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Wednesday, March 11, 2009

RICHARD FREEMAN: Giant Crocodiles - the supreme predator

Humans are habitual exaggerators. If we can make something bigger, fiercer, faster, more cunning, or more dangerous to man, then we will. We can see this simply by looking at the cinema. Films like Jaws, Anaconda, Alligator, Grizzly and Piranha all turn animals into monsters hell bent on destruction. The creatures of these films seem to exist for no other reason than to eat humans in industrial quantities. Of course exaggerating one’s encounters with wild beasts is an ego boost and makes for a good story, thus legends are born.

But is this true with crocodiles? Certainly some are man-eaters. Certainly some reach enormous sizes. But the question is just how big? Perhaps, in the case of crocodiles it’s just as well that “the ones that got away” did get away.

The record for the biggest reliably measured crocodile is something few can agree on. Some say that it was a 20.3 ft (6.2 m) shot in the Fly River, Papua New Guinea. Others disagree. Some say it was an 8.64 m (28 foot, 4 inch) male shot on the MacArthur Bank of the Norman River, Queensland, Australia in 1957 by Mrs. Kris Pawloski. The mammoth body was too big to move but was photographed, although, sadly, the photograph was lost in 1968. However, Mr. Ron Pawloski was a recognised expert on crocodiles and carefully measured the specimen. He was astounded at its size (having previously measured 10,287 specimens) and having found none to be larger than 5.5m (18 feet).

Dr Graham Webb, crocodile expert and owner of Crocodylus Park in Australia believes Ron’s story. Dr Webb says…”I spent three days talking with Ron and everything else he told me about crocodiles turned out to be very precise indeed. I can’t imagine him fabricating something like this.”

This giant was never weighed because of the impossibility of moving its immense carcass, but conservative estimates put it at a weight of two tons. Other estimates have produced a figure of three tons or more!

Another infamous giant was witnessed in the 1950s by rubber plantation owner James Montgomery. Montgomery’s plantation was near the Segama River in North Borneo. He claims to have shot twenty specimens between 6 and 8 metres in length (20-26 feet) to ensure the safety of workers who washed their laundry at the river.

One particular crocodile dwarfed even these. The local Seluka tribe believed that it was "The Father of the Devil" and threw silver coins into the water to appease it, bringing to mind the dragon hordes of legend.

Investigating, Montgomery found the beast in question hauled out on to a sandbank. The crocodile filled the whole bank and had the end of its tail in the water. Wisely deciding to leave the monster well alone Montgomery retreated. Returning later he found that the sand bank on which the creature had been basking was 9 metres (30 feet) across indicating that the creature must have been in excess of ten metres (33 feet) in length.

Borneo is giant crocodile world HQ with many stories of vast reptiles emanating from it. Back in the mid 1800s British explorer Spencer St. John wrote of such giants in his book Life in the Forest of the Far East.

“The Linggar River is famous for it’s alligators (crocodiles) which are both large and fierce. Alligators sometimes attain to a very large size. I have never measured one above seventeen feet six inches, but I saw a well known animal, the terror of the Siol branch of the Sarawak (River), that must have been at least twenty four or twenty five feet long.”

In 1956 the District Officer of Simanggang, who had the wonderful name of Abang Haji Husaini bin Datuk Haji Abdul Rashid, formed a crocodile hunting club with other government officers. Crocodile attacks had become commonplace along the Lupar in the 50s and the club was intended to curb the menace. In six months ten crocodiles were shot. The largest was fired upon near Pasir Tekalong. After being shot it dived. Three days later its body emerged. It was twenty-four feet long.

The great naturalist Charles Gould, who wrote the cryptozoological book “Mythical Monsters”(some 70 years before the term cryptozoology was coined) was well aware of giant crocodiles. A friend of his, Mr. Dennys - a resident of Singapore - told him of a 9 metre (30 foot) crocodile that haunted a tidal creek that ran through the city in the 1880s. Another colleague, Mr. Gregory - the Surveyor General of Queensland - informed him that Australia’s northern rivers were home to crocodiles as long as a whale boat (28 feet).

Another giant alive today lives in the Bhitarkanika Wildlife Sanctuary in Orissa State in eastern India. It is over seven metres (23 feet) in length and three other animals in the same sanctuary have been reported as having achieved a length of over six metres (20 feet).

Australia too still harbours giants. Malcolm Douglas, filmmaker and owner of the Broome Crocodile Park encountered such a leviathan in a northern Australian river in 1987.

“We call him the “hippo”. He dwarfs everything else I`ve ever seen. Compared with him the 16 foot 4 inch croc we did catch looked like a twelve footer…once we did have him alongside a net. The corks were three feet apart and his length covered eight corks along the net. Maybe a little more.”

This would have made “Hippo” at least 7.5 metres (25 feet) long.

In 1929 Claude Le Roy used gelignite to blow up a 7.5 metre (25 foot) crocodile in a hole just below Hartley’s Creek crocodile farm north of Cairns.

Another 7.5 metre (25 foot) monster terrorised the Staaten River for fifty years. Known as the Wyabba monster, the local Aborigines believed that it could never die, as it was part of their dreaming. Though shot at many times, the croc always shrugged off the bullets and carried on as normal. It was finally put paid to by hunter Peter Cole in the mid 1950s.

An even larger specimen persists today. At over 8 metres (around 28 feet) it inhabits the Goyder river swamps of northern Arnhem Land.

In former times such giant would have been more common. Hunting in the first half of the 20th Century reduced the number of “salties”, but since their protection in the early 1970s the species has made a spectacular comeback in Australia. Soon there may be more reports like these of giant crocs in protected areas.

The largest specimens - of a truly mind boggling size - have been met with not in rivers but in the open sea. The Indopacific is the most pelagic of all crocodiles having been encountered hundreds of miles from land. Larger than the biggest predatory shark (the great white at a maximum of 6 meters) it has nothing except man to fear.

One such sea-going encounter took place in The Gulf of Bengal in 1860. The crew and passengers of the ship "Nemesis" observed a giant crocodile at close range. One of the witnesses was the writer W.H.Marshall who described it in his book "Four Years in Burma".

"As the Nemesis was proceeding onwards towards our destination our attention was directed to an alligator of enormous length, which was swimming along against the tide `(here very strong), at a rate which was perfectly astonishing. I never beheld such a monster. It paused within a very short distance from us, it's head and nearly half it's body out of the water. I should think that it could not have been less than five and forty feet long measured from the head to the extremity of the tail, and I am confident that it was traveling at a rate of at least thirty miles an hour."

It should be noted that this animal would be an Indopacific crocodile and NOT an alligator. Alligators only occur in China and North America. However, early European colonials often used incorrect names for animals and these have stuck. In Australia the Indopacific crocodile is often referred to as an alligator and there is even an Alligator River. In Belize jaguars are called "tigers" and spider-sonkeys "baboons".

In his 1965 book In the Wake of the Sea Serpents Dr Bernard Heuvelmans catalogues reports of giant, unknown marine animals from all over the world. He puts the sightings into several categories or types of “sea serpent”. One he calls the “Marine Saurian”. It is said to resemble a gigantic crocodile, up to 18 meters (60 feet) in long and is seen in the open ocean.

Heuvelmans postulates this could be the descendent of some prehistoric marine reptiles such as a mososaur or pliosaur. I would think that these sightings would, more likely, refer to massive Indopacific crocodiles observed at sea. Perhaps when pulling a long wake behind them, their size has been exaggerated in the eyes of the witnesses.

Another man who mistakenly referred to Indopacific crocodiles as “alligators” was British sea captain and trader Alexander Hamilton. Whilst in the East Indies in 1705 his men were disturbed by “alligators” whilst working on a stage rigged alongside their ship. They fired musket balls at the creatures but could not penetrate their armour. One lucky shot finally struck a creature in the eye and entered the brain. The following day they came across the carcass on the shore. They measured it at 27.5 feet.

On 9th of March 1945, Flight Sergeant Selwyn Day saw and photographed a huge crocodile shot at the mouth of the Howard River, Northern Territories. The man who shot it said it was 28 feet long.

The crocodile is suspended on a winch attached to the back of a lorry. Two men flank it but are further back in the picture so they are of little use in estimating its size. I would say it was closer to 20 feet than 28 myself.

It is fitting indeed that the other species of crocodile with a claim to having attained monstrous proportions inhabits the dark continent of Africa. This cradle of man has a deep hold on our subconscious. If giant reptiles are to exist anywhere it must be here. Despite the depredations of the white man and the homespun wars and famines, the heart of the African continent still remains an enigma.

The Nile crocodile is the world's second largest reptile and has long been known as a man-eater. Worshipped by the Egyptians as "Sebek" the God of the Nile, and by innumerable sub-Saharan tribes, this is indeed a frightening animal.

The largest `official` specimen was shot in 1905 at Mwanza, 100km east of Emin Pasha Gulf by the Duke of Mecklenburg. It measured 6.6m (21 feet) in length. This monster, however, pales in comparison to some of the other crocodiles that have been reported by some naturalists and explorers.

The renowned wildlife photographer Cherry Kearton and his friend James Barns observed an 8.2m (27 foot) crocodile basking on a sand bank in the Semlik River. The size was estimated against other crocodiles and nearby objects. A photograph was published in one of Kearton`s books "In the land of the Lion" and apparently the crocodile in question dwarfs its companions. (The author found a copy of this book in a second hand bookshop in York. The only photo of a crocodile in the book has no other crocodiles for comparison so is of little use. The author’s copy is a sixth edition, however, and may not contain the same picture as Kearton`s original.)

A 7.93m (26 foot) specimen was claimed by a Captain Riddick who is alleged to have shot it at Lake Ksoga, and another of similar size was killed on the Mbaka River in 1903. This was recorded by the experienced field naturalist Hans Besser. At first he mistook the reptile for a huge canoe half drawn out of the water. It was 7.6m (24 feet) long but part of the tail was missing! (Perhaps it had been bitten off by an even bigger crocodile!) The body was 93cm (3 feet 6 inches) high and was 4.6m (14.72 feet) in girth. The skull was 1.4m (4.48 feet) long.

In 1954 Guy de la Ruwiere saw a 7-meter (23 foot) crocodile in the Maika marshes in the northeast Congo. The animal lifted its massive head out of the water several times. It caused a huge wave when it dived beneath the surface.

One must be careful when estimating size. My colleague Dr Lars Thomas was told by some hunters, that they had shot a 35-foot crocodile in northern Australia. Dr Thomas had the men show him the carcass and it turned out to be only 18 feet long. The men had been quite sincere, but had not brought a tape measure with them.

World famous explorer Colonel John Blashford-Snell heard tales of ten-metre (33 foot) crocodiles in Ethiopia’s Blue Nile Gorge but saw none above 6m (20 feet) himself.

One man who is very adept at estimating size is Rupert Bunce. Mr. Bunce had been a soldier in Rhodesia (now Zimbabwe) in the early 70s and one of his jobs was to intercept terrorists from neighboring Zambia. The easiest way to tell if a man was indeed a terrorist was by his boots, Zambian boots being different from Rhodesian ones. On one occasion a suspect ran into the water in the southern end of Lake Kariba in an attempt to swim away from the patrols. The ill-fated fellow was seized and bitten in two by an immense crocodile. Rupert and his companions opened fire on the giant reptile with high-powered SLR rifles. These weapons can send a bullet through a brick wall at the range of a mile. Not even the armour plate of such a monster could withstand this barrage. Once the titan lay still they drew alongside in a boat. When dragged ashore and cut open the luckless victim's legs were retrieved, he was indeed a Zambian. I asked Mr. Bunce how large the crocodile was. To my amazement he told me it was between 25 and 30 feet long (I had been interviewing him on a totally unrelated matter when we strayed onto his years in Africa). Mr. Bunce was sure of this as he was used to estimating distance and size as part of his job. Unfortunately none of the men knew the zoological importance of the specimen and no photos were taken of samples kept.

In 1960 Berkeley Rice recorded the capture of a giant crocodile in his book Enter Gambia. The 27-foot creature was caught and shot near Diabugu. Crocodiles along the River Gambia seldom exceed ten feet so this one was a monster. Sadly no one knows what became of the body.

The largest reported crocodiles on the African continent hail from that last great African frontier, the Congo rainforest, known to the Lingala and other Congolese people as "Mahamba". This lord of the jungle is said to reach a shocking 15m (50 feet) in length!

In the late 19th Century Belgian explorer John Reinhardt Werner reported sightings of giant crocodiles that lend some weight to the terrifying folk tales of the native population.

Whilst traveling down the Congo on the Aja, a 12.8m (42 foot) steam launch, Werner stopped at a sand bank to shoot ducks. He shot one and pursued others over a low ridge when he saw:

..."The biggest crocodile I have ever seen. Comparing him to the Aja which lay in deep water some three hundred yards off, I reckoned him to be quite fifty feet long: whilst the centre of the saw-ridged back must have been some four feet off the ground where his belly rested".

Werner stupidly took another shot at the ducks (they had run out of meat on the ship), and alarmed the monster, which made off into the water. The creature was also witnessed by a native boy that Werner had with him.

Around three days later Werner saw another vast specimen. The Aja had embedded itself in a sandbank when it was heaved up out of the water by something causing a commotion under the ship...

"I saw an enormous crocodile - longer I am certain than the Aja - rush across the bank and tumble into the deep water beyond. I never before saw such a large crocodile move so fast, and I had no time to get a shot at him. He must have heard us coming and was trying to make for the deep water on our side of the bank, when we ran into him and hammed him onto the sand. We struck him, moving at a rate of four miles per hour, but during the short time he was in view I could not see that he bore any marks of the collision!"

It would be as well now to pause and reflect on the dimensions of such a huge crocodile. A 7.5m (25 foot) creature would be an awesome animal in the two to three ton weight bracket. A 15-metre (50 foot) animal would be a colossal weight. When an animal doubles its size its weight increases eightfold. This is because length, breadth, depth and height have all been doubled. If we take the conservative estimate of two tons for the weight of a 7.5m specimen then an animal 15 metres in length would weigh in the region of fifteen tons - three times the weight of an average elephant! If crocodiles of these dimensions do exist then they are the largest macro-predators on the planet. Most of the great whales are plankton feeders and even the toothed sperm whale feeds mainly on small fish and squid (the giant squid forms only 1% of its diet and weighs far less than the sperm whale in any case). If they do indeed exist, there is no animal on earth that could withstand an attack from one of these giant saurians.

So far no skull, bones, or hide of any modern day crocodile approaching the length of the Mahamba has been found. The beast could be purely myth or exaggeration. The fossil record however, shows us that crocodiles can reach such vast proportions. In its current war torn, tourist-imperiling state it is unlikely that the Congo will give up its secrets. Mahamba awaits some latter day Professor Challenger to discover the truth behind it.

It is obvious that we are not dealing with whole races of gargantuan crocodiles, but a few massively large individuals. If they were prehistoric survivors of a giant race then many more specimens would have turned up!

So what is it that causes certain crocodiles to become so large? I believe that it is a combination of several factors.

Both Nile and Indopacific crocodiles have large distributions. Within their range many sub-species can exist and these may display large variations in size. A striking example is found along the Aswa River in Northern Uganda. Crocodiles here reach sexual maturity at between 1.5 and 1.8m (4.9 to 5.9 feet) and never exceed 2.1m (7 feet). This is less than half the average size. This tiny race has an unusually large head at 30.5cm long. This should yield a total length of 2.13 metres but the Aswa crocodiles fall far short of this. It seems that this is a product of prolonged periods of aestivation; the retarded development being due to inactivity. It would seem that this is a strategy that has been developed to avoid food shortages.

Other areas such as Lake Malawi, The Congo, parts of Tanzania, (such as the Grumati River) and the Semliki River in Uganda/Zaire produce larger than average specimens.

Where populations of these larger than average animals have remained undisturbed, occasional freaks will be thrown up within the genetic variation that are much larger than the average. The average man is five foot nine inches tall but a lot of the population exceed this. Most big cities have several seven-foot individuals and the record human height is eight foot 11.9 inches. A large population of "Big Crocodiles" most of whom would reach 5 metres (17 feet) could throw up 7 or 8-metre (23-26 foot) specimens occasionally.

Diet is also a factor. Once it was believed that very big crocodilians were immensely old. It was thought that crocodilians grow roughly twelve inches a year until they achieve the length of 3 metres (10 feet) when the growth rate radically slows down. By this logic, to be immensely huge a crocodile must have achieved a great age.

Actually, the greatest authenticated age for a crocodilian is a fifty six year old American alligator (Alligator missippipiensis) at Dresden Zoo.

A crocodile of unknown species died at Yetkatrinaburg in Russia a few years ago at a reputed age of over seventy but this was never, as far as I am aware, properly authenticated.

However, in a paradox, unlike mammals and birds, reptiles seem to live longer in the wild than in captivity.

Protein intake seems to have more to do with large size than age. In the early 1970s, the Louisiana department of Wildlife and Fisheries made some interesting discovery relating to diet and growth rate in the American alligator. Two groups of juveniles were reared on different diets. One was fed coypu (a large South American rodent Myocastor coypu) flesh and the other fish. Nutritional analyses showed that coypu contained 14.9% crude protein, 2.1% crude fat, 0.1% crude fiber, and 45% moisture.

Fish, on the other hand, contained 9.9% protein, 4.0% fat, 1.0% fiber, and 60.6% moisture. Specimens fed on coypu grew 20% larger than their fish fed peers over a period of three years. They were also more active and aggressive.

Food with more protein content causes accelerated growth. The Aswa crocodiles were tiny due to aestivation brought on by seasonal food shortages. In other areas where protein-rich food is plentiful all year, the average size of the crocodile population was much greater. So, if we conceive of a population of naturally big crocodiles, feeding on protein-rich prey, that occasionally produces a giant freak, whose size is increased still further by its diet, then one can conceive of a truly vast animal.

Tropical seas and teeming rain forests would offer such an abundance of prey. It can be no coincidence that the largest reported crocodiles are seen in these very habitats.

It should be noted that the Indian gharial (Gavialis gangetius) has also been credited with huge sizes. Lorenze Hagenbeck, son of the famous Karl Hagenbeck - world famous animal dealer - cited one such account. One of his friends was said to have shot a 9-metre (30 foot) gharial whose bloated carcass looked like a stranded whale! Reports of such giants in this species seem unknown today.

We will leave the last word on giant crocodiles to that gallant Victorian lady explorer Mary Kingsley, who once measured a Nile crocodile twenty-two feet three inches in length.

“Stay-at-home people will always discredit great measurements, but experienced bushmen do not, and after all, if it amuses the stay-at-homes to do so, by all means let them. They have dull lives of it and it does not hurt you.”

2 comments:

ifrit418 said...

hi there, am a real fan of giant crocodiles. Read a lot about sightings, records and random stories. Just wanted to say, the way you presented your info was really nice,no gimmicks,nice facts. I just have a question What do you think of Gustave? he supposedly ate 300 ppl and off the records a whole bunch of people who 've been thrown in the river due to the civil war raging in the country.Considering its around 60 yrs old now, you reckon he can get even bigger if left alone? Also do you think that there is a correlation between a croc's age and its intelligence?. Somehow bigger individuals keep away from human presence, they know we dangerous to them, but at the same time, they wont miss out on the opportunity to hunt us.

Brandon Sideleau said...

Interesting stuff...great job digging up all of this information. That being said...you were right at the beginning- the largest confirmed crocodilian on record was a saltwater crocodile that drowned in a fishing net in the Fly River in 1980. It was a tad over 20 feet (6 meters) in length. No other reliable measurements of giant crocodilians exist (the 28 footer from the Normanton River is credited all over the place but the fact remains that there exists little more than anecdotal evidence.)It's important to note that even 18 foot crocodiles are not by any means "common" (they only exist in river systems with large crocodile populations and even then there are usually only a handful of them.) In Africa the largest confirmed Nile crocodile was a tad over 18 feet in length. Some of these crocodiles attain immense weights and seem to gain so much mass (width) that overestimation of size is quite common. 23 foot (7 meter) saltwater crocodiles are definitely possible (dare I say, likely) but anything over that is entering the realm of fantasy. I don't think it would be possible by any biological standard for any extant species to reach 30 feet.