by Playfuls Staff |
17th January 2007
Yes, it is possible to have larger carnivores than tigers or lions and here is the irrefutable proof that will convince you all.[more]
In a recent article that balances the size of land carnivores with their feeding capabilities, Dr. Chris Carbone and colleagues from the Institute of Zoology, Zoological Society of London have shown that being bigger is not necessarily better. On the contrary, had large carnivores grown even larger, they would surely go extinct.
The explanation comes from the fact that carnivorous land mammals have an upper size limit of 1,100 kilograms. Above this, the costs of living outweigh the benefits of bringing down large prey.
Carnivores are some of the widest ranging terrestrial mammals for their size, and this affects their energy intake and needs. This difference is also played out in the different hunting strategies of small and large carnivores. Smaller species less than 15-20 kg in weight specialize on very small vertebrates and invertebrates, which weigh a small fraction of their own weight, whereas larger species ( >15-20 kg ) specialize on large vertebrate prey near their own mass.
“Carnivores fall into two dietary groups based on the energetic requirements of their feeding strategies: small-bodied species, which feed mostly on prey smaller than themselves, and large-bodied species, which prefer prey around their own size. While carnivores around the size of a lynx or larger can obtain higher net energy intake by switching to relatively large prey, the difficulty of catching and subduing these animals means that a large-prey specialist would expend twice as much energy as a small-prey specialist of equivalent body size. Analyzing the balance between energy intake and expenditure across a range of species, we predict that mammalian carnivores should have a maximum body mass of one ton.”
But an exception is possible though: the one and only animal few have heard about before. It is called Liger, and it is a bizarre and rare combination of a tiger female and a lion male. Check out this
video to convince yourself!
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, but unlike lions, ligers enjoy swimming.
Ligers grow much larger than lions and even larger than the largest tigers, which can weigh in excess of 437 kg (976 lb). The largest non-obese Liger, known as Hercules is said to weigh over 544kg (1200 lb), well over twice the size of a male lion. Hercules was also featured in Maxim magazine article in 2005, when he was only 3 years old and already weighed 408 kg (900 lb) at the time. The liger is the largest animal in the cat family. feline family Felidae.
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 behavioural evidence - despite being sterile, many male ligers become sexually mature and mate with females. Male ligers also have the same levels of testosterone ng/dl on average as an adult male lion. In addition, female ligers also attain great size, weighing approximately 700 lb (320 kg) and reaching 10 feet (3.05 m) long on average, but are often fertile.
Ligers are not sterile, and they can reproduce. If a liger were to reproduce with a tiger, it would be called a ti-liger, and if it were to reproduce with a lion, it would be call a li-liger. The fertility of hybrid big cat females is well-documented across a number of different hybrids.
(exerpts of this article taken from
wikipedia)
