 As of March 2010, there were an estimated 35,000 free-ranging dogs living within Moscow's city limits, or approximately one dog for every 300 people, and about 32 per square km (84 per square mile).According to Andrei Poyarkov of the A.N.Severtsov Institute of Ecology and Evolution, a biologist and wolf expert who has studied Moscow's dogs for over 30 years, the quantity of food available to them keeps the total population of homeless dogs steady at between 35,000 and 50,000.