The liger, is a hybrid cross between a male panthera leo (lion), and a female panthera tigris (Tiger) and is denoted scientifically as panthera leo x panthera tigris. A liger resembles a giant lion with diffused stripes. They are the largest cats in the world, although the Siberian Tiger is the largest pure breed. Like tigers, ligers enjoy swimming. The offspring of a male tiger and a female lion is called a tigon. Under exceptional circumstances it has been known for a tiger to be forced into ranges inhabited by the Asian lion. Reports have been made of tigresses mating with lions in the wild and producing offspring known as ligers. This would have referred to the Gir Forest in India where the ranges of Asiatic Lions and Bengal Tigers overlap. This combination of species in the wild however is considered improbable.
Ligers grow much larger than lions and even larger than the largest tigers, which can weigh in excess of 976 lb (560 kg).
Imprinted genes may be a factor contributing to liger size. These are genes that may or may not be expressed depending on the parent they are inherited from, and that occasionally play a role in issues of hybrid growth. For example, in some mice species crosses, genes that are expressed only when maternally inherited cause the young to grow larger than is typical for either parent species. This growth is not seen in the paternal species, as such genes are normally “counteracted” by genes inherited from the female of the appropriate species.
Another possible hypothesis is that the growth dysplasia results from the interaction between lion genes and tiger womb environment. The tiger produces a hormone that sets the fetal liger on a pattern of growth that does not end throughout its life. The hormonal hypothesis is that the cause of the male liger’s growth is its sterility. Essentially, the male liger remains in the pre-pubertal growth phase. This is not upheld by behavioral evidence – despite being sterile, many male ligers become sexually mature and mate with females. Male ligers also have the same levels of testosterone on average as an adult male lion. In addition, female ligers also attain great size. They weigh approximately 700 lb (320 kg) and reach 10 feet (3.05 m) long on average, but are often fertile.
Ligers are not sterile, and they can reproduce. The fertility of hybrid big cat females is well documented across a number of different hybrids.
Ligers have a tiger-like striping pattern on a lion-like tawny background. In addition they may inherit rosettes from the lion parent (lion cubs are rosetted and some adults retain faint markings). These markings may be black, dark brown or sandy. The background color may be correspondingly tawny, sandy or golden. In common with tigers, their under parts are pale. The actual pattern and color depends on which subspecies the parents were and on the way in which the genes interact in the offspring.