Blogs posted from this ecoregion:
The ecoregion is exclusive to the state of Texas.
Adjacent ecoregions include the following: i) the eastern half of the northern border blends into the Central Forest-Grasslands Transition (NA0804); ii) to the east we find the Texas Blackland Prairies (NA0814); iii) the south is bordered by the Tamaulipan Mezquital (NA1312); iv) to the west is the Chihuahuan Desert (NA1303); and finally, v) to the northwest are the Central and Southern Mixed Grasslands (NA0803).
Description of the Ecoregion
The ecoregion was described in the WWF publication “Terrestrial ecoregions of North America” (Ricketts, et al., 1999); essentially the same text can be found on-line at WWF’s site: www.worldwildlife.org. The map above is a screen shot from WWF’s Wildfinder site, now offline. There may also be additional information to be found on this ecoregion’s page at Wikipedia or at other sites.
Briefly, the ecoregion is more or less equivalent to the “Texas Hill Country”, and occurs on the uplifted limestone Edwards Plateau. It is distinguished from adjacent ecoregions by its distinctive mollisols, and a vegetation that was originally juniper-oak savanna and mesquite-Acacia savanna, underlain by mid- to short grasslands.
The ecoregion has been highly impacted, with at least 90% of the ecoregion converted to urban or agricultural areas. Suppression of fire and grazing by native animals has resulted in many areas in a proliferation of dense shrubby juniper-oak. Only small patches of original habitat remain; one of the largest is the Balcones Canyonlands National Wildlife Refuge near Austin, TX.
Birds of the Ecoregion
The avifauna of the ecoregion is relatively rich and according to WWF is among the top ten North American ecoregions for number of bird species. Lockwood’s checklist of the Plateau (see below) includes 431 species and my list below of characteristic species includes 276 species.
When looking at bird distribution ranges relative to this ecoregion, the ecoregion generally appeared to be well defined with respect to birds, ranges of many species corresponding well to the ecoregion limits. The ecoregion extends in a small point down to the US/Mexican border, jutting into a thin band along the Rio Grande Valley; excluding this tiny part of the ecoregion would eliminate many “borderline species” associated with the Valley and better define the avifauna of the ecoregion (for the most part I did not include these very peripheral species as “characteristic species”). Similarly, a lot of species have distribution ranges that just barely cross into the northeastern corner of the ecoregion; this would suggest that for birds anyway, the ecoregion could be better defined by reducing its extension to the northeast.
Within the US, this ecoregion offers the best opportunities for seeing two rare and endangered species. Golden-cheeked Warbler (Setophaga chrysoparia) nests in mature oak-juniper savannas of the plateau and is a near endemic in the breeding season, only spilling over slightly into adjacent ecoregions. In July 2015 I blogged about this species and this ecoregion. The Black-capped Vireo (Vireo atricapilla) breeds all through the ecoregion as well as a bit northward into the Central Forest/Grassland Transition Zone ecoregion and southward into several Mexican ecoregions of the Sierra Madre Oriental just south of the border.
Resources for the Ecoregion Birder
Without any pretence to completeness, the following resources have caught my attention and would be of value to the birder traveling to this ecoregion:
- Lockwood, Mark W., 2001. Birds of the Texas Hill County. University of Texas Press, Austin, TX.
- Lockwood, Mark W., 2008. Birds of the Edward Plateau: a field checklist. Third edition. Available at http://tpwd.texas.gov/publications/pwdpubs/media/pwd_bk_p4000_0667.pdf.
List of Characteristic Bird Species of the Ecoregion
My list below of the “characteristic species” of the ecoregion (see a more detailed explanation on the About page) are those that regularly occur in the ecoregion and thus excludes very rare or accidental species. The species are classed as residents (r), summer breeders (s), migrants (m), wintering (w), or peripheral (x), that is, occurring in the ecoregion but only on its periphery and more characteristic of an adjacent ecoregion. The peripheral species are not included in the ecoregion total.
- Black-bellied Whistling-Duck r
- Greater White-fronted Goose w
- Snow Goose w
- Ross’s Goose m
- Cackling Goose m
- Canada Goose w
- Wood Duck r
- Gadwall w
- American Wigeon w
- Mallard w
- Blue-winged Teal m
- Cinnamon Teal w
- Northern Shoveler w
- Northern Pintail w
- Green-winged Teal w
- Canvasback w
- Redhead w
- Ring-necked Duck w
- Lesser Scaup w
- Bufflehead w
- Common Goldeneye w
- Hooded Merganser w
- Ruddy Duck w
- Scaled Quail r
- Northern Bobwhite r
- Montezuma Quail r
- Wild Turkey r
- Common Loon w
- Pied-billed Grebe r
- Horned Grebe x
- Eared Grebe w
- Western Grebe w
- Neotropic Cormorant s
- Double-crested Cormorant w
- American White Pelican w
- American Bittern m
- Least Bittern m
- Great Blue Heron r
- Great Egret m
- Snowy Egret m
- Cattle Egret s
- Green Heron s
- Black-crowned Night-Heron s
- Yellow-crowned Night-Heron s
- White-faced Ibis m
- Black Vulture r
- Turkey Vulture r
- Osprey w
- Mississippi Kite m
- Bald Eagle w
- Northern Harrier w
- Sharp-shinned Hawk w
- Cooper’s Hawk w
- Red-shouldered Hawk r
- Broad-winged Hawk m
- Swainson’s Hawk s
- Zone-tailed Hawk s
- Red-tailed Hawk r
- Ferruginous Hawk w
- Golden Eagle w
- Virginia Rail m
- Sora w
- Common Gallinule s
- American Coot r
- Sandhill Crane w
- Black-necked Stilt s
- American Avocet m
- Black-bellied Plover m
- American Golden-Plover m
- Semipalmated Plover m
- Killdeer r
- Mountain Plover w
- Spotted Sandpiper w
- Solitary Sandpiper m
- Greater Yellowlegs w
- Willet m
- Lesser Yellowlegs m
- Upland Sandpiper m
- Long-billed Curlew m
- Hudsonian Godwit m
- Marbled Godwit m
- Stilt Sandpiper m
- Sanderling m
- Baird’s Sandpiper m
- Least Sandpiper w
- White-rumped Sandpiper m
- Buff-breasted Sandpiper m
- Pectoral Sandpiper m
- Semipalmated Sandpiper m
- Western Sandpiper m
- Short-billed Dowitcher m
- Long-billed Dowitcher w
- Wilson’s Snipe w
- American Woodcock x
- Wilson’s Phalarope m
- Red-necked Phalarope m
- Bonaparte’s Gull w
- Franklin’s Gull m
- Ring-billed Gull w
- Herring Gull w
- Least Tern x
- Caspian Tern m
- Black Tern m
- Common Tern m
- Forster’s Tern m
- Rock Pigeon r
- Eurasian Collared-Dove r
- Inca Dove r
- Common Ground-Dove r
- White-winged Dove r
- Mourning Dove r
- Yellow-billed Cuckoo s
- Black-billed Cuckoo m
- Greater Roadrunner r
- Groove-billed Ani x
- Barn Owl r
- Eastern Screech-Owl r
- Great Horned Owl r
- Burrowing Owl w
- Barred Owl r
- Short-eared Owl w
- Lesser Nighthawk s
- Common Nighthawk s
- Common Poorwill s
- Chuck-will’s-widow s
- Chimney Swift s
- Ruby-throated Hummingbird m
- Black-chinned Hummingbird s
- Rufous Hummingbird m
- Belted Kingfisher r
- Green Kingfisher r
- Red-headed Woodpecker w
- Golden-fronted Woodpecker r
- Red-bellied Woodpecker r
- Yellow-bellied Sapsucker w
- Ladder-backed Woodpecker r
- Downy Woodpecker r
- Hairy Woodpecker x
- Northern Flicker w
- Crested Caracara r
- American Kestrel w
- Merlin w
- Peregrine Falcon m
- Prairie Falcon w
- Olive-sided Flycatcher m
- Eastern Wood-Pewee s
- Acadian Flycatcher s
- Willow Flycatcher m
- Least Flycatcher m
- Black Phoebe r
- Eastern Phoebe w
- Say’s Phoebe w
- Vermilion Flycatcher s
- Ash-throated Flycatcher s
- Great Crested Flycatcher s
- Brown-crested Flycatcher x
- Couch’s Kingbird x
- Western Kingbird s
- Eastern Kingbird m
- Scissor-tailed Flycatcher s
- Loggerhead Shrike r
- White-eyed Vireo s
- Bell’s Vireo s
- Black-capped Vireo s
- Gray Vireo s
- Yellow-throated Vireo s
- Blue-headed Vireo w
- Hutton’s Vireo r
- Warbling Vireo m
- Red-eyed Vireo s
- Blue Jay r
- Western Scrub-Jay r
- American Crow w
- Chihuahuan Raven m
- Common Raven r
- Horned Lark r
- Purple Martin s
- Tree Swallow m
- Northern Rough-winged Swallow s
- Bank Swallow m
- Cliff Swallow s
- Cave Swallow s
- Barn Swallow s
- Carolina Chickadee r
- Black-crested Titmouse r
- Verdin r
- Bushtit r
- Red-breasted Nuthatch w
- Brown Creeper w
- Rock Wren r
- Canyon Wren r
- House Wren w
- Sedge Wren w
- Marsh Wren w
- Carolina Wren r
- Bewick’s Wren r
- Cactus Wren r
- Blue-gray Gnatcatcher s
- Black-tailed Gnatcatcher x
- Golden-crowned Kinglet w
- Ruby-crowned Kinglet w
- Eastern Bluebird r
- Swainson’s Thrush m
- Hermit Thrush w
- American Robin r
- Gray Catbird m
- Curve-billed Thrasher r
- Brown Thrasher w
- Northern Mockingbird r
- European Starling r
- American Pipit w
- Sprague’s Pipit w
- Cedar Waxwing w
- Lapland Longspur x
- Chestnut-collared Longspur w
- Smith’s Longspur x
- Ovenbird m
- Louisiana Waterthrush s
- Northern Waterthrush m
- Black-and-white Warbler s
- Prothonotary Warbler x
- Orange-crowned Warbler w
- Nashville Warbler m
- Mourning Warbler x
- Common Yellowthroat w
- American Redstart m
- Northern Parula s
- Blackburnian Warbler x
- Yellow Warbler m
- Yellow-rumped Warbler w
- Yellow-throated Warbler s
- Golden-cheeked Warbler s
- Black-throated Green Warbler m
- Wilson’s Warbler m
- Yellow-breasted Chat s
- Green-tailed Towhee w
- Spotted Towhee w
- Rufous-crowned Sparrow r
- Canyon Towhee r
- Cassin’s Sparrow r
- Chipping Sparrow r
- Clay-colored Sparrow m
- Field Sparrow r
- Vesper Sparrow w
- Lark Sparrow r
- Black-throated Sparrow r
- Lark Bunting w
- Savannah Sparrow w
- Grasshopper Sparrow r
- Le Conte’s Sparrow w
- Fox Sparrow w
- Song Sparrow w
- Lincoln’s Sparrow w
- Swamp Sparrow w
- White-throated Sparrow w
- Harris’s Sparrow w
- White-crowned Sparrow w
- Dark-eyed Junco w
- Summer Tanager s
- Western Tanager m
- Northern Cardinal r
- Pyrrhuloxia r
- Rose-breasted Grosbeak m
- Black-headed Grosbeak m
- Blue Grosbeak s
- Indigo Bunting s
- Varied Bunting s
- Painted Bunting s
- Dickcissel s
- Red-winged Blackbird r
- Eastern Meadowlark r
- Western Meadowlark r
- Yellow-headed Blackbird m
- Brewer’s Blackbird w
- Common Grackle w
- Great-tailed Grackle r
- Bronzed Cowbird s
- Brown-headed Cowbird r
- Orchard Oriole s
- Hooded Oriole s
- Bullock’s Oriole s
- Audubon’s Oriole r
- Baltimore Oriole m
- Scott’s Oriole s
- House Finch r
- Pine Siskin w
- Lesser Goldfinch s
- American Goldfinch w
- House Sparrow r
Summer breeders (s) 53
Resident breeders (r) 71
Migrants (m) 65
Wintering (w) 87
Peripheral (x) [not in Total] 13
TOTAL 276
DJG: 40 spp. (July 11, 2015)