White Tigers: Species Mortality and Conservational Value

In response to inquiries after my previous blog entry, Macrocosmos and Microcosmos, I wanted to write about white tiger breeding and their conversational value.

First a quick history: white tigers are very rarely found in the wild. In about 100 years only 12 wild white tigers have been seen in India but they have long been a source of myth. They instill a sense of beauty and awe but folklore also calls them an omen of death, so while they are idolized by some, they are savagely hunted by others. This was the fate of one tiger, named Mohan, who was captured as a cub in 1951 by a Maharajah and his hunting party. Mohan was caged and was destined to father a significant portion of the world’s captive white tiger population.

Since the dramatic characteristics of white tigers are the result of a rare and recessive gene, all white tigers in zoos now are the descendents of Mohan or a other captive orange tigers whose recessive genes showed up through breeding programs. White tigers now represent a grossly disproportionate part of the captive tiger population compared to the natural world. The natural rarity of these animals and pressure from zoos and collectors to produce more white tigers means that current captive breeding pools go back to only a few closely interbred individuals.

"The white tiger controversy among zoos is a small part ethics and a large part economics. Owners of white tigers say they are popular exhibit animals and increase zoo attendance and revenues as well.”
- Dr. Ron Tilson, Conservation, Director of the Minnesota Zoo and Manager of the Tiger Species Survival Plan

Most genetic defects are recessive and so are masked by normal genes but with persistent inbreeding, genetic problems are amplified and accumulated resulting in disabilities and high mortality rates. Dr. Daniel C. Laughlin (Consultant for Big Cat Rescue) estimates that 80% of white tiger cubs die from birth defects associated with the inbreeding necessary to cause a white coat.

Of those surviving, most have such profound birth defects, such as strabismus (cross eyes), retinal degeneration, cleft palates, scoliosis of the spine, clubbed feet, as immune deficiency, and kidney abnormalities. This means that only a small percentage are suitable for display and are poor performers and so after the great expense and effort spent on breeding them, they cannot all be used for their intended purpose. In addition to the phyical problems associated with these animals there are also mental impairments such as depression and unpredictable behaviour.

The world’s most famous white tigers performed in Siegfried & Roy flamboyant Las Vegas show at The Mirage. The long-running closed its doors when one of the tigers attacked Roy Horn in 2003. The tigers are still housed at The Mirage who continue to use them as a tourist attraction.

“Siegfried & Roy have dedicated their lives to preserving these rare animals [white tigers], and their efforts have helped save them from total extinction.
- The Mirage, Las Vegas website

The Mirage gives the impression that white tigers are a race that needs to be conserved. The public is generally unaware of the strains on the captive tiger population and to use white tigers as a poster child of conservation is an abuse of the public’s faith. Conservation is occurring of a ‘non species’ white tigers survive in the wild but only in extremely small percentage, as long as we preserve a diverse range of the more ordinary orange tiger we will preserve the white tiger.

"The Tiger Species Survival Plan has condemned breeding white tigers … they serve no conservation purpose."
- Dr. Ron Tilson, Conservation, Director of the Minnesota Zoo and Manager of the Tiger Species Survival Plan

Macrocosmos and Microcosmos: white tigers and the humble amoeba

This week pictures were released by Taman Safari Indonesia Animal Hospital & Zoo of two Sumatran tiger cubs and a pair of orangutan babies who have been sharing a home over the last month. All four were orphaned, rescued and are now being housed together at the animal hospital. The snapshots show gentle affection, playful behaviour and even a helpful orangutan feeding a tiger cub.

I am unsure what made the zoo decide to keep these animals together. Perhaps they are experimenting with bonding between species, or may be it was a more logistic matter of space. Regardless, the result is that the four have bonded and there are ethical dilemmas to consider in the near future. What if one of the animals gets aggressive and hurts the other? How will they react to separation if they continue to be as attached to each other as they are now? Holding animals in captivity means severely disrupting their relationship with their natural habitat and social structure. What are our responsibilities as conservationists?

I have long been of two minds about zoos. Like most people, I do not enjoy seeing animals in small cages and cringe when I see large animals display ‘stir crazy’ repetitive behaviour. But the greater good voice in my head says that without zoos we could not create awareness of biodiversity and fund many conservation programs. Of course safari parks are a way to ease the conscience over traditional zoos but despite their growing popularity, they have yet to resolve one of the most striking problems about conservation: a greater value is placed on the conservation of large, ‘sexy’ animals then small, ubiquitous species such as small mammals, amphibians, reptiles, insects, algae or microorganisms.

One example of this slanted perspective on biodiversity is white tigers. These spectacular animals are not a true breed but in fact the result of a rare, recessive genetic anomaly occurring in the more ordinary orange tiger (typically the Bengal Tiger subspecies) . Their fur is white or creamy, they have pink noses, usually blue eyes and black, smoky grey or chocolate-brown stripes or may lack stripes all together.

Until 1951, white tigers were a part of Indian folklore, then a rich Maharajah hunted and captured a white tiger cub and kept it in his palace. This tiger, Mohan, (the Enchanter) is thought to be the only white tiger ever caught in the wild. All white tigers in zoos now are the descendents of Mohan or other captive orange tigers whose recessive genes showed up through breeding programs. The novelty and excitement that such an animal generates means that now while less then 1% of the natural tiger population display the unusual phenotype, a significant number of captive tiger populations are white.

Since wild white tigers are so rare, the current captive breeding pools goes back to only a few individuals and there is so much pressure from zoos and collectors to produce more white tigers, that a host of inbred – related problems have begun to surface including strabismus (cross eyes), retinal degeneration, postural problems, clubbed feet, weakened immune systems and kidney abnormalities.

Zoos cater to the public’s demand of BIG! SEXY! FURRY! and FEROCIOUS! And so they over represent animals such as tigers, elephants, hippos and other macrocosmos. To get across the reality of biodiversity we have to make microcosmos interesting for people. Let’s be honest, does a kid runs up to a tank of water full of floating/swimming algae, amoebas and diatoms and get excited? No. Do children enjoy looking at sketches of insects and peering at them through a commplex dissecting microscope? No. So how do we bring microcosmos interesting? One of the best displays I have seen is at the Royal Tyrell Museum in Drumheller, Alberta. Their Burgess Shale gallery shows colourful large scale models of ‘swimming’ creatures in their marine environment. Visitors walk through the space which is dramatically lit and gives the real sense of being on a sea bed.

Media also plays a vital part. One of my favourite movies is Claude Nuridsany and Marie Pérennou's 1996 documentary Microcosmos. 15 years of research, 2 years of equipment design, and 3 years of shooting went into making this amazing venture into the hidden world of a French meadow. Especially memorable are a gross scene of slugs kissing and a humorous excerpt of a toiling dung beetle.

Large screens, high resolution graphics and even CGI help bring attention to small organisms but I don’t know if amoebas will ever have much of a ‘cool factor’. Anyway, next time I am at the zoo, I am going to spend a little extra time appreciating the small things.