Geographical distribution of Ruffed grouse   range
BirdLife International. 2016. Bonasa umbellus. The IUCN Red List of Threatened Species 2016: e.T22679500A92816403. https://dx.doi.org/10.2305/IUCN.UK.2016-3.RLTS.T22679500A92816403.en. Downloaded on 27 June 2018.
Cephas