Why Ligers Grow Bigger?
Ligers grow bigger than lions and tigers. Ligers are the biggest of the big cat species. Furthermore; it is not only the weight of the ligers which is bigger but also their body lengths, heights, body structures and organ sizes are also almost twice bigger than lions and tigers. This only happens in ligers that they are being able to grow bigger than the sizes of their parents. No other hybrid big cat is able to grow this much bigger as ligers. But why ligers are bigger especially when they are the offspring of the lions and tigers? What are the possible factors and reasons for their such a huge size? There are a lot of theories, facts and explanations about ligers becoming so much huge and this article tends to extract all the factors contributing to the huge size of the ligers.
The best answer which we have found so far about ligers being able to grow so big is from National Geographic. According to National Geographic which is one of the biggest animal research network in the world; ligers lack growth inhibiting genes which do not put a cap (limit) on their body growth and this is the key reason that they tend to grow bigger and stronger than lions and tigers. In normal case a lion passes on the genes that encourage growth while the lioness put a limit to these genes and that’s why a suitable size of a lion is maintained. On the other hand; tigresses do not have genes which inhibit the growth and male tigers do not have genes that encourage growth. Therefore; when a tigress mates with a lion; the lions’ growth encouraging genes are passed on to ligers without any inhibition cap and as a result; ligers grow bigger than lions and tigers.
However; this theory looks very controversial when we look at the other hybrid big cats which have lionesses as their mothers. First of all how do they know that the tigers’ genes don’t encourage growth? This is generalized on the fact that when a male tiger mates with a lioness a tigon is produced and its size range is almost same as that of lions and tigers. But Jaglions produce another scenario! Jaglions have a male jaguar as their father and lioness as their mother. The sizes of Jaglions are also bigger than that of a jaguar and since lioness promote growth inhibiting genes then why do the Jaglions still able to grow bigger and almost in the same size range as that of the lions and tigers? The theory which generalizes about lionesses’ growth inhibiting genes does not seem to work here and why do the male jaguars have genes that encourage growth in producing the jaglion.
Therefore; these arguments put a doubt about the liger growth theory stated on National Geographic. First of all they fail to explain what the growth encouraging hormones are and why only male lions possess them? Secondly; why Jaguars also have growth encouraging hormones? It looks like this is all based upon some kind of assumption and there is no biological proof behind it because as soon as we start exploring the big cat hybrids, we see results which do not align with the liger theory stating absence of growth inhibiting genes within ligers.
Another key argument which National Geographic failed to account is the ability of the liger to grow faster than all the other big cats. According to the findings of the big cat experts at Myrtle Beach Safari; a liger grows on average one pound per day during the first 4 years of its life. On the other hand; lions and tigers grow at around half a pound per day during the first 4 years of their lives. Therefore; we can conclude that when a crossbreeding takes place in between a male lion and a tigress, the offspring possess genes which have faster growth rate than lions and tigers. But can we associate growth inhibiting genes with it or not? This still remains a question mark.
Summarizing all the above arguments, we can conclude that there is no ultimate theory which proves that why ligers grow bigger and stronger than the other big cats. The theory which states that they lack growth inhibiting genes does not support especially in the case of other hybrids such as Jaglions. If ligers lack growth inhibiting genes then they should grow all their lives but this is not the case because the ligers grow only first 4 to 5 years of their lives just like lions and tigers. Therefore; arguments stating ligers’ bigger growth phenomena still lack solid foundation and more research is required to be carried out in this field.