Campephilus principalis formerly occurred at low densities throughout the south-east USA (nominate principalis) and Cuba (race bairdii). Sixty years after the last confirmed North American record in north-eastern Louisiana in 1944, the species was reported to have been rediscovered in 2004 in the Big Woods region of eastern Arkansas3. Evidence for the rediscovery comes in the form of seven sightings, a short poor-quality video, over 100 sound recordings indicative of this species from automatic recording stations, and a number of additional 'possible encounters'3,6,7,8,11. The sound and video recordings have been analysed in detail. However, some consider that this evidence is not yet conclusive8,9,10,12, and intensive searches are currently underway that hope to provide unequivocal documentation of the species's continued existence. There were also unconfirmed reports by researchers working in forests along the Choctawhatchee river in Florida reporting 14 sightings and 41 acoustic encounters heard during 2005-2006 and further sightings and calls in the 2006-2007 field season, but again incontrovertible evidence is still required14. However a search in the coastal mangrove forests and inland hammock forests of south Florida in 2009 failed to find any sign of the species17. Between the last confirmed sightings in 1944 and the 2004 records discussed above there were a further 20 credible unconfirmed reports from within its historic range15. The species may well survive in Cuba, although searches have not found any new records subsequent to those of the late 1980s4. The best hope lies in the Alejandro de Humboldt National Park, in which only a small proportion of the potential habitat has been searched. Calls potentially of this species were heard in 1998 in the Sierra Maestra in south-east Cuba1,2, an area from which there had been no historical records and at an elevation higher than the known altitudinal range of the species4. Follow-up searches in the area found poor habitat and no indications of presence of the species5. A recent statistical analysis of physical evidence and independent expert opinion, as part of a study into the burden of proof required for controversial sightings of possibly extinct species, supported the view that this species is very likely extinct21. Any remnant population in either the USA or Cuba is likely to be tiny.