1971, p 31), noted that as of 1968 there were still some sections in the Ocmulgee floodplain forest (near Macon, Georgia) 'where canebrakes, nearly uninterrupted, covered 1-sq mile areas.' He recorded densities of cane poles of about 50,000 per ha, averaging five m high, and some reaching to 10 m near Macon, Georgia. In Monkey John Swamp in South Carolina, Meanley recorded 90% canopy coverage ('density'). The scrub palmetto understory averaged about one m in height, with about 20,000 plants per ha.

Eddleman et al. (1980) provide another quantified look at habitat characteristics in southern Illinois in the Shawnee National Forest. Some of their conclusions differ from those of Meanley. Eddleman et al. found that the species composition of overstory varied widely among warbler territories, and concluded that it had little effect on habitat selection. However, a substantial majority of the birds in their study nested in soft-mixed hardwoods (25 of 36). While the majority of singing males in their study were in forest with overstory trees over 20 yr old, the warblers were found in habitats ranging from late successional old fields with dense shrubs and surrounded by mature forest, to late-successional-stage forest. Figures on the frequency of territories falling in each stage were not given. Meanley (1971) noted a few cases where they were found in what he deemed to be marginal habitat (mostly dryer areas). He attributed these cases to areas where the warblers were locally common, and the population 'spilled over' from optimum to marginal habitats. This is a possible explanation for Eddleman et al.'s discovery of this warbler in unlikely habitat such as late-successional old fields.

In the Eddleman et al. study, individuals were never found in habitat with trees less than 7.6 m tall. Canopy coverage was always greater than 55%, and usually greater than 75%. Shrub stems (mostly cane) averaged over 26,000 stems/ha in their study, compared to nearly twice that in a study by Meanley (1966) in Georgia. These Illinois birds were only found in sites where soils were alluvial silts and clays. Male territories were limited to forest tracts at least 350 ha in size, and birds were always found within 200 m of water.

Eddleman et al. (1980) concluded that younger cane stands are needed, that cane needs openings to regenerate and that logging can be used to create openings to manage canebrake habitat. These conclusions have not been corroborated by follow- up studies. And apparently, no further studies characterizing habitat in other locations have been published. Results of timber cuts in warbler habitat in the Shawnee and South Carolina are described under MGMT.REQS.

While most accounts agree that this ground-foraging bird prefers areas with little to no live ground cover, accounts of the midstory of the forest vary. Burger (pers. comm.) reports that they are found in cane stands within forests with good overstory, and no midstory, while Meanley (1971) reported three layers to the forest canopy.