BirdAnalyst
Bird Conservation Region 36

Tamaulipan Brushlands

An ecological region spanning Texas, with 28 survey routes. BCRs are the natural unit for bird trends.

What Is Moving HereNotable signalsLong-arc shifts the engine flags automatically — sustained declines or increases large enough to stand out from year-to-year noise.Full methodology →

long arc declinecomputed indexTrend sourceWhether the figure is our own computed route-weighted index or an official USGS modeled estimate. The current build labels every trend as computed.Full methodology →

Scaled Quail has collapsed in Tamaulipan Brushlands: down 95% on the route-weighted index since 1969.

long arc increasecomputed indexTrend sourceWhether the figure is our own computed route-weighted index or an official USGS modeled estimate. The current build labels every trend as computed.Full methodology →

European Starling has surged in Tamaulipan Brushlands: up 36× on the route-weighted index since 1970.

long arc declinecomputed indexTrend sourceWhether the figure is our own computed route-weighted index or an official USGS modeled estimate. The current build labels every trend as computed.Full methodology →

Black-throated Sparrow has collapsed in Tamaulipan Brushlands: down 94% on the route-weighted index since 1969.

long arc increasecomputed indexTrend sourceWhether the figure is our own computed route-weighted index or an official USGS modeled estimate. The current build labels every trend as computed.Full methodology →

Western Kingbird has surged in Tamaulipan Brushlands: up 24× on the route-weighted index since 1971.

long arc declinecomputed indexTrend sourceWhether the figure is our own computed route-weighted index or an official USGS modeled estimate. The current build labels every trend as computed.Full methodology →

Common Gallinule has collapsed in Tamaulipan Brushlands: down 92% on the route-weighted index since 1970.

long arc increasecomputed indexTrend sourceWhether the figure is our own computed route-weighted index or an official USGS modeled estimate. The current build labels every trend as computed.Full methodology →

Eurasian Collared-Dove has surged in Tamaulipan Brushlands: up 18× on the route-weighted index since 2002.

How Guilds Are FaringGuild trendA mean-index aggregate across the species in this group — the structural direction of the guild, with individual-species noise smoothed out.Full methodology →

-85%

Arid-land birds

6 species
-71%

Shorebirds

2 species
-66%

Wetland birds

17 species
-65%

Game birds

3 species
-58%

Generalists

15 species
-51%

Forest birds

28 species
-44%

Grassland birds

7 species
-31%

Aerial insectivores

21 species
+7%

Birds of prey

13 species
+96%

Waterfowl

4 species

Survey Routes

Species By FamilyTrendPercent change in the route-weighted abundance index between a smoothed baseline window and the most recent one. It tracks direction, not absolute population.Full methodology →

Hawks, Eagles & Kites Accipitridae

Cooper's Hawk -23%Harris's Hawk -58%Red-shouldered Hawk +47%Red-tailed Hawk +11%Swainson's Hawk -41%White-tailed Hawk -26%White-tailed Kite +7%

Larks Alaudidae

Horned Lark +154%

Ducks, Geese & Waterfowl Anatidae

Black-bellied Whistling-Duck +217%Fulvous Whistling-Duck -23%Mexican Duck +2%Mottled Duck -41%

Swifts Apodidae

Chimney Swift -40%

Herons, Egrets & Bitterns Ardeidae

Great Blue Heron -19%Great Egret +23%Green Heron -3%Little Blue Heron -29%Snowy Egret +7%Tricolored Heron -26%Western Cattle-Egret -27%

Nightjars & Nighthawks Caprimulgidae

Common Nighthawk -82%Common Pauraque -74%Common Poorwill -89%Lesser Nighthawk -54%

Cardinals & Grosbeaks Cardinalidae

Blue Grosbeak -21%Dickcissel -2%Indigo Bunting -64%Northern Cardinal +7%Painted Bunting -30%Pyrrhuloxia -85%Summer Tanager -27%

New World Vultures Cathartidae

Black Vulture +587%Turkey Vulture -6%

Plovers & Lapwings Charadriidae

Killdeer -68%

Pigeons & Doves Columbidae

Common Ground Dove -40%Eurasian Collared-Dove 18×Inca Dove -9%Mourning Dove -10%Rock Pigeon -61%White-tipped Dove +672%White-winged Dove +334%

Crows, Jays & Magpies Corvidae

Chihuahuan Raven -90%Green Jay +877%

Cuckoos, Roadrunners & Anis Cuculidae

Greater Roadrunner +6%Groove-billed Ani -52%Yellow-billed Cuckoo +16%

Falcons & Caracaras Falconidae

American Kestrel +1%Crested Caracara +497%

Finches Fringillidae

House Finch +818%Lesser Goldfinch +187%

Swallows & Martins Hirundinidae

Bank Swallow -86%Barn Swallow -31%Cave Swallow +2%Cliff Swallow -84%Northern Rough-winged Swallow -56%Purple Martin +142%

Blackbirds & Orioles Icteridae

Audubon's Oriole 13×Bronzed Cowbird -20%Brown-headed Cowbird -51%Bullock's Oriole +64%Common Grackle -84%Eastern Meadowlark -43%Great-tailed Grackle -47%Hooded Oriole +984%Orchard Oriole -68%Red-winged Blackbird -55%

Yellow-breasted Chat Icteriidae

Yellow-breasted Chat +169%

Shrikes Laniidae

Loggerhead Shrike +277%

Gulls, Terns & Skimmers Laridae

Gull-billed Tern +13%Laughing Gull -19%

Mockingbirds & Thrashers Mimidae

Curve-billed Thrasher -75%Long-billed Thrasher +707%Northern Mockingbird -47%

New World Quail Odontophoridae

Northern Bobwhite -62%Scaled Quail -95%

Chickadees & Titmice Paridae

Black-crested Titmouse +385%

Wood-Warblers Parulidae

Common Yellowthroat +62%

New World Sparrows Passerellidae

Black-throated Sparrow -94%Cassin's Sparrow -54%Field Sparrow -35%Grasshopper Sparrow -81%Lark Sparrow -22%Olive Sparrow +725%

Old World Sparrows Passeridae

House Sparrow -87%

Cormorants Phalacrocoracidae

Neotropic Cormorant -50%

Pheasants, Grouse & Turkeys Phasianidae

Wild Turkey +68%

Woodpeckers Picidae

Golden-fronted Woodpecker -50%Ladder-backed Woodpecker +95%

Grebes Podicipedidae

Least Grebe -72%Pied-billed Grebe -70%

Gnatcatchers Polioptilidae

Black-tailed Gnatcatcher +105%Blue-gray Gnatcatcher +195%

Rails, Gallinules & Coots Rallidae

American Coot -34%Common Gallinule -92%

Avocets & Stilts Recurvirostridae

Black-necked Stilt +109%

Penduline Tits Remizidae

Verdin -81%

Owls Strigidae

Eastern Screech-Owl -85%Great Horned Owl -77%

Starlings & Mynas Sturnidae

European Starling 36×

Ibises & Spoonbills Threskiornithidae

White-faced Ibis +7%

Hummingbirds Trochilidae

Black-chinned Hummingbird +65%

Wrens Troglodytidae

Bewick's Wren +12%Cactus Wren -59%Carolina Wren +70%

Tyrant Flycatchers Tyrannidae

Ash-throated Flycatcher +114%Brown-crested Flycatcher +23%Couch's Kingbird +509%Eastern Kingbird -28%Eastern Phoebe +42%Great Crested Flycatcher -45%Great Kiskadee +76%Scissor-tailed Flycatcher -16%Vermilion Flycatcher +407%Western Kingbird 24×

Vireos Vireonidae

Bell's Vireo -76%White-eyed Vireo +280%

Source: USGS North American Breeding Bird Survey, retrieved 2026-05-22.