The liger is a hybrid offspring of a male lion and a female tiger. It is often believed to represent the largest known cat in the world.
Liger, offspring of a male lion and a female tiger. The liger is a zoo-bred hybrid, as is the tigon, which is the result of mating a male tiger with a female lion. The liger and the tigon possess features of both parents, in variable proportions, but are generally larger than either. It is thought that most, if not all, male ligers and tigons are sterile. The females, however, on occasion, may be able to produce young. The terms liger and tigon are portmanteaus of the words lion and tiger.
Ligers tend to be larger and heavier than members of their parent species. Biologists suggest that the liger’s large size, or “growth dysplasia,” results from the absence of certain growth-limiting genes. Female lions mate with several male lions throughout their lives, so the genes of a male lion are adapted to maximize the growth of his offspring, since his offspring may be required to compete with those of other males produced by the same lioness.
The genes of female lions, however, are adapted to cancel or dampen the effects of the growth-maximizing genes of male lions, so lions remain within a given size range. Tigers, on the other hand, have no such competitive mating strategy, and many biologists argue that tigresses do not possess the growth-limiting adaptations of their lioness counterparts.
As a result, the influence of the growth-maximizing adaptations provided by male lions is greater, which allows ligers to become larger than their parents. However, for tigons, growth-limiting genes are found in both male tigers and female lions, so their offspring possess an abundance of these genes, which accounts for their smaller size.
The largest ligers often grow to lengths of more than 3.3 meters (10.8 feet) and weigh more than 400 kg (900 pounds); however, there are reports of some individuals weighing more than 1,000 kg (1 metric ton [about 2,200 pounds]). Tigons, in contrast, tend to be the same size or smaller than their parents, because the growth-limiting genes are carried by both parents.