The NYS Breeding Bird Atlas from 2005 shows these birds all over the state and increasing steadily since 1975. They had declined in the northeast severely by 1914 because of the clearing of land for farming. The use of dead trees for firewood by subsistence farmers may have sealed their fates. But the regrowth of trees on marginal farmland and the actual changing of behavior to be tamer have caused the happy increase. Now the birds sometimes use smaller trees in suburban settings, even visiting bird feeders for suet and probably seeds. (We have never had one here so I'm not sure, but hairy woodpeckers stand awkwardly on the tin roof and eat sunflower hearts on occasion.)
The Stokes Nature Guide to Bird Behavior, Volume III, has a wonderful chapter on this Beginning- Birders' Delight. It describes seven visual and auditory behaviors, many of which are similar to other woodpeckers' communication signals, but in this bird they are writ big. Their calls ring loudly through the forest, their resonant drumming (a territorial "song" to them) is lower-pitched, two to three seconds long and getting softer at the end, with drums usually about 50 seconds apart and four to seven times in a row. (But who's counting? -- The Stokes!) The different calls are usually to keep a pair in contact while they are feeding in the forest, to keep rivals at bay or to warn of danger. Or in the case of young, to demand to be fed.
Stokes books always have a nice chart of a bird's behavior throughout the year. Pileated courtship time is the whole month of April and nest building is the last half of April 15 to 70 feet up in a tree. Breeding is all of May, June and July with the young fledging in three or four weeks. The first time out of the nest they may fly 100 yards, no practice necessary! The four or so young continue being fed, by regurgitation, at least partially for three months.
No wonder they need big territories!