Texas ebony anacua woodlands are one of the rarest native plant communities in existence in the United States. Texas ebony-anacua woodlands once grew along the banks of resacas or former river channels throughout the Rio Grande delta. During the 20th century, most of this wild and tangled habitat was cleared for agricultural or urban development.
These subtropical woodlands support a diverse natural environment that occurs nowhere else in the country.
At Resaca de La Palma State Park, just five miles west of Brownsville, trails wind through wild and tangled Texas ebony-anacua woodlands to the resaca. Resaca de la Palma State Park is the largest of three state parks belonging to the World Birding Center (WBC) network of sites.
In 2006 Texas Parks and Wildlife in cooperation with other local and federal land management agencies organized to preserve this piece of wilderness. These groups worked to remove invasive plant species and build water control structures. Today, park staff keeps wildlife in mind and controls water levels in order to mimic historic flooding. The park opened to the public in December 2008.
Long before humans came to control its flow, the Rio Grande was shaping Resaca de la Palma. In the spring and fall, the mighty river spilled over its banks and ran across different channels. The seasonal flooding matched upriver snowmelt and incoming tropical storms. Once the waters receded, those seasonal channels no longer connected to the Rio Grande and became long narrow lakes. An aerial map of the surrounding area around Brownsville shows many of these squiggly, u-shaped bodies of water, known locally as resacas. In other areas they may be called oxbow lakes. However, over time this cycle of flooding and drying changed due to human agriculture and urban development. Many resacas were no longer fed by the Rio Grande even during the wet seasons. This negatively affected the wildlife they once supported.
The park is home to yellow-billed cuckoos, Altamira orioles, groove-billed anis, caracaras and green, ringed, and belted kingfishers, black-bellied whistling ducks, green jays, great kiskadees, long-billed thrashers, great blue herons, buff-bellied hummingbirds, little blue herons, olive sparrows, white-eyed vireos, mottled ducks, blue-winged teals, northern shovelers, northern pintails, armadillos, southern yellow bats, black-spotted newts, the Rio Grande lesser siren, zebra long wing and Mexican bluewing (and many other) butterflies, bobcats, coyotes and even feral hogs.
I heard the most amazing bird song as I strolled through the Mexican Olive Trees with their large oval velvety leaves (and in the spring, huge creamy white blooms), Thorny Hackberries with their tangerine-colored gems, Ebony trees with braided bark and twisting limbs, lobed leaves and heavy shade, as well as Anacua, and some plants taller than me with floofy long fronds and unexpected yellow flowers in clusters at the top, and so many more unique trees, shrubs,and plants! And so many voices even in the middle of a blazing hot 110 degree afternoon! A lovely Band-Celled Sister Butterfly, only present in the U.S. in South Texas, flitted by my feet. A bit farther down, a bright orange Soldier butterfly flew over my head and I detected the border edging of its wings, dark brown with tiny dots. I rode my bike along the tram path over several miles, stopping to walk the trails that abutted the path every here and there.
On one such path, I arrived at the resaca, startling two bright orange Altamira Orioles who flew onto high branches of a tree, paused, seemingly blinking at me, then flew deep within. I then heard a sloshing about in the muddy waters and within the marsh I saw a dark, heavy figure, a feral hog! I believe they are invasive, but nonetheless an honor to see him! He was moving around the edge of a little island in the water when I detected a second figure laying down in the mud! They seemed unaware of my presence or perhaps undisturbed. After the Dad came all the way around and hung out in the open waters a bit, he then turned the curve, and suddenly one-two-three-four five piglets emerged, then six-seven-eight-nine ten more! Adorable! The dad took them deeper into the brush while somehow the mom emerged and loped into the open water. Two White-faced Ibises and a Great Heron looked on at the other edge of the muddy pool and seemed much more aware of me as well as of the hog and wary of both. I took a step forward to continue on the path and unfortunately the mom panicked and ran as fast as she could back into the brush startling the birds who both leaped into flight! I felt terrible frightening them in their own homes and turned back on the path. I am here to learn, but in the most respectful way possible. I thanked them for allowing me to share in such an intimate family moment.
River Deltas have sustained humans and wildlife for thousands of years. Flooding along the Rio Grande created rich delta soils which once supported a tapestry of different subtropical habitats and wildlife communities. In recent times; flood control and water diversion projects along the Rio Grande have greatly reduced the river’s natural flow and delta soils are no longer being replenished.
The Rio Grande delta is one of the most biologically diverse regions in all of North America – and one of the most threatened. More species of birds, mammals, reptiles and insects live in the Rio Grande delta than almost anywhere else in the nation. The combination of climate, geology and vegetation found in South Texas is unlike that in any other region in the United States and creates an optimal environment for many wildlife species.
Unfortunately, the future existence of species such as the ocelot and the lower Rio Grande siren is threatened by widespread destruction of native habitat in the Rio Grande delta. According to the non-profit, Defenders of Wildlife, “There are fewer than 100 ocelots remaining in Texas. Their range once extended throughout the Southwest but now only two small breeding populations remain in South Texas.
The biggest threat to ocelots is the loss of habitat from expanding development. Roads present a particular hazard, as car strikes are the leading known cause of death of ocelots in Texas. They also face significant disturbance and destruction of their habitat from industrial development like the SpaceX experimental launch site at Boca Chica and liquid natural gas export facilities along the Gulf Coast.” Another major threat to ocelots, jaguars, and jaguarundi is the fragmentation of their habitat that has resulted from the construction of the border wall. They need continuous habitat to maintain genetic diversity and robustness (not to inbreed) as well as to search for food, water, and shelter resources.
**Large portions of this blog are taken directly from Resaca De La Palma educational resources placards along the trails of the park.
