A controversy arises over the purity of the Indian tiger after DNA samples show Siberian tiger genes.

By Subhadra Menon

Royal Bengal TigerBlue blood with a hint of A scandalous liaison? That is what a strand of hair and a DNA profile has indicated. A team of wildlife researchers has found the DNA samples of two Royal Bengal tigers (Panthera tigris tigris) from Dudhwa National Park in Uttar Pradesh "polluted" by genes of the Siberian tiger.

Surrounded by feline DNA fingerprints, Lalji Singh, deputy director of the Centre for Cellular and Molecular Biology (CCMB), Hyderabad, who led the research team, says the findings are disturbing. "The genetic purity of the Indian tiger in Dudhwa will be lost," he warns, "and we will end up with a mixed-gene pool." The Royal Bengal is small and brilliant coloured -- tawny, golden yellow, with dark stripes -- and its fur sticks close to its body. It has pointed ears and a lean jawline. In comparison, the Siberian tiger -- hardly 200 of which survive in Russia's far eastern corner -- is the biggest of the five living tiger sub-species: the others being the South Chinese (P. tigris amoyensis), Sumatran (P. tigris sumatran) and the Indo-chinese (P. tigris corbett); the Caspian, Javan and Bali tigers are now extinct. The Siberian is a fine cat with rounded ears, a massive jaw, and thick, soft fur.

The CCMB study has busted the myth that Indian tigers are genetically confined to their own pockets. Working on blood and hair samples from 22 tigers of "known wild origin" from all over the country, Singh studied the vital sequences of the DNA that are peculiar to each species. The readings showed around 21 per cent heterozygosity in Indian tigers, which means that the felines drew genetic characteristics from more than one gene pool. Much of the variation arose out of cross-breeding between tigers from the country's 23 tiger reserves. This low level of variation indicates inbreeding, given that the average variation in wild carnivores is 40 per cent. What is more, on analysing 50 to 125-year-old tiger skins from museum specimens, Singh found almost the same level of genetic variation.

The two samples taken from Dudhwa were of tigers suspected to be hybrids. The genetic information obtained certainly related to the Siberian tiger. The big question is: where did the alien genes come from? The two tigers from Dudhwa could be the offspring of Tara, a tigress controversially released into the wilderness by wildlife enthusiast Billy Arjan Singh in the '70s. Questions had been raised in Parliament about Tara's origins and there was, at some point, the admission that she was not of Indian stock.

"Since the 20 other samples showed no Siberian genes, it is possible that the genes came from Tara," says Lalji Singh. He, however, adds that two specimens constituted too small a sample base to conclusively prove that Tara was the source of Siberian genes. "Ideally, all the tigers in the Dudhwa region should be studied before a definitive statement can be made," he says. If not from Tara, who? There are some theories about the influx of foreign genes (see box). While the Himalayas effectively squashes the probability of tigers from India crossing over to China or Russia, it is possible that an Indian tiger mated with a Chinese tiger along the Myanmar tract. The Chinese tiger could, in turn, have inherited genes from a Siberian parent. Theoretically, tigers of unknown lineage which have escaped from zoos and circuses could also be the source of the Siberian genes.

Will the Siberian genes then make the Royal Bengal a pale shadow of its majestic self? "The big cats are characteristically conservative in their breeding habits," says Ravi Chellam, scientist at Dehradun's Wildlife Institute of India. Which is perhaps why the Indian tiger -- anyway restricted to pockets in the tiger reserves -- has tended to breed within its distinctive population. Scientists are worried about inbreeding depression, where highly inbred animals become sterile, are susceptible to infections and lose their vitality. However, Chellam explains that inbreeding isn't a real problem unless the group shrinks to 50 individuals or less.

This strengthens the case for out-breeding, which takes place, say, when a tiger from Corbett National Park in Uttar Pradesh mates with a tigress from the Sunderbans; in other words, when there is an influx of genes from populations other than the one immediately surrounding the animal. The cubs of such a union could show better resistance to diseases or enjoy a robust physique. This means that the Siberian gene could make the Royal Bengal tiger a bigger animal, if a less beautiful one.

Lalji Singh's Siberian gene finding has people worried. "This kind of genetic pollution could affect the purity of the Royal Bengal stock," stresses R.L. Singh, chief wildlife warden of Uttar Pradesh. While there are many who thumb their noses at the argument about retaining the purity of the Indian tiger, it is in keeping with today's thinking. Maintaining the purity of wild gene pools is the current philosophy of conserving species. This is notwithstanding the fact that different species are known to interbreed in the wild. There is, for instance, a new species called the Brown Langur, the product of the mating between the Nilgiri Langur and the Common Langur.

To a lot of experts, genetics lies on the fringe of conservation programmes. "The role of genetics in the endangerment of a species is highly exaggerated," says Ullas Karanth of the Wildlife Conservation Society of the US. He says that the ecological threats faced by vulnerable animals like the tiger are bigger worries. Still, the genetic identification of wild tiger populations is not something that can be ignored. Which is why Lalji Singh thinks he's only just begun an important task. He feels that immediate and extensive studies should be done on the genetic profiles of tigers in all the reserves of India. That, he says, can become the blueprint for action to save these great cats.


Credit to Samkarma Sameer Puri

So, we have a thread about the top predator's behind big cat's and bear's, i think we could also add a thread about the toughest and most dangerous prey hunted by the world's most domiant predator's - also by those from the second row.

2 rules:

- please add only terrestrian or half terrestrian mammals
- only use prey, which is hunted at least by a significant amount of frequency (means, no elephants or rhino's), otherwise the dicussion would be over too fast

I start with the obvious candidate's:



Gaur (Bos Gaurus)
The world's largest and most powerfull bovines. Despite their huge size, they are surprisingly fast and agile.
Adult animals are hunted by Tiger's only, calves are occasionally also taken by leopard's or dhole's. 



Wild Water Buffalo (Bubalus Arnee)
Slightly smaller than Gaur's, but equipped with more devastating horn's with a wide range.
One of the rare'st wild bovine's in present days. Adult specimen also hunted by tiger's only througout their distribution range.



The cape buffalo (Syncerus Caffer)
Africa's so called "black death", responsible for (rumored) hundred's of human death's yearly and feared for its aggresiveness.
Is hunted mostly by lion's, but also spotted hyena's do hunt them occasionally.



American Bison (Bison Bison)
America's biggest mammal, has no reason to hide behind his tropical counterparts.
Subadult's and calves are hunted by wolves and sometimes also by brown bear's, while adult bull's rarely fell victim to predator's.



Walrus (Odobenus Rosmarus)
Living in the northern polar and pacific region's. Protected by a huge amount of fat and blubber + impressive tusks.
Preyed by Polar Bear's.



Wild boar (sus scrofa)
Almost present in every continent. Huge male boar's can reach size's of respective dimensions.
Even if hunted frequently by tiger's and wolve's (and some other's from time to time), there are documented case's, where wild boar's killed their attacker's - even tiger's.

Feel free to add some more if you want and tell your choice and reason about it - a top 3 would be also nice.

 

I made this thread to get information about big dinosaurs that walked on earth. So Lets discuss and debate about them.

Just like modern animal, biggest dinosaurs belong to herbivorous group. In our world Animal like Elephant, Giraffe, Rhino, Hippo are the biggest, heaviest and longest animal and all are herbivorous.

Biggest dinosaurs are sauropods. By far the largest creatures ever to roam the earth, sauropods branched into numerous genera and species over the course of 100 million years, and their remains have been dug up on every continent.
From my sources, The biggest verified dinosaurs is Argentinosaurus. The size of Argentinosaurus has been supported by convincing evidence. In 1986 the remains of this gigantic titanosaur was discovered in Argentina (and hence the name).

According to paleontologists Argentinosaurus could have weight 100 tons and over 120 feet long from head to tail.
Other contender are Amphicoelias fragilis, Bruthathkayosaurus, Futalognkosaurus and Brachiosaurus.

 Amphicoelias fragilis said to be longest and may be heaviest dinosaurs of all time, Source claim that it was 200 feet long and almost 125 tons heavy.
This dinosaur is represented in the fossil record by a single vertebra measuring 5 by 9 feet long, truly enormous proportions that correspond to a sauropod measuring about 200 feet from head to tail and weighing over 125 tons.
But Not everyone is convinced, especially since we no longer have that backbone to examine. So I don't think it should be considered as biggest dinosaurs

Bruthathkayosaurus found in woodland of India is said to weight about 200 tons and 150 feet long. But once again not enough evidence to support it.
Pieces of Bruthathkayosaurus that have been identified so far don't convincingly support to a titanosaur

Futalognkosaurus is also of huge size nearly 100 feet long and 75 tons heavy. Good thing about this dinosaurs is that about 70 percent of skeleton has been recovered which is more than any titanosaur.

There are many more contender in this category and I am sure many of other will emerge in future.

Next we will discuss about Giant theropods (Meat eating). Like Spinosaurus, Tyrannosaurus Rex and Giganotosaurus

Scientist has divided the Mesozoic Era (250-65 million years ago) into 3 periods, viz, Triassic Period (250–200 million years ago), Jurassic Period(200–145 million years ago) and Cretaceous Period(145–65 million years ago).
Dinosaurs first appeared in Middle Triassic period about (230 million year ago). In this thread we will talk about Triassic period.
Will will discuss not only about dinosaurs but also the climate, environment, flora and fauna in that period.

This is a thread dedicated to the unique Leopards that inhabit the rainforests of Africa. Most of you know that there are some speciments from the Rainforest that looks to be extremely large, probably amongst the biggest in the world. And I wanted to make this thread to share the information i got on these Leopards, and hope that others can contribute with good facts.
So post all information you got regarding Leopards from Gabon, Congo and so on. 

So I'm pretty sure that this has never happened, and as far as I'm aware no attempts to do so either have been attempted in captivity. If anyone has any information at all in regards to this question I'd very much appreciate it. Given that they are most closely related to tigers I suppose an attempt could be made or maybe even with clouded leopards, not that I encourage it of course.....

This forum seems moderated well enough to have a debate thread on interspecies fights, so why not make a strict forum on animal fights? Not only will it bring more traffic in the forum, but it will create more chances to learn specific studies and feats of animals that is not very discussed here. Isn't that what this board is all about?

This is a thread where you can post information, pictures and videos of the leopards that inhabit Sabi Sands





 

Post Documentories in regards to the people on the frontline line of conservation that you find Interesting.

Very interesting short doc showing just how hard it truley is to spot a tiger in the dense jungle.

Long but very interesting doc on the History of the Tiger in General.