Category Archives: Beavers

Devil’s Corkscrews

Daemonelix_burrows,_Agate_Fossil_Beds

I stumbled onto devil’s corkscrews on my way to something else. I thought you might enjoy my  further exploration of the strange formations. In the mid-1800s early ranchers in Sioux County, Nebraska were discovering spiraled tubes, up to nine feet long, which they nicknamed “devil’s corkscrews,” more formally, Daemonelix.

What were they? Only when teaching children at the Florida Museum of Natural History did I learn about trace fossils, evidence that something had been in a place: a footprint or leaf print, a burrow, coprolite (fossilized poop). The ranchers’ fossils were remnants of spiral burrows dug by rodents found at the spiral base. They had super long front teeth like modern beavers, with stubby tails instead of paddles like the modern beaver. These clever little rodents burrowed near water, but instead of digging straight down, they dug spirals, making it harder for predators to reach them, and perhaps, slowing water.

Paleocastor, which means “ancient beaver,” died out during the Oligocene when the planet cooled down and dried out. Could he not adapt from the wet world he knew to the grasses and prairies? Then why did some aquatic beavers survive to become great dam builders? What do you think?

You can visit Agate Fossil Beds National Monument in Nebraska or check out nps.gov/agfo/learn/nature/mammalfossils.htm to see more interesting (extinct) critters.

Who Killed Cecil the Lion?

Can we really throw stones at the dentist who killed Cecil, Zimbabwe’s iconic lion? Until the late Pleistocene, 10,000 years ago, lions were the most widespread large land mammals, after humans, ranging from AlaskaLion_waiting_in_Namibia to Peru, and throughout Asia and Africa.* Think about it! Lions roamed where we once lived! So did mammoths, mastodons, giant ground sloths, ten feet tall terror birds, rhinos, bison, hippos, camels, beardogs and glyptodonts, resembling giant armadillos. Where did they all go?

At one time, North America was home to more mega fauna than Africa. What happened to them? Granted, some, like the horse which originated here, migrated across the Bering Straits, and a newly formed isthmus to South America. Ice ages (there were at least five) had an effect. Parasites could easily decimate a whole herd. On school tours at the museum, I ask the children which do you think had the greatest impact? chill, kill, or ill? Invariably, they choose kill. Why? Do they know their own species so well?

Maybe. Remember the stories of 19th century train passengers shooting bison from the windows for sport? Those who couldn’t experience the west lived vicariously through “wild west shows,” like “Buffalo” Bill Cody’s, he who reportedly slaughtered more than 4,000 bison in two years.

We are not the only species that kills for reasons other than food. Cecil’s rival, another adult male, has killed Cecil’s cubs, which will assure less competition for his own progeny, a strategy not unknown among humans. Humans are adaptable. We’re resourceful. That’s why we remain at the top of the food chain. But killing for the thrill of the kill is less than human. The pride probably ate the murdered cubs. Humans are one step above cannibalism, but my friend Kaye would say we carnivores are not.

According to the International Union for the Conservation of Nature, lion populations in Africa are in serious decline, mostly from human intervention. Lions have suffered a population reduction of approximately 30% over the past two decades (approximately three lion generations). Whether a species is endangered or not, what does it say about us as a species to have trophies of animal heads on the wall? Think about it! 

*C.R. Dick Harrington, Canadian Journal of Earth Sciences, vol. 6

Picture credit: Kevin Pluck at Okonjima AfriCat Foundation, Namibia

Beaver Attacks Men

You knew about the big teeth. You knew about the wide, flat tail. But who knew beavers could be aggressive? On June 26 the AP reported a beaver attacked two Oregon men, who then fell into the river. The men had climbed onto a beaver dam and were attacked by the animal. Their injuries were not life-threatening, but I bet they won’t be visiting any more beaver homes!beaver-w-branch-1

Beavers dam streams to create productive wetlands. According to Beavers: Wetlands & Wildlife, almost half of endangered and threatened species in North America rely upon wetlands. Wetlands ease flooding, lesson erosion, and purify water, lessening treatment for human use. Wetlands are an economic boon, and by creating and maintaining them, beavers provide essential services to people.

A Native American word for beaver also means “affable,” a word which, under normal circumstances, describes the demeanor of the intelligent little mammal. More and more, humans and wildlife are crossing paths, but intentional intrusion such as the above are foolish and merit defensive action by a beneficial species.

Check out my article, Beavers in the House, in BoysQuest Magazine, April, 2015, about Dorothy Richards, who helped repopulate the Adirondacks.