Category Archives: Mammals

Geographic Insights about Big Bear Lake

Most visitors to Big Bear Lake come from the urban sprawl of Southern California, city dwellers at heart. Few have a real appreciation of the underlying geology or geography that circumscribes the place they visit for the rest and recreation found at Big Bear. They are exquisitely well positioned to appreciate the built environment, from the lakeside marinas to the range of lodging at Big Bear Lake. But the natural environment is not well understood.

There’s something really special about Big Bear and its environs. Nestled in the mountains, this 7 mile long alpine lake, which originally existed as a shallow lake and marsh (before the dam made it deeper), drains a watershed stretching from the high desert on the northwest (see California Tourist Guide for maps and info about Deserts and Inland Empire) to the Santa Ana river watershed to the east. It’s located at a high elevation (6,750 feet at lake level), which means that it stays cool/cold year round and thus explains the extended skiing season available for 6 months a year, even though it is near to balmy Los Angeles.

In fact, the elevation explains the heavy precipitation, too. Big Bear receives about 5 feet of snow a year, and some years can be almost double that. While that’s great for skiing, the principal value is feeding the fresh water of the lake itself, sustaining the fish population in the lake and the verdant flora along the entire watershed.

The fauna of the region have been distorted by human development so that what exists now is hardly what existed for so many years. While one can find the occasional coyote, you would be hard pressed to find a bear … and the original European settlers named the valley for a reason: in pursuit of some cattle thieves, Benjamin Wilson, an early pioneer, took 22 pairs of men into the canyon … and they came out with 22 bear hides. Needless to say, the population of California brown bears and grizzly bears has been severely reduce

The other feature of the natural environment worth mentioning is mining. After the gold rush in Northern California, several efforts were made to look for gold in the San Bernadino Mountains, starting in 1859. Bear Valley delivered some bear meat for the prospectors (those poor bears!), but the gold strike was found in Holcomb Valley, 5 miles to the north, not in Big Bear (Lucerne) Valley. That was probably best in the long run, as no significant ecological destruction occurred in Bear Valley, unless you count the extirpation of the Grizzly Bear in the early 1900s.

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.

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.

Dangerous animals—bears

Truth is stranger than fiction. The most recent human fatality caused by a bear took place in the wilds of Ohio. Well, sort of the wilds—just outside of Cleveland.

It seems that a young man, Brent Kandra, was tending to a captive bear when the bear attacked and killed him. The bear was owned by a man who has kept exotic animals for display in the past, and the event has sparked debate about the wisdom, and regulation, of large exotic animals being kept by private individuals (Associate Press 2010).

Whether in a cage or in the wild, bears are undeniably dangerous animals. This is the next in our series exploring dangerous animals. Unlike most of the other species we have looked at whose danger to humans is really more imagined than real, bears do come in contact with humans with some regularity, sometimes with unfortunate consequences.

In North America there are three bear species: the black bear (Ursus americanus); the brown bear (Ursus acrtos); and the polar bear (Ursus maritimus).

Black bear in the Canadian Rockies

Like so many common names, the name black bear is really not very good since the animals are often many other colors than black. The fur comes in shades of blond, black, brown, cinnamon, and gray. Interestingly, the bears tend to be black in the eastern forests, and more color variation is introduced as you survey the populations to the west, such that in California most of the bears are brown.

The black bear is the smallest of the bear species, and the most common, with the widest current distribution. They are found across Canada and south through New England into the Appalachian Mountains. There are populations in the Ozarks and in the southern states. In the west they can be found through the Pacific Northwest, and through the Rocky Mountains south into Mexico.

Black bears are generally shy and reclusive, but they can become accustom to humans, especially when they learn to associate human activity with food—through trash or handouts. In many backcountry areas where bears are common officials try to keep bears and people separate, but it is not always possible. Food storage is a great concern when camping. For example, while camping at one remote location in the Great Smoky Mountains campers were to hang their food from a cable over a stream.

Hanging a food pack over a stream in bear country

Incorrectly hanging your bag could lead to a bad time.

Results of improperly hanging your food pack

Brown bears are similarly misnamed, although the color variation is less dramatic than their black bear cousins. There are several subspecies, or races, of brown bears that you may have heard of, dividing them into coastal Kodiak and inland grizzly populations, but they are all the same species.

Brown bear

While once much more wide-spread in their distribution, brown bears are limited today to Alaska and northwest Canada, with several populations in western United States parks such as Glacier and Yellowstone.

Encounters with polar bears are understandably rare given the remoteness of their habitat. (See why polar bears are sensitive to climate change.) Polar bears spend much of their time out on sea ice, hunting seals. However, unlike other bear encounters, most encounters between humans and polar bears seem to be motivated by predation—that is, the bear is looking to eat them.

Bear encounters do sometimes lead to injury or even fatalities, and as people spend more time in bear country, the chances for an encounter naturally go up. In encounters that go badly, injury is more common than fatality as bears most often attack when they feel threatened, and once the threat is over they tend to leave. Rarely do bears prey on humans as a food source, but it does happen. In general there are about 1.8 bear-caused fatalities per year (see Clark 2003, Gunther and Hoekstra 1998, Herrero and Fleck 1990, Herrero and Higgins 1999 for discussions).

Of the dangerous animals discussed in the series, bears are the ones that most people need to be aware of, and to think about when entering the woods. Do not do stupid things in bear country, like walk around imitating the sounds of animals to attract bears (yes, it has happened), improperly store your food, try to feed the bears, get too close while taking pictures, or tease or taunt the bears. Common sense and awareness that these majestic creatures are sharing our woods will ensure that your adventures will have only the typical amount of excitement.

Associate Press. 2010. Bear who mauled caretaker is put to death in Ohio. NPR. http://www.npr.org/templates/story/story.php?storyId=129321688.

Clark, D. 2003. Polar Bear – human interactions in Canadian National Parks, 1986-2000. Ursus 14(1):65-71.

Gunther, K. A., and H. E. Hoekstra. 1998. Bear-inflicted human injuries in Yellowstone National Park, 1970-1994. Ursus 10:377-384.

Herrero, S., and S. Fleck. 1990. Injury to people inflicted by Black, Grizzly or Polar Bears: recent trends and new insights. Bears: Their Biology and Management 8:25-32.

Herrero, S., and A. Higgins. 1999. Human injuries inflicted by bears in British Columbia: 1960 – 97. Ursus 11:209-218.

Boneblogger: Science and the outdoors

Exploring the natural world