The Austin Circle

Centered at McKinney Falls State Park, the Austin CBC Circle is situated near one of the sharpest biological transition zones in North America: The Balcones Fault.  The count circle, which ranges from roughly Brodie Lane on the western edge to Linden Road on the east, and Manor Road in the north to Creedmoor in the south, includes just a hint of the juniper-clad habitats west of the fault zone but the Austin urban area has long been known to be a blend area where “East meets West” with both Red-bellied and Golden-fronted Woodpeckers, Blue Jays and Western Scrub Jays and so forth.

Perhaps three-fourths of the circle was originally prairie and oak savanna with heavily wooded riparian corridors.  As Austin grew, the prairies gave way to agriculture and suburbs and the entire area became more wooded.  As it gets tougher to find such species as Short-eared Owls and longspurs, we encounter new residents such as White-winged and Eurasian Collared-Doves.  The addition of many more permanent water sources such as Lady Bird Lake and Hornsby Bend has enriched the area for waterfowl and shorebirds even as urbanization changed the abundance of other species.

The concerted efforts of the City of Austin and Travis County to protect open space and important habitats in such areas as the Barton Creek Wilderness Park, the Colorado River Metro Park, and Onion Creek Nature Preserve provide some counter-balance to the loss of native habitat to roads, subdivisions, and commercial development along the I-35 corridor and the newer Toll Roads which dissect the count circle.  With climate change, we anticipate that the Austin CBC Circle will provide an important window to species responses within our cross-section of diverse habitats.  Will Purple Finches ever be seen in numbers again?  Will Hutton’s Vireos and Long-billed Thrashers become as routine as Couch’s Kingbirds and Ringed Kingfishers?  Time--and the Austin CBC--will tell.

Chuck Sexton