Horned Guan is endemic to the highlands of western Guatemala and south-eastern Chiapas, Mexico. Knut Eisermann and Claudia Avendaño contributed to the knowledge on the distribution and natural history of Horned Guan in Guatemala.
- Eisermann, K., A. Burge & G. López (2007) Nesting records of Horned Guan (Oreophasis derbianus) on Atitlán volcano, Guatemala. Bulletin of the IUCN / BIRDLIFE / WPA Cracid Specialist Group 23: 13-24. PDF
- Eisermann, K. & C. Avendaño (2018) An update on the inventory, distribution and residency status of bird species in Guatemala. Bulletin British Ornithologists' Club 138: 148-229. PDF