There is strong regional variation in Rangifer herd size, but many herds currently have unusually low numbers and their winter ranges in particular are smaller than they used to be. There are large population differences among individual herds, and the size of individual herds has varied greatly since 1970. The largest of all herds (Taimyr, Russia) has varied between 400,000 and 1,000,000; the second largest herd (George River, Canada) has varied between 28,000 and 385,000.