Seven Bluff Birding and other Wildlife
Roger Tory Peterson describes the ecological belt dividing eastern and western North American species as the Ecological Twilight Zone. Seven Bluff sits at the southern tail of this divide; a crossroads for both regions. In addition, this area is enriched with species from the Rio Grande Valley, Mexico, lower and central coasts. The geology of the area provides upland habitat, waterways, and is another conversion from arid regions into more mesic ecosystems. Perhaps this is why Texas was the first state to have its own field guide!
Seven Bluff Cabins is set in a chemical-free pecan orchard in the Frio River Canyon with river frontage making it a superb bird-watching venue. The area is covered in the Texas Parks and Wildlife Birds of the Edwards Plateau. Seven Bluff Cabins has a "work in progress" checklist: Seven Bluff Birds. Feel free to share your sitings with us at birding@sevenbluffscabins.com. Let us know who you are and the dates you are reporting about.
Our four-legged friends are also abundant here in the orchard. Early morning coffee and evening relaxation is shared with white-tailed and axis deer, turkey, racoon, skunk, and even red fox.
Geology of Seven Bluff
Seven Bluff is located approximately 4 miles north of the Concan Fault. It is an outcrop of the Devils River Formation overlying the Upper Glen Rose Limestone. The upper Glen Rose Limestone is composed of alternating beds of marl, shale and limestone formed in the shallow waters of a broad, prehistoric tidal flat. This ancient tidal flat supported a variety of species including dinosaurs, evidence of which can be seen in the bed of the Sabinal River about 12 miles to the east where dinosaur tracks are still preserved.
After a rise in sea levels a more open marine environment formed which resulted in the deposition of a limestone known as the Devils River Formation. This formed as a reefal trend around an area of deeper water known as the Maverick Basin. A typical fossil found in the Devils River Formation is a bivalve called pelecypod, also known as a "Caprinid" which inhabited a similar environment that today's corals now inhabit. "Caprinids" formed the primary building structure for the reefal trend. This, along with geologic faulting, creates the high permeability to the Edwards Aquifer of northern Uvalde and Medina Counties. The high porosity and permeability that occurs in the Edwards Aquifer recharge zone results in rivers and streams losing most, if not all, of their base flow to the Edwards Aquifer. Resource: Allan Clark, Geologist.
Stargazing
"I've never seen the real Milky Way before!", said one young visitor to Seven Bluff. The sky is big and the seeing is excellent here. The air is clean and there is no light pollution from any nearby cities. Many guests bring their telescopes, especially during the cool months. After the 'S' mores" are gone and the campfire is out, take your lawn chair, binoculars, and walk out into the open area beyond the orchard for the "Greatest Show NOT On Earth"! |
