Short-faced Bear
Short-faced Bear

NPS Photo/ Portion of a Matternes Mural

The Bear Facts About Hagerman Fossil Beds N.M.

Everyone expects units of the National Park Service to have bears! There are grizzlies in Glacier, black bears in Great Smokey, and Yellowstone has both. For those interested in Hagerman Fossil Beds you'll be glad to know that we do too. Of course. our bears are said to be more than 3 million years old so they don't eat much, which is a real advantage to the rangers because we don't have to worry about visitors feeding them.

Unlike the other parks, our Hagerman bears are rare and won't be a common sight to visitors. In fact they are so rare that in the 65 years that paleontological research has been conducted here, only two bones have been found, a lower jaw and the part of the upper arm bone (humerus) that fits into the elbow joint. As you might imagine, with an animal this uncommon, there was quite a bit of excitement, when Hugh Harper, one of the park' s VIPs found another partial bear humerus while helping the park paleontologists conduct survey work on the monument.

Comparison of our new find with illustrations in the scientific literature confirmed our initial suspicions. The new find is not from a relative of the black or grizzly bear, but rather is related to the Spectacled Bear that today lives in parts of northwestern South America. This is one of many animals found at the monument that forms part of our South American "connection".

As continents are pushed by the tremendous pressures within the earth, horizontal movement and/or uplifting of land masses occur. North America and South America were once separated by ocean, and later the land was pushed above sea level. The Isthmus of Panama formed a land bridge between the two continents. Once this connection was made many animals moved between the two land masses resulting in a "faunal interchange". The Spectacled Bear is typically thought of as a South American mammal, but its ancestors came from North America. The llama and peccary are other examples of animals that migrated south across the Isthmus of Panama. The llama later became extinct in North America.

A few mammals migrated north via the Isthmus. For example, the ground sloths found fossilized in the Monument originated in South America.

Although not the smallest of the living bears, Spectacled Bears are not very large either. A big male Spectacled Bear is about the same size as a large female black bear. Measurements of the newly found bone indicate an individual a little larger than a living male Spectacled Bear and it may have weighed about 175 kilograms (385 pounds). The female was probably much smaller. Like many bears, living Spectacled Bear males are about twice as big as the female. This difference in size is also seen in the extinct species, Tremarctos floridanus, so it was probably also true for our Tremarctos here at Hagerman. Unfortunately, with only two examples of the same bone, we can't say for sure, but based on its larger size, our new bone may have come from a male.

The living Spectacled Bear is the most herbivorous of all living bears. Fruit, along with leaves and roots, makes up a major portion of its diet. We don't have any direct evidence of what our Hagerman bear's diet included but scientists tell us that 3.5 million years ago this area's climate was much wetter. With a wide range of vegetation, it probably provided a good salad bar to support an animal with tastes similar to the living Spectacled Bear. Perhaps, as we continue our work on the monument, more remains of this elusive animal will show up and we'll get some more information. So, bear with us 'til then.

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Last updated: November 22, 2016

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Hagerman, ID 83332


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