[afterburn 549]

Adult bears are generally immune from predatory attacks from anything other than tigers or another bear. Some bears emerging from hibernation will seek out tigers in order to steal their kills.[29] However, in the Russian Far East brown bears, along with smaller Asiatic black bears constitute 5–8% of the diet of Siberian tigers. In particular, the brown bear's input is estimated to be 1–1.5%.[30] Tiger attacks on bears tend to occur when ungulate populations decrease, and occur mostly in the late autumn/early spring[31]. Large adult bears are generally immune to tiger attacks in summer, but have been killed in their dens in winter.[32].There are also records of bears killing tigers, including fully grown adult males and tigers whose sex and age were not specified [33], either in self defense, or in disputes over kills or for consumption.[34][35]