by Dr. George Yatskievych (Botanist and Curator, Billie L. Turner Plant Resources Center) and Dr. Dean Hendrickson (Curator of Ichthyology)
The road to Candelaria, Texas is long and dusty, but well worth the drive. Candelaria is located on the Rio Grande in Presidio County. Rancho Pensado, headquartered in this tiny community, is noted for its sweetwater springs and the stark beauty of its landscape. Our host here was ranch owner / retired veterinarian, Dr. Harry Miller, whose son (also Harry Miller) owns the adjacent Circle Dug Ranch. We were here primarily to investigate the aquatic fauna, especially the fishes, but also the spring-blooming flora.
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| Setting up a seine on a channel of Capote Creek (photo: Ron George) |
The landscape of this area undulates upward from the river toward the adjacent Sierra Vieja, with numerous hoodoos (columns or pinnacles of weathered rock) and other geological features. Capote Canyon has the tallest waterfall in Texas in the mountains just above the ranch, and is the largest watershed on the property. It has long reaches of temporary surface water, and when we set out to start our research, we hoped to find some hidden permanent springs and seeps.
The rains had been sparse this spring, causing the air to become dusty as we traveled the bumpy, unpaved ranch roads to reach our study sites. This portion of the Chihuahuan Desert is rich in cacti, including lots of prickly pears (Opuntia) and several uncommon plants of conservation concern. Nearly every plant has thorns or spines, thick, small leaves, or other adaptations to retard water loss and impede herbivorous insects and mammals. The principal shrubs are mesquites, acacias, and creosote bush, but numerous other woody plants occur widely-spaced in the scrubby vegetation, except along the river and in protected drainages.
One unusual area in the southern portion of the property is a saline ciénega (Spanish for marshes of North America’s arid areas).
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| Sample of fishes collected in the Capote Creek on the Candelaria Ranch (photo: Ron George) |
This particular one is spring-fed with highly saline water, and while clearly having been once much larger, there are still expansive broad flats with saturated soils surrounded by salt crusts and with islands of grassy vegetation. The abrupt transition from this wetland to the surrounding desert slopes is remarkable. The number of species able to survive in the hypersaline seepage environment is relatively few, and these mostly do not occur elsewhere, even in other non-saline wetlands.
Once common and extensive, ciénegas are now relatively rare in most parts of the North American deserts, and the remaining remnants are important habitats for now rare flora and fauna. West Texas has a number of rare fishes known only from springs and ciénegas (Balmorhea State Park is probably the most known area for them), and we hoped we might find new populations of one or more of those in this large, previously almost un-sampled (for fishes anyway) area.
Unfortunately, we found only a few common fish species, likely introduced to the artificial impoundments built to store water for livestock. But, these combined ranches are huge, and we barely scratched their surface. We didn’t get to some particularly intriguing, remote and rugged canyons, and time limited our ability to sample fishes in the long-forgotten reach of the Río Grande – the only samples from there are few, and the last collected 30 years ago. We’re anxious to return, hopefully with others from the Biodiversity Center, and in other seasons, to more thoroughly inventory the area’s under-explored biodiversity.
