Big beasts — past and present

Photos by Garry Brandenburg — Bison are one of North America’s biggest and charismatic creatures of our prairie grassland heritage.It is hard to imagine the vast herds estimated to once be over 50 million animals scattered across the grassland prairies of our lower 48 states. But they did exist once upon a time....until settlement moved west and eliminated many of these mammals. Thanks to far a few far sighted people, remnant herds became the focus for conservation efforts. My images today feature a small portion of a bison herd at Fort Niobrara National Wildlife Refuge near Valentine, Nebraska. At their visitor center, a replica skull with long horn cores is on display for the extinct giant bison, Bison latifrons. And for comparison, at Green Castle is our modern day bison that local folks can go see.

BISON are big, no matter if they are the modern day species we may be familiar with, or ancient and now extinct bison relatives from times long ago. If local folks are interested in seeing living bison this option is easy. Just travel to Green Castle Recreation Area one mile south of Ferguson. Within an enclosed grassland pen, there are three bison…one adult bull and two cows. A sturdy fence keeps people out and bison in. However viewing is easy and encouraged. Bring binoculars, or if the bison happen to be close to the fence line, you may be only a few feet away from this shaggy dark brown hair covered critter. They are impressive animals, and not domesticated.

The North American bison of today is a descendant from a longer lineage of similar looking but larger bodied bison. Although we may call them buffalo, they are scientifically different than the cape buffalo of Africa or the Asian water buffalo, both of which are only distantly related to our common bison of today. When European settlers first arrived in North America, they thought the bison resembled its African or Asian counterparts. The French called the plains bison “la boeuf” meaning “ox” or “beef.” The term “bison” is actually Greek for “ox-like.” From an evolutionary standpoint, bison were animals of grassland steppes of Europe and Asia. During geologic times when glacial systems advancing and retreating multiple times, ancient bison adapted as best they could. When glacial systems were at maximums, ocean levels were much lower and these lower seas allowed a land bridge to be exposed between Siberia and Alaska. This happened more than once. Many animals were able to migrate both ways, from North America west to Asia and Asia eastward to North America. This is how ancient bison made the voyage to new lands as evidenced by archeological sites, and fossil excavations.

Bigger bodied mammals are more efficient at retaining body heat. And when glacial systems were weakening, but still not laughing matter with regard to survival, big bodies of ancient bison helped them stay alive. Our modern day smaller bison species is the ultimate survivor from the past.

There are within the fossil record several intermediary sizes of bison, all larger than our modern day species, but getting progressively smaller in body size, skull size and horn size over time. The extinct Bison latifrons, the replica that I was standing next to at Niobrara NWR, is the biggest boy of all ancient bison. The B. latifrons fiberglass replica cast was made from a fossil specimen. Latifrons became extinct about 75,000 years ago, unable to adapt this time to natural climatic shifts and recovery from the last Ice Age. Bison latifrons specimens have been found in many prairie states or Canada. The replica shows the horn cores which were true bone. Over these cores grew a layer of keratin, the shiny black surface on the outside. Tip to tip measurements have been estimated by scientists at more than 6 to nearly 10 feet.

Bison latifrons originated approximately 800,000 years ago in the early Pleistocene epoch and lived until about 75,000 years ago. Other ancient bison species of the past were able to survive longer however, they also became extinct as natural climate shifts took a firmer grip upon the Northern hemisphere. The modern day bison you can see today in many places, at ranches or National Wildlife Refuges like Niobrara or Yellowstone National Park, are big attractions.

If your summer vacation travels this year should take you west, say to Rapid City, South Dakota, make a point to visit the School of Mines and Geology Museum on the campus near downtown Rapid City. Inside you will find all kinds of ancient bison critter skulls showing many intermediary sizes of these big beasts. Some of those big bison skulls came from local ranches in South Dakota. The museum also has many skeletons of other ancient land animals, and ocean animals from the once Great Interior Seaway. Just the land animals included woolly mammoths, mastodons, camels, rhinos, ferrets, pika, snowshoe hares, giant beaver, the American lion, dire wolves and giant short-nosed bears. Ancient sea animal skeletons tell of horrific life cycles. Many fossil sites in the Dakotas have revealed big swimming lizards and ancient huge bony fishes. All are big beasts of the past.

On a much smaller scale, FROGS and TOADS will soon be talking their own language to each other as spring continues to unfold. Chorus frogs are about 1 inch long but have a voice way bigger than their body size. They are tan to pale green with stripes down their back. They like water or grasslands close to water. Gray tree frogs are common. And these amphibians can change color to help match background vegetation. They can grow to about 2 inches in length. They have sticky toes to allow them to climb and cling to all types of surfaces. The American toad is larger, has a rough skin texture and is a skilled insect eater. Life cycles of these amphibians must involve water for their eggs, then the tadpole stage without visible legs at first. Later the gills become replaces and their legs begin to grow. Legs allow these animals to use land and breathe air out of the water. Listen this spring to the sounds of frogs and toads.

BIRDS to watch for this week include Virginia rail, eastern sandpipers, common terns, eastern whip-poor-will, cliff swallows, house wrens, brown thrashers, pine siskins, grasshopper and white-throated sparrows. It is too early for ruby-throated hummingbirds. Look for them on or about May 7.

DUCKS UNLIMITED, the Iowa River Chapter, is well into the planning stages for a banquet and fund raising event for 2021. As activities get back to a more normal level, wildlife conservation organizations are eager to get their members back in sync with activities that will benefit their causes. The date for the local DU banquet will be June 12 at the Best Western Regency Inn. Doors will open at 5 p.m. with a dinner and auction at 7 p.m. Stay tuned.

Garry Brandenburg is the retired director of the Marshall County Conservation Board. He is a graduate of Iowa State University with a BS degree in Fish & Wildlife Biology.

Contact him at:

P.O. Box 96

Albion, IA 50005


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