Indian Bridge and its river rocks
PHOTOS BY GARRY BRANDENBURG — Migrating birds have many methods to help them navigate from northern summer homes toward winter habitats. Geographical landmarks such as river valleys are just one of the ways. River valleys tend to have forested edges or other large timber stand blocks of habitat that hold food sources during early fall. Other items known to assist birds are earth’s magnetic fields, sun angle, moon angle, and longer daylight hours as some species continue journeys to the equator or even south of the equator. What is remarkable is how year after year all kinds of birds find their way to wintering grounds and come spring, retrace their flight back northward. Today’s image of a Fox Sparrow is just one of many sparrows that will make Iowa a winter home. As for the Iowa River image, this birdseye view illustrates water for bathing and drinking, plus sandbars for probing for aquatic insects.
Sparrows are not all just another LBJ (little brown jobs) to keep us humans puzzling over nuances of identification details. However, one must pay attention to specific details to truly note the difference between these small active birds.
It can be confusing to try to learn which sparrow you have within your binocular viewpoint. Take careful mental notes of eye lines, feather colors of the head top, eye stripes, eye rings, bill shape and bill color, leg color and wing bar patterns. Chest patterns of feathers is another major item as is the color of the tail.
Twenty species of sparrows will be within Iowa during any year. Some are here for the summer only, others will come from the northern boreal forests of Canada and find Iowa a good place to spend the winter.
No need to go further south for a number of species. Song, Field and Swamp sparrows are in Iowa for the summer months, then they go south for the winter. White-throated, Le Contes and Lincolns are short time transient visitors each spring as they pass through Iowa to go much further north for their summer.
Winter time sparrows visiting and staying during our cold season will include American Tree sparrows and Dark-eyed Juncos. They find no reason to go any more south, and in this group can be found the Fox sparrow featured in today’s photo.
Most fox sparrows will over winter from central Missouri southward. However, mid January is not an uncommon time to find a fox sparrow at a backyard feeder. Note the dark reddish tail top and numerous little pointed ‘arrow-tip’ markings of its chest. Behind and below its eye is a crimson feather patch. Fox sparrows are also known for a highly variable feather marking pattern with subtle differences.
One of the easiest sparrows to identify is the Dark-eyed Junco. Iowa is as far south as some of these species need to travel, finding an Iowa winter well suited for its needs.
It does go as far south as Texas and the gulf states. Winter range could be virtually anywhere in the lower 48 states. Alaska and all of Canada are where its summer home ranges exist.
It has a characteristic dark gray to almost black head and chest, a white belly, slightly light brown sides and gray back and wings. It has a tiny white bill. Enjoy all of these winter bird visitors this fall and winter.
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Iowa River ramblings are my next topic. Today’s image shows the river looking west from the Albion old railroad bridge toward Timmons Grove.
Low flow rates all year long have easily highlighted the meandering pathway of the deeper water, which incidentally in this segment is not very deep at all. Exposed sand bars have weedy low growing vegetation growing on these exposed soils.
Water levels have been very steady at a gauge reading of 9.85 feet. Remember, the U.S. Army Corps of Engineers gauge readings are relative only and do not represent actual water column depths. The depth of water varies across the channel from a few inches to perhaps 12 inches. On average, the flow rate at this time is just a trickle compared to the potential flood event flow rates when the river level can be as much as 13.5 feet higher than the water as seen in the river now. I use 13.5 feet as an accurate measurement of the difference between low flow and the highest flow rate from July 2, 2014. On that date, our local Iowa River reached its historic highest flood recordings of modern day eras.
Have you heard of Indian Bridge? That is the locally known name for this crossing of the Iowa River. I urge you to travel upstream to this river bridge on gravel county road E-23, also known as 148th Street.
To get there, go north of Albion toward Liscomb about one mile on S-75. Turn west on 148th. Go west approximately three miles to the river bridge.
Indian Bridge received its unofficial name due the natural history of this stream segment. The river bed is rocky. With binoculars you can view the river water, and its exposed rocks, from the vantage point of this bridge.
During fall seasons of low flow, it has natural characteristics that make any fish movements through shallow water an advantage for catching fish. Old historic documents from Marshall County’s past times note how early settlers encountered Meskwaki Indians catching fish in this region to help lay up a winter food supply. A factor in why this location was successful for the Meskwaki was a geologic feature of the floodplain.
Just east of this bridge is an ancient glacial aged river bank, a terrace, now high and dry, that speaks volumes to geomorphologists about post glacial environments. This landform feature is subtle, but it is evidence of river water levels centuries ago being much larger than flow rates of today.
Water from glacial runoffs over a long period of time eroded the river channel, and thus exposed many granite boulders within the river bed. Even today, one can look upstream from Indian Bridge and see numerous boulders exposed in the river bed. This rocky bed of the river is worth trekking through to see what one can discover.
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Public lands in Marshall County are primarily county owned, the result of the County Conservation Board system that was created in 1955 by the Iowa Legislature. At the county level, land acquisitions for county parks, forests, prairie lands, and other historic or botanical
significant sites were authorized, and programs for outdoor recreation and education were part of that initial mix.
An important ingredient for any of those land gifts, and/or purchases, were the natural features of those land parcels. Scenic features, rocky terrain, low lying floodplains that frequently flooded or rich biological and botanical inventories of unique vegetation.
Over time, these parks, wildlife areas, camping sites, and botanical preserves have been recognized for their value to outdoor recreation and education. A map of all the current public lands managed by the County Conservation department is available at the Grimes Farm and Conservation Center.
That map contains a long history of careful stewardship of special places to see and explore.
When one looks carefully at the State of Iowa and its public land holdings, we can get a larger picture of the huge variety of landforms, historical and archaeological, plus numerous geologic features, and see the recreational potential each has contributed to Iowa’s diverse natural history.
In 1895, Thomas McBride, professor of natural history at the University of Iowa, envisioned a series of state parks. He worked with a colleague Louis Pammel, professor of Botany at Iowa State University, to work toward what was to become the 1917 State Park Act.
The legislation called for an inventory of natural history sites, to help conserve native plants, animals, unique trees, geological formations, Indian mounds, rare old buildings and natural lakes and rivers whereby “to show generations yet unborn what Iowa had in the way
of prairie, valley, lake and river.”
We may be familiar with common species like oak trees, white-tailed deer, cardinals, butterflies, mushrooms and garter snakes, but did you know that the full number of critters found in Iowa is huge?
Here is a partial list: 1,800 vascular plants made up of 97 tree species, 114 shrubs, 377 types of grasses and sedges, 51 ferns, and over 1,000 wildflowers. Now add 271 mosses, over 1,700 fungi, 397 birds, 149 fish, 71 mammals, 67 reptiles and amphibians, 125 butterflies, over 2,100 moths, 300 bees, 55 mosquitoes, 46 mussels, 180 snails and thousands of invertebrates and other microorganisms. These life forms live and hopefully continue to thrive within and upon all the lands of Iowa, public and to a some degree private area also.
Iowa has 56,272.81 square miles between its borders, and upon doing the math, 36,014,598 acres. State-owned lands for state parks, state wildlife management areas, state preserves, and public lakes totals about 385,000 acres — roughly one percent of Iowa’s total land area.
Now consider this fact: public right of ways for Iowa highways total over 920,000 acres, way more than is devoted to natural areas. Please take note that many county and state public land sites offer spectacular scenic and geologic features, very unsuitable for other land uses.
About one-third of public lands have a CSR (Crop Suitability Rating) of just 32. That is a long way from the mythical 100 CSR. Many of the best farmland acres for which Iowa is noted have CSR scores in the high 80s to low 90s.
Many public lands have low CSR ratings due to the very unique factors of why conservation interests value them; steep topography, wetland conditions of marshes or lakes, flood prone river bottoms with hydric soil types (high water table), or other unique soil types that, if farming was attempted, would fail due to high erosion factors. Therefore these fragile soils are best left in grass or native prairie.
The above data points will help you keep in perspective many of the myriad details that are considered when conservation oriented land uses get scrutinized. Iowa can be and is proud of its natural heritage and how the ability of our diverse soil types — derived from long geological
processes — have allowed agriculture to flourish. Careful stewardship of all land types is important.
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Aldo Leopold stated in his Round River essay, “To keep every cog and wheel is the first precaution of intelligent tinkering.”
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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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- PHOTOS BY GARRY BRANDENBURG — Migrating birds have many methods to help them navigate from northern summer homes toward winter habitats. Geographical landmarks such as river valleys are just one of the ways. River valleys tend to have forested edges or other large timber stand blocks of habitat that hold food sources during early fall. Other items known to assist birds are earth’s magnetic fields, sun angle, moon angle, and longer daylight hours as some species continue journeys to the equator or even south of the equator. What is remarkable is how year after year all kinds of birds find their way to wintering grounds and come spring, retrace their flight back northward. Today’s image of a Fox Sparrow is just one of many sparrows that will make Iowa a winter home. As for the Iowa River image, this birdseye view illustrates water for bathing and drinking, plus sandbars for probing for aquatic insects.
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