Category Archives: Animals

U. S. Camel Corps

Few people know that the United States had a Camel Corps. About 1836 Major George H. Crosman suggested to the United States government that camels could be used as pack animals in Florida during the Seminole Wars. Few persons in the government took this suggestion seriously but Senator Jefferson Davis was an advocate of this proposal and campaigned for it.

It wasn’t until 1855 that congress appropriated $30,000 to purchase camels. President Franklin Pierce gave his Secretary of War, Jefferson Davis, the right to make the purchase and start the experiment. On June 4, 1855 Henry C. Wayne procured camels to be shipped to the USA. The camels arrived on the east coast of the USA in late January 1856 and were finally delivered by boat to Texas in mid May.

Camp Verde, Texas was the initial camp for the camel experiment. During the experiment the camels were utilized in several capacities. They would assist in surveying projects, serve as pack animals, and assist in the rescue of snow bound wagon trains. Most of the tasks that were attempted by the corps were successfully accomplished, usually quicker and with more ease than originally estimated. The camels proved to be sure footed on rocky terrain, able to cross hot desert sands and climbed mountains faster than other pack animals. They were able to ford rivers and showed themselves to be strong swimmers. Food and water supplies for the camels could almost be ignored as camels can go without food and water for days. When they did eat, any vegetation was acceptable to them. They also showed that they could withstand conditions that other animals could not tolerate such as long hot days in the sun, rainstorms and sandstorms and still continue to advance.

There were some disadvantages of the Camel Corps. The first thing that was noted was the terrorizing effect the foul smelling, odd looking, large animals had on the horses and mules. It was said that when the camels were first unloaded in Texas the horses and mules “went berserk”. This reaction was a mixed blessing. Indian ponies also avoided approaching them, making camel caravans safer than wagon trains. Another disadvantage was that US troops did not know how to handle this new animal. Specially trained handlers had to be imported along with the animals. While a camel is usually a docile animal it can be a very stubborn, aggressive animal. Camels can make mules look like obedient puppies. It can remember a ”personal affront” for a long time and just wait until he can get even. His way of getting even can be a bite, a kick or spitting green slime.

Lieutenant Edward Beale was the man put in command of the project and deemed it a great success. One thousand more camels were requisitioned by the army but the timing was wrong. A Civil war was threatening the nation. The southern states had formed the confederacy, electing Jefferson Davis as president. The union wanted to discredit Mr. Davis and direct monies toward the war effort, so the request was ignored.

The camels that were still owned by the army were sold, released or escaped to run wild. Feral camels were reported from time to time throughout the west and British Columbia until well into the 1900’s. The last sighting was reported in 1941 in Douglas, Texas.

From a paleontological perspective, it makes a lot of sense that camels would adapt themselves to conditions in North America—they originated here after all. Camels first appear in North America about 45 million years ago, and migrated to Asia and Africa about 7 million years ago. Then, like the horse, camels became extinct in their native continent at the end of the Ice Age.

Shark Bites in the USA

The USA has the most reported shark attacks in the world. What could be the reason for this? Are Americans so well nourished that they taste better? Could be, but all the references I have read say that a shark attack is most probably an “accident”. The shark had mistaken the human for his more usual meal such as a seal or another fish.

One reason the United States is at the top of the list is that the U.S. has a very large combined coastal shoreline. Another reason is the increase of recreational marine activities, and recreational marine activities expose people to all aquatic dangers including shark attacks.

No doubt, a high level of reporting of attacks is also a factor. Not all coastal countries publish a complete record of shark attacks. Publishing such reports could adversely affect the tourist trade. In addition to the USA some of the other countries that have reported shark bites are Africa, Central & S Am, Australia and Pacific Islands.

In the U.S 60% of all shark attacks are reported by the state of Florida. California reports about 15%, this is closely followed by Hawaii. Most coastal states have at one time or another reported a shark attack. Most of the attacks are not fatal. Most of the attacks are done by a contact bite, then the shark swims away. The victim can be left with a maiming wound or deformity. Fatal attacks are mainly due to the bull shark, tiger shark, or the great white shark and the Oceanic white tip shark. (Pictures and information about these sharks can be found at Dangerous animals–Sharks). In recent years the entire east coast has had a growing problem with aggressive sharks. The reason for the increase is being researched.

Overall shark attacks are extremely rare – “Lightning strikes humans more often than sharks bite humans”. The International Shark Attack File reports that world wide there are 50 – 70 unprovoked shark attacks a year. The number of shark attacks is increasing because the human population is increasing and recreational use of the shark habitat, oceans and coastlines, is increasing. Even though there are 50 to 70 attacks a year the number of fatalities are low.

Wikipedia has a list of the fatal, unprovoked shark attacks in the US. The records start in 1779 up to the recent. The more recent records state the age of the victims and other information that is interesting reading and gives some explanation of the event. A summary of the records show that there were 13 deaths from 2000 to 2010. Three of the years, 2002, 2006 and 2007, did not have any deaths. The years 2001 and 2004 had 3 deaths each. So far in 2010 there have been two reported deaths due to shark bites, but the year is not over.

What to call the giant cat from the Ice Age?

The Ice Age of the recent past was a fascinating time, full of superlative animals, especially the mammalian megafauna of North America. The Ice Age, also referred to as the Pleistocene epoch, lasted from 1.9 million years ago to 10,000 years ago, and was characterized by a series of glacial advances and retreats across much of the Northern Hemisphere. It was also a time of animal migrations between continents and of many species being exceptionally large.

Giant ground sloths, the giant short faced bear, saber-toothed cats, mammoths, and mastodons all tromped through what was to later become our backyards. Many people are surprised to learn that North America was also home to a very large cat, larger than the modern lion, given the scientific name Panthera atrox.

This big cat lived mostly across the western half of North America, and ranged into South America as far as Peru. Its remains are plentiful in the tar pits of Rancho La Brea. It is clear that this is a big animal. Estimates of body size suggest a weight of about 1,000 pounds, and that it stood 4 feet at the shoulder. For comparison, the modern African lion weighs in at about 375 pounds. This American cat would have been the second largest mammalian predator, right behind the giant short faced bear. (See How big was the Giant Short-faced bear?)

The giant American cat, Panthera atrox

However, understanding how this animal relates to other large cats has been difficult. Scientists have noticed similarities between P. atrox and the modern lion, tiger, and jaguar. For many years, P. atrox was thought to be a subspecies of the lion, and so it has popularly been called the American Lion, and even the American Cave Lion. If it is closely related to the African lion, it suggests that lions migrated out of Asia and into the New World during the Ice Age, expanding as far south as South America, and becoming extinct at the end of the age. Several other species are known to have done this, so that is not so unusual. But is it an accurate story?

In a recent paper on the subject (Christiansen and Harris 2009), researchers have come up with a different idea. They examined the skull and jaws of the big American cat and compared it with lions, tigers, and jaguars. They used a wide range of measurements to create a mathematical model of each species, and compared them to each other. The result? Panthera atrox does not seem to be a lion at all, but rather is closest to the modern jaguar.

Jaguars came into the New World from Asia during the early Pleistocene. It seems then that P. atrox and the modern jaguar species, P. onca, are derived from the early jaguar that came into North America, and that lions never made that long trek across. If these researchers are correct, we should not call this magnificent cat the American Lion.

A jaguar, Panthera onca. By Pascal Blachier from Savoie, France.

So, what should we call it? Jaguars are native to the New World, so the word “American” seems a bit redundant in the name. And the simple scale and grandeur of the cat requires some adjective. “Mega Jaguar” seems a bit plain to me. What do you suggest?

Christiansen, P. and Harris, J. M. 2009. Craniomandibular morphology and phylogenetic affinities of Panthera atrox: implications for the evolution and paleobiology of the lion lineage. Journal of Vertebrate Paleontology 29(3):934-945.

Mammoth protein designed to be cool

Researchers were recently able to isolate and study woolly mammoth hemoglobin and compare it to the modern African and Asian elephants. They isolated the genes from DNA that code for the creation of hemoglobin, the protein that carries oxygen in our blood. This was done for both the modern elephant species, as well as from DNA from mammoth bone from Siberia. They observed some minor differences between all the species, so the researchers wondered if the difference in the mammoth’s blood might have helped it survive in cold climates.

Hemoglobin supplies our body with oxygen by carrying it around in our blood stream and then releasing it to our tissues. When our tissues need more oxygen, like for muscles that are working hard, hemoglobin more easily releases oxygen because of the higher temperatures created by the heat generated by the muscle. However, in colder temperatures, hemoglobin does not give up oxygen as easily. This is potentially a real problem in colder climates. To keep the hemoglobin to working effectively an animal might need to expend valuable energy to maintain a higher body temperature.

The researchers (Campbell et al. 2010) wondered if the slight differences in woolly mammoth hemoglobin might have been an adaptation for living in colder temperatures. They inserted the Asian elephant genes that make hemoglobin into the common bacteria, Escherichia coli, and allowed the bacteria to act on the genes, thereby making Asian elephant hemoglobin. This process is not new as it is commonly used to have bacteria produce proteins that are identical to human-made proteins, like insulin.

To get the bacteria to make mammoth hemoglobin, they needed to modify the Asian elephant genes the same way they observed, then let the bacteria make the hemoglobin of a mammoth—thousands of years after the mammoths last did it themselves. Researchers could then compare the protein of the two species directly. The result was that mammoth hemoglobin released oxygen much more effectively at lower temperatures.

Woolly mammoths from Alan Turner (2004), National Geographic Prehistoric Mammals.

Woolly mammoths were adapted to colder climates in a number of ways, such as compact bodies, small ears, short tails, and long woolly hair. This result strongly suggests that their bodies were also changed at the molecular level for life in cold, high latitude climates during the Ice Age. It would be very interesting to see if other mammoth species, such as the Columbian mammoth, for example, shared this adaptation. But I suppose that will have to wait until we can get good DNA from that species. All in good time.

Campbell, K. L. et al. 2010. Substitutions in woolly mammoth hemoglobin confer biochemical properties adaptive for cold tolerance. Nature Genetics 42:536-540.

Two dinosaurs become one

Earlier this year a paper was published (Scannella and Horner 2010) on one of the most well-known dinosaurs of the Late Cretaceous, Triceratops, updating our understanding of not only this dinosaur species, but also maybe influencing our view of many other dinosaur species as well.

Triceratops as mounted at the Carnegie Museum of Natural History

Triceratops was first described in 1889 by O. C. Marsh, and has become one of the best represented dinosaur species in terms of numbers of fossils recovered. Their remains are very common in the Hell Creek Formation of Montana and the Dakotas. And, Triceratops has been known by practically every kid for the last 100 years, being well represented in dinosaur movies and dinosaur toys the world over.

Triceratops is best known for its three horns and neck frill of bone. Torosaurus, another dinosaur that is obviously related to Triceratops because of its similar appearance, was also first named by Marsh in 1891. It is found in the same geologic units in the same region, but is much less commonly found. Torosaurus was much larger than Triceratops, and had large openings in the neck frill, and its horns pointed more anteriorly.

So, for over 100 years paleontologists thought there were at least two species of horned dinosaurs in these beds. But scientific understanding makes progress. In the early “bone rush” days of the nineteenth century the game was naming new species. Today, there is a trend of relooking at those species to see if they are in fact different.

"Torosaurus" mount at the Milwaulkee Museum, now should be called Triceratops.

This is where the new study comes in. The authors examined Triceratops and Torosaurus and questioned whether they might not be the same species, but at different life stages. It has become apparent that individuals of a species can change a great deal over their lifetimes. A newborn human does not look much like an adult in body proportions, for example. If past species also changed significantly over their lifetimes, the different stages could easily be mistaken as completely different species. And that seems to be the case here.

By looking closely at the trends of skull shape and indicators of maturity, Scannella and Horner believe that in fact Torosaurus individuals are older and more mature individuals of Triceratops. This means that later in their development individual Triceratops specimens changed significantly as they reached maturity, developing the large openings in the neck frill and increasing in overall size.

The implications for other dinosaur species are clear. If individuals can change dramatically during their lifetimes as they mature, perhaps there are many named dinosaurs that are not truly different and unique species, and we need to match youngsters with adults. No doubt this will keep paleontologists busy for the next 100 years.

And in case you are worried, the name Triceratops will remain, since it was the first name given to the species that we now realize includes those individuals that one were called “Torosaurus.” So, despite some headlines Triceratops did (and still does) exist!

Scannella, J. B., and J. R. Horner. 2010. Torosaurus Marsh, 1891, is Triceratops Marsh, 1889 (Ceratopsidae: Chasmosaurinae): synonymy through ontogeny. Journal of Vertebrate Paleontology 30(4):1157 – 1168.

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Exploring the natural world