Ongoing human development of their habitat has caused populations of woodland caribou to disappear from their original southern range. In particular, caribou were extirpated in many areas of eastern North America in the beginning of the 20th century. Woodland caribou were designated as threatened in 2002. Environment Canada reported in 2011 that there were approximately 34,000 boreal woodland caribou in 51 ranges remaining in Canada (Environment Canada, 2011b). Professor Marco Musiani of the University of Calgary said in a statement that "The woodland caribou is already an endangered species in southern Canada and the United States... warming of the planet means the disappearance of their critical habitat in these regions. Caribou need undisturbed lichen-rich environments and these types of habitats are disappearing."