My World: Rock Bluff (Ozarks Geology)

Rock bluff along the route of a recent afternoon walk.

I usually say I live in the Ozark Mountains, but "mountain" is a generic term largely based upon appearance.  If you have hills and valleys, the combination of the two is called "mountains".  In geologic terms, it would be more correct to say I live on the Ozark Plateau because the Ozarks are actually a dissected plateau.  Most mountain ranges were formed when geologic events -- like the collision of tectonic plates -- caused the earth's crust to buckle and fold, uplifting mountains and leaving valleys between them. By contrast, the entire area known as the Ozarks (northern Arkansas, southern Missouri, a bit of eastern Oklahoma and a tiny corner of southeastern Kansas) was uplifted as a plateau with relatively little buckling and folding..  Over millions of years since the uplift, valleys eroded into the plateau leaving hills behind.  


Being a dissected plateau gives the Ozarks some unique features.  Our mountain tops tend to be flat.  The decent into valleys is rugged and steep.    The various strata of sedimentary rock deposited before the Ozark Plateau was uplifted remain in place just like they were laid down millions of years ago. There is little of the scrambling of strata that occurs when the earth's crust is folded and buckled.  Geologist can easily follow a particular rock stratum over a wide geographic area.

Overview of the Ozark Plateau and its four main regions.  (Wikipedia)

Side Note:  The origin of the name "Ozarks" is disputed.  Many think it is a linguistic corruption of  the French abbreviation aux Arks (short for aux Arkansas, or "of Arkansas" in English) which originally referred to the French trading post at Arkansas Post, but eventually came to refer to all Ozark Plateau drainage into the Arkansas and Missouri Rivers.  Other possible derivations include aux arcs meaning "of the arches" in reference to the dozens of natural bridges formed by erosion and collapsed caves in the Ozark region.  (Source:  Wikipedia)

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My World: Rock Bluff (Ozarks Geology)

Nine-Banded Armadillo (Dasypus novemcinctus)

The claws on the front feet of this critter leave little doubt it is 

well adapted for digging.

Nine-banded Armadillos live in my world -- or do I live in their world?  Neither of us is native to the Ozarks, though armadillos have inhabited the Earth much longer than humans.

The Nine-banded Armadillo's ancestors lived quite comfortably in South America until around three million years ago when the formation of the Isthmus of Panama allowed them to start moving north.  They've been heading north ever since.  Armadillos were first recorded in south Texas in the early nineteenth century.  Many researchers thought the dillers' northward migration would be severely limited by cold weather.  Armadillos have a slow metobolic rate, little fat and lack the ability to regulate their body temperatures as well as most mammals.  However, Nine-banded Armadillos proved to be much more adaptable than early researchers thought.  By 1995 the species had become well-established in Texas, Oklahoma, Louisiana, Arkansas, Mississippi, Alabama, and Florida, and had been sighted as far afield as Kansas, Missouri, Tennessee, Georgia and South Carolina. A decade later, the armadillo had become established in all of those areas and continued its migration, being sighted as far north as southern Nebraska, southern Illinois, and southern Indiana.  (There is also ample evidence humans introduced armadillos into several southern states where they thrived.) (Source:  Wikipedia)

That I was able to take these photos during the middle of the afternoon, illustrates one of the  Nine-banded Armadillos' adaptations to colder temperatures.  They are normally nocturnal, but when the weather is cold, dillers remain in their underground burrows all night and come out to forage during the warmer parts of the day.

The bands on the Nine-banded Armadillo's carapace

are the basis for its common name, but it can actually have between

7 and 11 bands.  I only count eight bands on this individual.

Armadillos are primarily insectivores.  They dig up and eat a wide variety of bugs, larvae, grubs, etc.  However, stomach content analysis has show dillers will eat pretty much any small critter that doesn't get out of their way, including small reptiles, amphibians and birds.  Their digging behavior often makes armadillos unpopular among gardeners and those dedicated to having beautiful lawns.  I have no interest in maintaining a convention lawn, but do find it exasperating when a diller "tills" a well-mulched vegetable garden bed.

A previous post shows an armadillo litter out foraging.  (Armadillo litters are always identical quadruplets.)  Other sources of more information than you ever really wanted to know about these unique critters include Mammals of Texas, Biogeography of  the Nine-Banded Armadillo and Armadillo Fact File.

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Nine-Banded Armadillo (Dasypus novemcinctus)

My World: Low Clouds Over Bear Creek Valley

(Photo:  Jo Smith on 12/13/09)

Low clouds hung around for a while early Sunday morning.

(Photo:  Jo Smith on 12/13/09)

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My World: Low Clouds Over Bear Creek Valley

A Cloudless Sulphur Butterfly (Phoebis sennae) in My World

This tattered and worn Cloudless Sulphur Butterfly on a tattered and worn zinnia flower seems an appropriate symbol for current conditions in my world. Nature is winding down for winter.

We've only had a couple of light frosts thus far, but soon a major blast of Arctic air will come barreling down from the north and all the bugs and flowers will be gone. Or will they?

While I won't see nearly as many insects until spring, they will still be here. Most will be hiding in leaf litter or underground in their larval forms. A few  will overwinter as adults and surprise me with their appearance on warm winter days. All will be waiting for spring to begin again their life cycles.

In their own way, the zinnias will also still be here. All the genetic information needed to produce new plants and flowers is stored in their tiny seeds. Were we good gardeners, we'd deadhead each flower after the bloom is spent. Were we even mediocre gardeners, we clean up all the old plants after they freeze. But if history is any guide, the dead zinnias will remain in the garden for most of the winter if not all the way into next spring. Our excuse is that the zinnias need plenty of time to reseed themselves. Also, many times I've seen Goldfinches feeding on zinnia seeds. Regardless, the zinnias are still here.

Nature will soon take a winter's rest, but insects and flowers still abound and are just waiting for spring to begin again.

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A Cloudless Sulphur Butterfly (Phoebis sennae) in My World