Last week CBC news reported that surveys of the Bathurst migratory barren-ground caribou herd had dropped from 128,000 in 2006 to 31,900 this year. The herd now has to cross an ice road on its migratory path and there are a number of mines within its traditional range. Caribou are known to be very sensitive to human disturbance.

You can read the original story here: http://www.cbc.ca/canada/north/story/2009/09/24/nwt-bathurst-caribou.html

And for more background see this earlier blog post about mammal migrations: /blog/?p=149