Following a decrease of
ungulate populations from 1944 to 1959, more than 32 cases[
quantify] of Amur tigers attacking both
brown and
Asian black bears were recorded in the
Russian Far East, and hair of
bears were found in several tiger scat samples. Tigers attack Asian black bears less often than brown bears, as latter live in more open habitat and are not able to climb trees. In the same time period, four cases of brown bears killing female and young tigers were reported, both in disputes over prey and in self-defense. Tigers can tackle bears larger than themselves, using an ambushing tactic and jumping onto the bear from an overhead position, grabbing it by the chin with one fore paw and by the throat with the other, and then killing it with a bite in the
spinal column.[
citation needed] Tigers mainly feed on the bear's fat deposits, such as the back,
hams, and
groin.
[10]
Amur tigers regularly prey on young bears and sub-adult brown bears. Reports of preying on fully grown small female adult Ussuri brown bears by a big male tiger are common as well.
[17][34] Predation by tigers on denned brown bears was not detected during a study carried between 1993 and 2002.
[36] Ussuri brown bears, along with the smaller Asian black bears constitute 2.1% of the Siberian tiger's annual diet,
[37] of which 1.4% are brown bears.
[37][38]Certain tigers have been reported to imitate the calls of Asian black bears to attract them.
[39]
Bears are said by a source to be generally afraid of tigers, and changed their path after coming across tiger trails;
[10][
not in citation given] however, this is disputed. In the winters of 1970–1973, Yudakov and Nikolaev recorded two cases of bears showing no fear of tigers and another case of a brown bear changing path upon crossing tiger tracks.
[40] Other researchers have observed bears following tiger tracks to scavenge tiger kills and to potentially prey on tigers.
[10][37] Despite the threat of predation, some brown bears actually benefit from the presence of tigers by appropriating tiger kills that the bears may not be able to successfully hunt themselves.
[37] Brown bears generally prefer to contest the much smaller female tigers.
[41] During
telemetry research in the
Sikhote-Alin protected area, 44 direct confrontations between bears and tigers were observed, in which bears in general were killed in 22 cases, and tigers in 12 cases.
[42] There are reports of brown bears specifically targeting
Amur leopards and tigers to abstract their prey. In the Sikhote-Alin reserve, 35% of tiger kills were stolen by bears, with tigers either departing entirely or leaving part of the kill for the bear.
[43] Some studies show that bears frequently track down tigers to usurp their kills, with occasional fatal outcomes for the tiger. A report from 1973 describes twelve known cases of brown bears killing tigers, including adult males; in all cases the tigers were subsequently eaten by the bears.
[44][45]
