With no explanation, label text_A→text_B with either "not_related" or "related".
text_A: The Gray wolf is threatened by tigers.
text_B: The gray wolf or grey wolf -LRB- Canis lupus -RRB- , also known as the timber wolf or western wolf , is a canine native to the wilderness and remote areas of Eurasia and North America .. canine. Canis. Eurasia. Eurasia. North America. North America. It is the largest extant member of its family , with males averaging 43 - and females 36 - .. extant. Neontology. Like the red wolf , it is distinguished from other Canis species by its larger size and less pointed features , particularly on the ears and muzzle .. red wolf. red wolf. Its winter fur is long and bushy and predominantly a mottled gray in color , although nearly pure white , red , and brown to black also occur .. , 37 subspecies of C. lupus are recognised by MSW3 .. subspecies. subspecies. MSW3. MSW3. The gray wolf is the second most specialised member of the genus Canis , after the Ethiopian wolf , as demonstrated by its morphological adaptations to hunting large prey , its more gregarious nature , and its highly advanced expressive behavior .. specialised. Generalist and specialist species. genus. genus. Ethiopian wolf. Ethiopian wolf. morphological. Morphology ( biology ). It is nonetheless closely related enough to smaller Canis species , such as the eastern wolf , coyote , and golden jackal to produce fertile hybrids .. eastern wolf. eastern wolf. coyote. coyote. golden jackal. golden jackal. hybrids. Canid hybrid. It is the only species of Canis to have a range encompassing both the Old and New Worlds , and originated in Eurasia during the Pleistocene , colonizing North America on at least three separate occasions during the Rancholabrean .. Pleistocene. Pleistocene. Eurasia. Eurasia. North America. North America. Old. Old World. Rancholabrean. Rancholabrean. It is a social animal , travelling in nuclear families consisting of a mated pair , accompanied by the pair 's adult offspring .. social animal. social animal. nuclear families. nuclear family. mated pair. mated pair. The gray wolf is typically an apex predator throughout its range , with only humans and tigers posing a serious threat to it .. apex predator. apex predator. It feeds primarily on large ungulates , though it also eats smaller animals , livestock , carrion , and garbage .. The gray wolf is one of the world 's best-known and most-researched animals , with probably more books written about it than any other wildlife species .. It has a long history of association with humans , having been despised and hunted in most pastoral communities because of its attacks on livestock , while conversely being respected in some agrarian and hunter-gatherer societies .. pastoral. Pastoralism. agrarian. Agrarian society. hunter-gatherer. hunter-gatherer. Although the fear of wolves is pervasive in many human societies , the majority of recorded attacks on people have been attributed to animals suffering from rabies .. human. human. rabies. rabies. Non-rabid wolves have attacked and killed people , mainly children , but this is rare , as wolves are relatively few , live away from people , and have developed a fear of humans from hunters and shepherds .
related.