An endemic species is one that is restricted in range to a particular habitat or region. In birding parlance the term often refers to a species being found only in one country. There are numerous endemic woodpeckers around the globe, with isolated islands often having endemic species. Here is a male Black-necked Woodpecker Colaptes atricollis race peruvianus, which is endemic to parts of Andean Peru. Taken in the Maranon Valley, Peru, November 2012, Gerard Gorman.
Arizona Woodpecker Picoides arizonae. This is a male, females lack the red hind-crown patch. Note that despite the name, this species also occurs in northern Mexico. Photo taken near Portal, Arizona, USA in July 2014, by Gerard Gorman.
Woodpeckers tend to make simple calls, much simpler in structure than those of, for example, most passerines. Calls are highly functional and are made year round, by both sexes. But the extent to which the different species call varies greatly, some are rather taciturn, others (especially gregarious social species) are often noisy. In this photo a Cardinal Woodpecker Dendropicos fuscescens in Tanzania is in full voice (Gerard Gorman).
Here is an often silent, easily over-looked and seldom photographed woodpecker from Africa: Elliot's Woodpecker Dendropicos elliotii male. Photographed in the Bwindi Impenetrable Forest, Uganda, by Gerard Gorman.
Andean Flicker Colaptes rupicola. A male of thepuna race, which has red on the hindneck and in the malar stripe. This is one of the world's most terrestrial picids. Photo, central Peru, November 2012, Gerard Gorman.