One of the most enigmatic woodpeckers in North America, and likely to remain so because of its general rarity and uncertainty about its population dynamic, the Black-backed Woodpecker breeds in boreal forests, from central Alaska and northern Canada, to montane areas of California and New England. Despite its widespread breeding distribution, this species is confined mostly in stands populated by wood-boring insects in coniferous forests. It is an irruptive species that forages opportunistically on outbreaks of bark (e.g., Scolytidae) and especially wood-boring (e.g., Cerambycidae) beetles colonizing recently burned habitats. This restricted diet renders the species vulnerable to local and regional extinction due to fire-suppression programs, salvage logging (post-fire and post-outbreak), and rarefaction of mature/overmature forest stands.
The Black-backed Woodpecker’s sooty black dorsal plumage camouflages it against the bark of the trees that it favors for foraging. Its loud foraging taps, calls, and drumming patterns, however, facilitate detection. Both the Black-backed and its congener the American Three-toed Woodpecker are easily approached, but the Black-backed often challenges an intruder with its Scream-Rattle-Snarl Call, one of the most distinctive and complex calls among Picoides woodpeckers. Three toes instead of four and, in males, a yellow crown patch instead of red, distinguish both the Black-backed and Three-toed woodpeckers from all other woodpeckers.
This species’ dependence on fire landscapes and other large-scale forest disturbances is well known and exemplified by studies across its range: Alaska (Murphy and Lehnhausen 1998), Washington (Latif et al. 2013), Oregon (Cahall and Hayes 2009, Russell et al. 2009, Latif et al. 2013), California (Hanson and North 2008, Saracco et al. 2011, Seavy et al. 2012, Tarbill et al. 2015), Idaho (Saab et al 2004, 2007, 2009, 2011, Dudley and Saab 2007, Dudley et al. 2012, Latif et al. 2013), Alberta (Hoyt and Hannon 2002, Koivula and Schmiegelow 2007), Montana (Hutto and Gallo 2008), Wyoming (Vierling et al. 2008), South Dakota (Bonnot et al. 2008, 2009, Rota et al. 2014a,b), and Québec (Nappi and Drapeau 2010, Nappi and Drapeau 2011). Recent studies revealed the importance of unburned forests for the species (Tremblay et al. 2009, Fogg et al. 2014, Tremblay et al. 2014, Tremblay et al. 2015a,b), and arose questions about significance of beetle outbreaks on species demography (Bonnot et al. 2008, Rota et al. 2014a). Irruptive movements of Black-backed Woodpeckers into southeast Canada and the northeastern United States have been well documented, and demonstrate this species’ remarkable ability to travel long distances (Van Tyne 1926, West and Speirs 1959, Yunick 1985), which seems to be linked with juvenile dispersion (Lowe et al. in prep.).
Recently, a study brings new insights on the species genetics where two populations, Oregon Cascades-California and Black Hills, would be distinct from the boreal population (Pierson et al. 2010). These two populations are isolated, face habitat restriction and were petitioned to be listed under the Endangered Species Act of 1973 (US; Hanson et al. 2012). For the future, studies that should prove especially useful in understanding the Black-backed Woodpecker’s unique relationship to boreal forest disturbance dynamics include (1) dynamics of dispersion and demographic rates, (2) gene flow and genetic structures among populations, (3) wintering ecology, (4) spatial and temporal pattern of pulse-resource interactions on demography, (5) impacts of forest harvesting, and (6) impacts of climate changes.