This afternoon was spent doing a rapid appraisal of the habitat at St. Edwards Park, slightly west of Austin (Spicewood Springs Road, about two miles west of Loop 360). Heavy rain last night had left the trails muddy and wet. Walking around in the cloudy humid afternoon was not much fun. But the recent rains have been good for our vegetation. The lush green we’re seeing everywhere right now is a welcome change from the dreary brown of last winter. Perhaps our drought has really ended.
About fifty acres of diverse habitat—wetlands, grasslands and woodlands—makes St. Edwards one of the more interesting birding sites in the Austin region. For instance, on 13 May, a solitary Gray-cheeked Thrush (Catharus minimus) was reported here (and another presumably different individual also found at Hornsby Bend.) It was a rare sighting for our area, the bird’s migration (between northern South America and northern Canada) generally taking place along routes much further east. Trevon Fuller was with me today; we didn’t see any thrushes but we saw a lot of warblers that we couldn’t identify to our satisfaction—among birds, we found nothing more exotic than a very loud Green Heron (Butorides striatus). It is a beautiful bird.
Nevertheless the wildlife at St. Edwards was quite amazing. There were rabbits and signs of deer. The most astonishing phenomenon consisted of swarms of juvenile frogs—literally hundreds of them—migrating across trails, jumping like insects and smaller than many of the beetles on the forest floor. Dragonflies and damselflies, as well as an assortment of large butterflies accompanied us throughout our wanderings.
St. Edwards is easily the most diverse park I’ve so far seen in the city. It is unfortunately obviously not a well-kept secret. This afternoon we shared the area with only one other person. But there were beer cans and other trash around the creek, and plenty of horse hoof prints along the trails. The park actually consists of two parts, one a city park and one part of a preserve. Bull Creek meanders through the center dividing the two parts. The part south of Bull Creek belongs to the City of Austin Parks system. The part north of Bull Creek is in the Balcones Canyonland Preserve (BCP) and operates under the somewhat more stringent rules—I will have more on that below.
The natural habitat differences between the two sides of Bull Creek is quite amazing. The southern part contains some pockets of prairies and a fair amount of river bottom habitat. Encroachment by Ashe junipers (Juniperus ashei) is reducing the area of remaining prairie, as elsewhere in this region. Wildflowers dominated the prairie--Engelmann Daisy (Engelmannia peristenia), Indian Blanket (Gaillardia pulchella), Texas Bluebonnet (Lupinus texensis), Mexican Hat (Ratibida columnaris), Elderberry (Sambucus nigra), White Horse Nettle (Solanum elaeagnifolium), and at least ten other species we could not identify. (I am increasingly finding out that the few wildflower identification guides that Texas has are not particularly useful, at least for this area.)
The northern part rises above the southern portion and consists mostly of rocky slopes covered in Cedar and Oak. Fairly high karst cliffs greet Bull Creek which has been partly dammed in close to the western perimeter of the park. The deep pool that this has created was full of fish and aquatic insects. The terrain here is not dissimilar to the Wild Basin Wilderness Preserve which we saw earlier this month. Though the habitat is obviously less disturbed in the north, the animal life did not seem as profuse as in the southern part. But we hardly explored it.
BCP is a rather unique conservation effort in Travis County, but one that can be usefully mimicked elsewhere. It consists of more than 24 000 acres and its main purpose is to protect our endangered species and their habitat. One unique feature about it the BCP is that it a multi-agency conservation effort which operates under a permit from the U. S. Fish and Wildlife Service (USFW). This permit was issued to the BCP's two managing partners, the City of Austin and Travis County, but several other organizations own and manage units within the BCP, including Travis Audubon Society, the Lower Colorado River Authority, The Nature Conservancy, as well as numerous private land owners. Efforts by government agencies, NGOs, and private interests are relatively seamlessly integrated.
The chief goal of the BCP is to conserve eight endangered species, two of which are migratory songbirds (the Golden-cheeked Warbler—Dendroica chrysoparia, and the Black-capped Vireo—Vireo atricapillus) and six karst invertebrates (the Tooth Cave Pseudoscorpion—Tartarocreagris texana, the Tooth Cave Spider—Neoleptoneta myopica, the Tooth Cave Ground Beetle—Rhadine persephone, the Kretschmarr Cave Mold Beetle—Texamaurops reddelli, the Bone Cave Harvestman—Texella reyesi, and the Bee Creek Cave Harvestman—Texella reddelli). However, an additional twenty-seven "species of concern" include threatened plants and invertebrates to be protected. Another unique feature of BCP is that the emphasis is on habitat conservation as a whole, not just the interests of a particular species. The main problem is that the units that jointly comprise BCP are spread out over Travis County often separated by land undergoing rampant development. What we really need is a comprehensive plan for the landscape which includes management of these intervening habitats so that the ill effect of fragmentation can—at least to some extent—be mitigated.