Tigers, The World’s Biggest Cat


There’s much more to these fabulous big cats than looks, but first off, who’s up for some gorgeous tiger images and videos?

Scientific name(s):

Panthera tigris

Most of us know three kinds, only two of which are recognized subspecies:

  • Bengal tigers, Panthera tigris tigris, which inhabit the Indian subcontinent

    Excuse me, Royal Bengal tigers. (Image: Pulikken, CC BY-SA 2.0)

  • White tigers, which are still P. t. tigris. They’re not albinos but have inherited a mutation that people encouraged with excessive inbreeding. This led to health problems, but some experts report that, with care, white tigers can be bred and maintained just as well as their naturally orange relatives.

    Jack Fiallos, CC BY 2.0

  • Siberian (a/k/a Amur) tigers, P. t. altaica, found in eastern Eurasia

    Shown here practicing for the swim to Sakhalin Island when it grows up. Tigers are perfectly capable of handling ocean currents to reach offshore islands. (Image: Mathias Appel, public domain)

    All tigers are good swimmers, but it doesn’t always come naturally. If you happen to have some around the house, a little encouragement might be needed:



Other traditional tiger subspecies, per O’Brien and Johnson (2005), are:

  • Sumatran, P. t. sondaica, the world’s smallest tiger:


  • Malayan, P. t. jacksoni (Note: This conservation-oriented video contains a couple images of poached tigers):


  • Indochinese, P. t. corbetti:


  • Caspian (considered extinct for decades, but see Culver et al.: they may be living on in the Amur tiger)
  • Javan (extinct)
  • Bali (extinct)
  • South China, P. t. amoyensis, extinct in the wild:



I teared up when the South China captive stared at the camera towards the end of that video. But we can’t just open the door and let her out.

Overall, that was lots of tiger images and videos! And here’s the point.

We’ve all heard of Bengal tigers, Siberian tigers, and so forth, but did you notice how hard it is to tell many of those cats apart?

The subspecies differences among them are mostly genetic. This has led to a controversy in scientific circles.

Some taxonomists think there should be just two official subspecies: one for mainland Asia tigers and the other for those, living and extinct, of Sumatra, Java, and Bali. (Kitchener et al., 2017)

This proposal has triggered much debate. While it could help conservation efforts by easing the restrictions on how to go about restoring the wild population, it does overlook very real genetic distinctions that some zoologists have found between subspecies.

Lineage:

Big cats (Panthera)

Data:

Tigers generally get the nod when it comes to size, but let’s not forget that this is the highly adaptable family Felidae. There are always exceptions.

Individuals in the Russian Far East, like the one shown above, along with some Bengal tigers on the Indian subcontinent, are world-record holders. However, many tigers in the tropics are smaller than lions.

These averaged data are from the Cat Specialist Group website unless otherwise mentioned (so are the lion data provided for comparison).

Sumatran tiger, showing off his ruff. (Image: Tambako The Jaguar, CC BY-ND 2.0)
  • Weight: 165 to 716 pounds. (Lions: 243 to 600 pounds. To give them their due, lions don’t inhabit the Russian Far East, home to today’s tiger heavyweights.)
  • Height at shoulder: 2.3 to 4 feet. (Wikipedia)
  • Body length: 59 to 91 inches. (Lions: 54 to 98 inches.)
  • Tail length: 35 to 43 inches. (Lions: 24 to 39 inches.)
  • Coat: For some reason, this enormous, rusty red to yellowish-orange cat, covered with dramatic dark stripes and having brilliant white fur on its face and underparts, does not stand out when it wishes to pass unseen. Each tiger has a unique pattern of stripes, varying in number, shape, and direction. The tail has dark rings and a black tip. Males, especially on Sumatra, have a prominent ruff (not a mane), and all northern tigers develop a fairly shaggy winter coat that can be long enough to hide their ears! (Heptner and Sludskii)
  • Vocals: Sonogram studies show that tigers do some parts of what we call a roar but not the full sequence that lions perform. (Kitchener et al., 2010)

    Tigers make other noises, too. They cannot purr, but they have other means for close-range chats.



    Note the white spot on the back of the cubs’ ear. Many wild cats have these. Biologists speculate that it is somehow useful in signalling — certainly it’s obvious when the little cub shows submission to the tigress!


  • Average litter size: 1 to 5, typically (per Ewer) 2 to 3.
  • Average life span: 12 to 15 years.

Features unique to this cat:

  • Some Amur and Bengal tigers are the largest members of today’s cat family

  • Stripes! The tabby pattern is a whole ‘nother genetic thing. Why did tigers evolve stripes? No one really knows. Some writers suggest that they help the cat blend in with tall grass, but as Allen et al. point out, tigers are forest dwellers. And all other cats that do specialize in grassy environments lack such striping.

  • The longest fangs in the modern cat family. (Heske)

    However, that doesn’t make Panthera tigris a descendant of sabercats.

    James St. John, CC BY 2.0

    Believe it or not, there never was a “saber-toothed tiger” — all members of today’s cat family have conical fangs.

    DNA testing shows that Smilodon (shown on the right in this diagram) and other flat-fanged sabercats belonged to a different and now extinct subgroup in Felidae.


  • Possibly the shortest developmental branch of any member of the cat family. Tiger fossils may be 2 million years old, but genetic testing shows that today’s striped wonders only go back some 70,000 to 100,000 years. It seems that something nearly wiped out the world’s tigers at that point. (Cho et al.; Culver et al.) Some experts, like Williams et al., think the Toba supereruption, roughly 74,000 years ago, did it; others, including Haslam and Petraglia, disagree, saying the matter needs more research.

  • The most popular animal in the world, according to a 2004 Animal Planet online poll, narrowly winning over dogs.

Where found in the wild:

Light yellow is their former range; green is where tigers are today. (Sanderson et al., via Wikimedia, CC BY 2.5)

From Siberia to the tropics, but most of the world’s 3,000 to 4,000 wild tigers live in small, scattered groups.

India has the most tigers (2,226 in 2014), but there are also many people there, and the tiger habitat therefore is fragmented. That’s a problem because these big cats need a lot of room.

Russia may have the world’s largest population of tigers in an unbroken land tract (the Russian Far East, where relatively few people live in a few cities and peripheral farmlands). (Miquelle et al.)

The only known reproducing tiger populations are in Bangladesh, Bhutan, India, Indonesia, Malaysia, Nepal, Russia, and Thailand, though there may also be some in China and Myanmar. (Cat Specialist Group)

Closest cat-family relatives:

Molecular studies have shown that tigers and snow leopards are so closely related that they could either have their own group or, as is currently the situation, be classified as big cats (Panthera) along with the lion, leopard, and jaguar. (Kitchener et al., 2017)

How tigers hunt and live:

Any way they want to.

Tigers are born wrestlers, rather than pursuit predators. They’ve got the muscle and body mass to take down even water buffalo and Asian elephants, though they prefer prey that’s about their own size.

Tigers are usually active from sunset to sunrise. They’ll occasionally move around during the day, but that’s typically their resting time. During very hot weather, they’ll hang out in water to stay cool.

While tigers do take small prey like hares and anything else, they need larger animals over the long term. The Cat Specialist Group reports that these cats evolved to hunt and kill large hoofed herbivores like deer and wild pigs.

One tiger needs around 50 to 60 of these prey animals per year.

The tiger generally leads a solitary existence, but multiple cats have been seen feeding at a kill, some of them unrelated. And occasionally several tigers will gather together and hang out for a while even when it’s not breeding season.

No one understands what is going on in these get-togethers, but it might be similar to the sociability that domestic cats sometimes show. (Ewer; Turner and Antón)

Tigers even seem to learn from each other.

During the 1980s, per Turner and Antón, a Bengal tiger in Ranthambore Park named Genghis developed a new technique to attack deer. He waited until they were in the water and then rushed in, distracting them with the splashes.

Such a hunting method had never been described in over two centuries of tiger observations. And after his success, other Ranthambore tigers began using the technique!

How tigers reproduce:


“Mom!” “Mom?” “Are we there yet?” “When’s feeding time?” “Mom!? Hobbes pushed me in and now I’m alllll weeettttt!” “MOM!”
(Mathias Appel, public domain)


Like all cats, males base their territory around females, while the females are more concerned about having enough food resources to support themselves as well as nourish their cubs.

Breeding seasons vary by region. The cubs weigh 2 to 4 pounds at birth. Some are born with their eyes open, others take up to two weeks to develop vision.

Mom will nurse the cubs for about three months, but she begins taking them with her after just two months. It takes a long time to train these hunters, though, and they won’t be ready for life on their own until they’re 1-1/2 to 2 years old.



It takes time to hone a tiger cub’s hunting skills after weaning. Meanwhile, Mom has to catch enough food for her whole family. What many cats probably do is leave the cubs at home during a serious hunt, so they won’t scare off prey, and then later on, bring them along on a sort of “tutorial walkthrough.” Perhaps that’s what’s going on here.


Interactions with people:

Of course tigers are popular at zoos and on safaris, and the number of videos and images in this post — not to mention our reactions to those — is testimony to the close link many of us feel towards these beautiful cats, but there’s a dark side, too.

And not only on our part: poaching, persecution, abuse, and unintended consequences like the genetic defects inbreeding caused in white tigers or agriculture and urban expansion crowding tigers out of their natural environment.

The tigers are big enough to get some of their own back.

Man-eaters are out there in a few places. In and around Nepal’s Chitwan National Park, for example, 37 tigers killed 88 people between 1978 and 2006; there were 32 more deaths and 22 injuries between 2007 and 2014. (Dhungana et al.)

Tigers killed about 40 people in the Sundarbans between 2000 and 2010 (Goodrich et al.) — mostly honey collectors, fishermen, and wood gatherers. In Sumatra there were an estimated 8 deaths per year between 1978 and 1997. (Das)



The “tiger crossed with a cat” that she’s excited about is just the on-site representative of the Felis lineage — Chaus, the jungle cat, southern Asia’s most common small wild kitty. It fills a different predator niche and so can coexist with tigers in the same ecosystem.


Do you want to get off the boat and wade into the Sundarban forest? Okay, but don’t watch this video if you find the sight of bees disturbing!



It’s not easy to protect both human beings and a rare predator.

Fossil relatives:

The oldest known tiger fossils, from Java and, possibly, northern China, are about 2 million years old. The cat from China — Panthera paleosinensis — may actually have been ancestral to tigers. (Christiansen; Werdelin et al., 2010)

Red-listed?

Yes, as Endangered.

Today, tigers are going through another bottleneck because of excessive killing and habitat loss during the last few centuries, as well as today’s illegal hunting for pelts and use in traditional Asian medicine, prey depletion, continuing habitat degradation, and conflict with humans.

In 2010, the St. Petersburg Declaration set a goal of stabilizing this decline and doubling the number of wild tigers out there to at least 6,000 by 2022 — the next Year of the Tiger.

In other good news, the Integrated Tiger Habitat Conservation Programme was also extended for another five years.

Sharing the natural world for our mutual benefit still presents many challenges, though, for both tigers and humanity.


Featured image: Ondrej Prosicky, Shutterstock


Sources:

Allen, W. L.; Cuthill, I. C.; Scott-Samuel, N. E.; and Baddeley, R. 2011. Why the leopard got its spots: relating pattern development to ecology in felids. Proceedings of the Royal Society B. 278:1373-1380.

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Cho, Y. S.; Hu, L.; Hou, H.; Lee, H.; and others. 2013. The tiger genome and comparative analysis with lions and snow leopard genomes. Nature Communications. 4:24-33.

Christiansen, P. 2008. Phylogeny of the great cats (Felidae: Pantherinae), and the influence of fossil taxa and missing characters. Cladistics, 24(6): 977-992.

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Dhungana, R.; Savini, T.; Karki, J. B.; Dhakal, M.; and others. 2018. Living with tigers Panthera tigris: patterns, correlates, and contexts of human–tiger conflict in Chitwan National Park, Nepal. Oryx, 52(1): 55-65.

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Edited June 21, 2019



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