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sexta-feira, 13 de março de 2020

Of mammoth proportions: the difference between mammoths and mastodons

Spot the difference!


 
If you’ve ever visited a natural history museum, you might have seen a grand skeleton tower over you, with giant tusks gently sloping to the sky and a shape reminiscent of an elephant. Perhaps you thought immediately of a woolly mammoth, the most famous elephant relative, popularized by Manny, the grumpy mammoth in Ice Age. However, there is another relative that you most certainly have also heard of: the mastodon.
Although similar, there are key differences between mammoths and mastodons.
An impressive mammoth skeleton. Image credits: Kelley Minars.

Origin of mastodons and mammoth

First of all, mastodons came into existence much earlier, about 27 to 30 million years ago. Mammoths are “young” by comparison, having emerged a mere 5.1 million years ago in Africa. There were multiple mammoth species, but the famous woolly mammoth is the baby of the bunch, emerging only 250,000-400,000 years ago.

Mammoths could be found across Eurasia and North America. Mastodons were not so widespread and called North and Central America their home (still a considerable area considering that they could be found from Alaska to central Mexico).
Although mammoths preferred cooler temperatures and mastodons preferred warmer temperatures, they both lived in Beringia, the land between East Siberia and Alaska that wasn’t covered by ocean during the Ice Ages. 

They lived there at the same time during the early to mid-Pleistocene, but the mastodons left because it got too chilly for them. Mammoths still survived in Beringia until 13,000 years ago, and a subset that evolved to be small (about the size of a large horse) survived on arctic islands until as recently as 4,000 years ago

To put it into perspective, the Great Pyramid was being constructed around the same time mini mammoths were ruling an arctic island — as crazy as it sounds, mammoths and the pyramids were around around at the same time (for a brief period).


Lifestyle differences

Mammoths and mastodons led different lifestyles and their appearance reflects these differences.
Mastodons lived mainly in forests. Accordingly, their teeth have cone-shaped cusps, perfect for crushing leaves and twigs. Sometimes, the plants that animals eat are also preserved alongside their fossil remains. Researchers who have quantified mastodon gut contents have found a lot of twigs from coniferous trees, while another study found mostly low, herbaceous vegetation in their guts. Therefore, they likely browsed and grazed, changing their preference based on the season and where they were.
A mastodon depicted in its forest habitat. Image credits: Heinrich Harder (1858-1935).
Mastodons were named for the shape of their teeth. The French taxonomist Georges Cuvier apparently thought that the teeth looked like breasts so he derived their name from masto (“breast” in Greek) and odon (“teeth” in Greek).
Mastodon teeth. Image credits: Jstuby.
On the other hand, mammoths are much more closely related to modern-day elephants than mastodons, and lived a similar lifestyle. They also used to live on large, open plains and had flat teeth with ridges for grazing. Elephants also have similarly shaped teeth. Mammoths mostly ate flowering plants because they contain more protein and are easier to digest than grasses. Some species of mammoth also munched on other types of vegetarian fare, such as cactus leaves, trees, and shrubs.
A baby mammoth preserved in the permafrost also brought to the light that baby mammoths ate their parents’ dung because it is easier to chew, like elephants living today do.
Mammoth tooth. Image credits: James St. John.

Physical differences between mammoths and mastodons

Though mammoths and mastodons were both large, hairy, elephant-like creatures, they did have some differences other than their tooth shape. Mastodons were a bit shorter and stockier. Since mammoths tended to live in colder climates, they had fatty humps where they stored extra nutrients necessary to survive the long, frigid winters and warmer fur coat. Mammoth tusks curved more while mastodon tusks were straighter and shorter.
Mammoths had a distinctive bump at the top of their skulls while mastodons had flatter heads. There were multiple species of mammoth (not just the woolly mammoth!) and mastodon that varied slightly in different aspects of their appearance — skeletal and dental differences, for example.
A face-to-face comparison of the mammoth (left) and mastodon (right). Image credits: Dantheman9758.

Extinction

Although mastodons evolved earlier than mammoths, both went extinct at a similar time, about 10,000 years ago.
There is some disagreement between experts about what exactly brought about the demise of these gentle giants — but there are two prevailing theories.
The first is that they were unable to survive due to increasing temperatures after the end of the last ice age 12,000 years ago. Glaciers retreated and sea levels rose, with the warmer temperature causing the environment to change. Forests grew up where open woodland and grasslands had been. The arctic tundra and steppe were dominated by flowering plants, but when the climate became wetter and warmer, they were replaced by grasses, which were not so nutritious or easy to digest for mammoths.
However, some researchers argue that similar warming periods had occurred over the past several million years within the ice age without such disastrous consequences. Therefore, the second theory is that someone new on the scene played a large role in their demise, more specifically, humans.
There is evidence that Homo erectus ate mammoth meat 1.8 million years ago, but this could be a result of scavenging as opposed to active hunting. 

Some sites created in the past 50,000 years in Eastern Europe and Britain present further evidence that humans hunted mammoths: dwellings made from mammoth bones and mammoth remains. The spread of more skilled human hunters around Eurasia and North America coincided with the disappearance of mammoths and mastodons. However, these creatures lived across such an enormous area, including remote areas of Siberia, that it is uncertain if humans with primitive weapons would have been able to decimate them.
Did humans hunted the mammoth to extinction? Image credits:
http://cloudinary.com.
It is more likely that the combination of a changing climate and human hunters led these giants to their end. The shrinking of suitable areas to live likely caused many to die out, rendering the remaining populations more vulnerable.
All in all, mammoths and mastodons lived different lifestyles, but still looked quite similar, except for some special adaptations for their diet and climate. They also share similar causes for their demise. Now, on your next visit to the natural history museum, see if you can guess if that big, tusked skeleton is a mammoth or mastodon. 

https://www.zmescience.com/other/feature-post/of-mammoth-proportions-the-difference-between-mammoths-and-mastodons/

terça-feira, 15 de janeiro de 2013

The 7 Magnificent Elephants of Kruger

http://blog.africageographic.com/safari-blog/bush/the-7-magnificent-elephants-of-kruger/

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Information for this post courtesy of SANParks
Over thirty years ago seven impressive elephant bulls, all with tusks weighing more than 50 kg each, could be found in Kruger National Park.
Dr. U de V Pienaar – the Chief Warden at the time – decided to publicise these elephants as a successful example of Kruger’s conservation work.
He named these bulls The Magnificent Seven…
Over time the tuskers became well-known, and now, many years later, they are still remembered as some of the most glorious animals in Africa.
These are their stories:

Dzombo (c.1935–1983)

dzombo
The word Dzombo is derived from the Tsonga word Dzombolo meaning ‘to wait for something that is slow in coming’. This elephant was named after the Dzombo stream that traverses the Mopani Flats between the Shingwedzi and Shawu valleys.
Dzombo was the only one of the “Magnificent Seven” to be killed by poachers and it was only by a stroke of luck that Dzombo’s two tusks were not taken. He died in a hail of bullets from an AK 47 fired by a poacher from Mozambique in October 1985. The miscreants were in the act of chopping out the tusks when they were disturbed by the approach of Ranger Ampie Espag and fled leaving their trophies behind. Dzombo met an untimely death at the age of 50 years.
(Dzombo’s tusks are on display in the Letaba Elephant Hall)

João (date unknown)

Joao
Named by Anthony-Hall Martin for Prester John, legendary priest-king of ancient Africa. (João being the Portuguese for ‘John’) João was a very large bull, with a shoulder height of 340cm.
João was wounded by poachers in 1982, at this time he was immobilized to investigate the damage. Fortunately the wounds were not fatal, and after a dose of antibiotics and cleaning of the wounds he was revived. While immobilized he was fitted with a radio collar and measurements of his tusks taken, he tusks were an estimated combined 130kg which at the time would have made him the heaviest ivory carrier of the Magnificent Seven.
In 1984 (approximate age, 45 years) João broke both tusks close to the lip line (20-30cm), presumably in a fight with another bull. Unfortunately the pieces were never found and as a result João is the only member of the Magnificent Seven who is not represented in the Letaba Elephant Hall.

Kambaku (c.1930-1985)

kambaku
Kambaku is the Tsonga word for ‘Great Tusker’ or ‘Old Elephant Bull’.This bull moved over a huge tract of country stretching from Satara/Orpen and the Timbavati to Crocodile Bridge.Kambaku’s left ear had a perfectly round hole in it close to the outer edge, and towards the end of his life he had no tail hairs.Kambaku was the third member of the Magnificent Seven.
Uniquely unlike several of the other Magnificent Seven bull, Kambaku was always seen alone. He was more than 55-years-old when he was shot in late 1985 by Regional Ranger Lynn van Rooyen from the Lower Sabie Ranger Section. The bull was in obvious pain from a bullet wound suffered during a foray across the Crocodile River into a neighboring sugar cane fields. The bullet penetrated his left shoulder, leaving a large wound which eventually became septic. When he could not longer walk and it was clear that death was imminent, he was mercifully shot.
(Kambaku’s tusks are on display in the Letaba Elephant Hall)

Mafunyane (Carcass discovered 16th November 1983)

Kruger-National-Park-low-res-copyright-Scott-Ramsay4

This bull was named after former warden of the Kruger National Park Lou Steyn who was well known for his quick temper. (Mafunyane is the Tsonga word for ‘the irritable one’ which appropriately refers to the elephant’s disdain for, and intolerance of humans.)
(Kloppers & Bornman (2005) (A Dictionary of KNP Place Names) gives the meaning of the name as “One who eats greedily”)
Mafunyane’s tusks are fairly straight and their tips are worn to a chisel-edge by as a result of being rubbed on the ground as he moved. His tusks were perfectly symmetrical and of identical length and mass. The bull had a 10cm hole in the right side of his skull that extended into his nasal cavity allowing him to breathe through this passage. One of his toes on his left hind foot was splayed to one side so that he left a distinctive impression, distinguishable from other elephants.
Mafunyane was the most famous of the “Magnificent Seven” although he was only seen in the wild by a handful of people, and was rarely seen by visitors as he kept well away from roads. This could be attributed to his shyness or to the fact that he chosen roaming area was very remote.
The immobilization of Mafunyane on the 8 June 1983 to fit a radio collar and to make plaster cases of the bull’s ivory nearly spelled the end for this bull. When given the antidote to the immobilization drugs Mafunyane due to his immense tusk size was unable to ‘rock’ himself onto his chest which would have allowed him to stand up, and his repeated efforts caused him to dig his tusks further into the ground. Several strategies were tried to raise him but all failed. After he had been down for several hours and front end loader was brought into assist the team. Mafunyane was eventually ‘scooped’ to his feet and the bull rose and ran into the nearby Mopane bushes much to the relief of the capture team.
Mafunyane’s remains were found on 16 November 1983 near Tari River, Northwest of Shingwedzi. He had been dead for approximately 3-4weeks and appeared to have died of natural causes. He was about 57 years old when he died.
(Mafunyane’s tusks are on display in the Letaba Elephant Hall)

Ndlulamithi (c.1927–1985)

ndlulamithi
Ndlulamithi earned his name from his appearance, which is a traditional Tsonga word meaning “taller than the trees”.
The handsomely curved tusks of Ndlulamithi, the left one sweeping low and well forward, are significantly more twisted than those of the other large bulls. He was considered a tall Elephant probably around 340 – 345cm high at the shoulder.
Ndulamithi was first identified in 1980 along the Nkokodzi River in northern Kruger National Park. He was an aggressive yet secretive elephant, and was seldom seen. This bull received some fame for charging Dr Anthony Hall-Martin and his assistant while they were trying to photograph him on foot, his intentions unmistakable. He died of natural causes in 1985 in the Shangoni area at an estimated 58 years of age. Paul Zway section ranger of Shangoni at the time found his remains not far from the Nkokodzi Spruit.
(Ndulamithi’s tusks are on display in the Letaba Elephant Hall)

Shawu (October 1982)

Kruger-National-Park-low-res-copyright-Scott-Ramsay-210

The “Shawu Bull” was named after the Shawu valley (Vlei) in which he spent much of his life.
Shawu moved over a large range which spanned the flat Mopani covered plains country between the Letaba and Shingwedzi rivers and stretched from the main road to Lebombo Hills. He did not however, cover this enormous area regularly, but drifted around slowly, taking about 6 months to move from South to North.Shawu’s tusks are the longest on record in the Kruger National Park and one of the 6th longest to ever come out of Africa.
Shawu was a fairly approachable animal and showed no particular fear or distrust of vehicles. He was a large bull having a shoulder height of 340cm. Due to the pincer formed by his large tusks he was sometimes referred to in Afrikaans as “Groot Haaktand”. In 1981 it was decided to fit Shawu with a collar as poaching was a constant threat from Mozambique, this was successfully and he was monitored on a regular basis.
Shawu died of old age in the Kostini area east of Shingwedzi, near the northern watershed of the Shawu Valley (Vlei) in October 1982. He had been ill for some time and his condition and movements were monitored daily towards the end of his life by means of a radio transmitter which had been fitted in a collar around his neck. He was close to 60 years old when he died.
(Shawu’s tusks are on display in the Letaba Elephant Hall)
Kruger-National-Park-low-res-copyright-Scott-Ramsay-410

Shingwedzi (c.1934-1981)

shingwedzi
Shingwedzi was named after the river and rest camp where he spent the last few years of his life. (Shingwedzi means, “place of ironstone” referring to the gabbro rock outcrops common to the area. Shingwedzi is derived from the Tsonga word Ngwetse which means ‘the sound of metal objects rubbing against each other’).Shingwedzi’s ivory offers a good example of the classic master servant tusks. He had a large right servant tusk and a shorter left master tusk.
Shingwedzi was found dead under a Sycamore Fig and short distance from Shingwedzi camp in January 1981, and as far as can be determine he died of natural causes. The age of an Elephant can be fairly accurately determined from the state of wear of the teeth. In the case of Shingwedzi the last molar (molar 6) was well worn down, giving him an estimated age of 65 (56) years.
(Shingwedzi’s tusks are on display in the Letaba Elephant Hall)
Information for this post courtesy of SANParks
Keen to visit South Africa? Check out Kapama Buffalo Camp , one of Africa Geographic's Special Places.