Nature and Wildlife
The Stunning Biodiversity of the Great Bend of the Gila
The Great Bend of the Gila is a volcanic landscape that has been shaped by natural forces over millions of years. Today, it is part of the Sonoran Desert, which ranks first in biodiversity among the deserts of the U.S., and this is on full display in the Great Bend of the Gila area. It’s breathtaking to hike among these desert-adapted plants in the summer monsoon season, when ripening fruits and blooming flowers create a colorful mosaic on the desert floor.
The landscape is a mix of riparian and low desert habitat types. It is a relatively flat desert with several low mountain ranges and their associated bajadas and drainage system of washes and arroyos.
The Gila River corridor is the primary riparian zone, and large and small washes also support riparian vegetation. Away from the washes, the landscape is more sparsely vegetated with typical low desert plants such as ocotillo, palo verde, and creosote, as well as the occasional saguaro cactus or ironwood tree.
This mix of riparian and desert habitats makes the area particularly important for conservation.
The riparian areas and availability of free water support a very high number of birds, including migratory species and shorebirds. One bird list for the stretch between Arlington and Gila Bend counts over 150 species, including several species of ducks and geese, a dozen different species of hawks and falcons, a half-dozen species of warblers, and more than a dozen species of sparrows, finches, thrashers, and blackbirds. The riparian areas are also an important water source for mammals, many of which come to the river to drink.
A few of the many animals using the Great Bend of the Gila as a travel corridor, as captured on hidden trail cameras:
Away from the river, the classic low Sonoran Desert habitat supports iconic species such as Sonoran desert tortoise, Desert Bighorn sheep, and Gila monster, as well as mule deer, javelina, Kit fox, Ringtail cat, Kangaroo rat, and Mojave rattlesnake.
Of particular significance is the example of Sonoran pronghorn. This species—at one point numbering only in the teens of individuals in the U.S.—has been the focus of a robust recovery program on Cabeza Prieta National Wildlife Refuge (NWR), Organ Pipe Cactus National Monument, and the Barry M. Goldwater Gunnery Range (BMGR) south of Interstate 8. Sonoran pronghorn are especially road-averse, so a second population is being established via a captive breeding and release effort on the Kofa NWR north of I-8. The Great Bend of the Gila ecosystem is well suited to Sonoran pronghorn and well connected to Kofa, making permanent protection of the Great Bend of the Gila an important way to expand the range for this endangered species.
Banner image: Dawn Kish
The Great Bend of the Gila is home to numerous plants and animals.
The Great Bend is Sonoran Desert Ecoregion type. Two rain seasons per year—summer monsoons from the south and winter storms from the northwest—support a high diversity of vegetation, which in turn supports a high level of biodiversity generally. The presence of free water—perennially in the Gila River itself, as well as ephemerally in washes and tanks across the landscape—supports a high number of plant, animal, and particularly bird species that are atypical for desert environments (shorebirds along the river, for example). The following are incomplete listings of the species found in the area.
PLANTS
Buckhorn Cholla (Cylindropuntia acanthocarpa)
Diamond Cholla (Cylindropuntia ramosissima)
Teddy Bear Cholla (Cylindropuntia bigelovii)
Saguaro Cactus (Carnegiea giganteus)
Fishhook Pincushion (Mammalaria grahamii)
Barrel Cactus (Ferocactus cylindraceus)
Hedgehog Cactus (Echinocereus engelmannii)
Creosote Bush (Larrea tridentata)
White Bursage (Ambrosia dumosa)
Trangle-leaf Bursage(Ambrosia deltoidea)
Night-blooming Cereus (Peniocereus greggii)
Foothills Palo Verde (Cercidium microphyllum)
Blue Palo Verde (Parkinsonia florida)
Velvet Mesquite (Prosopis velutina)
Desert Willow (Chilopsis linearis)
Ironwood (Olneya tesota)
Desert Mistletoe (Phoradendron californicum)
Cat-Claw Acacia (Acacia greggiii)
Wolfberry (Lycium californicum spp.)
Chuparosa (Justicia californica )
Ocotillo (Fouquieria splendens)
Silver Cholla (Cylindropuntia echinocarpa)
Desert Christmas Cactus (Cylindropuntia leptocaulis)
White Ratany (Krameria grayi)
Bladder Sage (Salazaria mexicana)
Crucifixion Thorn (Castela emoryi)
Graythorn (Ziziphus obtusifolia)
Fremont Thorn Bush (Lycium fremontii)
California Poppy (Eschscholzia californica)
Notch-leaved Phacelia (Phacelia crenulata)
Orange Fiddleneck (Amsinckia intermedia)
Peppergrass (Lepidium lasiocarpum)
Bladderpod Mustard (Lesquerella sp.)
Whitlowgrass (Draba cuneifolia)
Allscale (Atriplex polycarpa)
Lance-leaf Ditaxis (Argythamnia lanceolata)
Big Galeta (Pleuraphis rigida)
Canyon Ragweed (Ambrosia ambrosioides)
Desert Broom (Baccharis sarothroides)
Arrow Weed (Pluchea sericea)
Desert Seepweed (Suaeda moquinii)
Quailbush (Atriplex lentiformis)
Seep Baccharis (Baccharis salicifolia)
Virgin's Bower (Clematis drummondii)
MAMMALS
Desert bighorn sheep
Sonoran pronghorn antelope
Mule deer
Javelina
Kit Fox (Vulpes macrotis)
Audubon's Cottontail
Desert Kangaroo Rat (Dipodomys deserti)
Lesser long-nosed bat
Mexican Free-tailed bat
Sonoran pronghorn. Image courtesy of the Barry M. Goldwater Range
REPTILES
Gila monster
Mojave Rattlesnake (Crotalus scutulatus)
Sonoran Whipsnake
Sonoran desert tortoise
Lowland leopard frog
BIRDS & RAPTORS
Snow Goose
Ross's Goose
Canada Goose
Wood Duck
American Wigeon
Mallard
Cinnamon Teal
Northern Shoveler
Green-winged Teal
Canvasback
Redhead
Ring-necked Duck
Lesser Scaup
White-winged Scoter
Red-breasted Merganser
Ruddy Duck
Gambel's Quail
Pied-billed Grebe
Eared Grebe
Red-necked Grebe
Clark's Grebe
Western Grebe
Neotropic Cormorant
Double-crested Cormorant
American White Pelican
Least Bittern
Great Blue Heron
Great Egret
Snowy Egret
Reddish Egret
Cattle Egret
Green Heron
Black-crowned Night-Heron
Ibises and Spoonbills
White-faced Ibis
Glossy Ibis
Roseate Spoonbill
Turkey Vulture
Osprey
White-tailed Kite
Bald Eagle
Northern Harrier
Sharp-shinned Hawk
Cooper's Hawk
Swainson's Hawk
Red-tailed Hawk
Ferruginous Hawk
American Kestrel
Merlin
Peregrine Falcon
Prairie Falcon
Great-horned Owl
Lesser Night Hawk
Clapper Rail
Virginia Rail
Sora
Common Moorhen
American Coot
Sandhill Crane
Plovers
Semipalmated Sandpiper
Killdeer
Black-necked Stilt
American Avocet
Spotted Sandpiper
Greater Yellowlegs
Lesser Yellowlegs
Long-billed Curlew
Western Sandpiper
Least Sandpiper
Long-billed Dowitcher
Wilson's Phalarope
Red-necked Phalarope
Ring-billed Gull
Herring Gull
Rock Pigeon
Eurasian Collared-Dove
White-winged Dove
Mourning Dove
Inca Dove
Common Ground-Dove
Greater Roadrunner
Great Horned Owl
Western burrowing Owl
White-throated Swift
Anna's Hummingbird
Broad-tailed Hummingbird
Costa's Hummingbird
Belted Kingfisher
Gila Woodpecker
Red-naped Sapsucker
Ladder-backed Woodpecker
Northern Flicker (Red-shafted)
Gilded Flicker
Western Wood-Pewee
Gray Flycatcher
Black Phoebe
Say's Phoebe
Vermilion Flycatcher
Ash-throated Flycatcher
Western Kingbird
Eastern Kingbird
Loggerhead Shrike
Common Raven
Horned Lark
Northern Rough-winged Swallow
Tree Swallow
Violet-green Swallow
Barn Swallow
Cliff Swallow
Verdin
Cactus Wren
Rock Wren
Bewick's Wren
House Wren
Marsh Wren
Blue-gray Gnatcatcher
Black-tailed Gnatcatcher
Ruby-crowned Kinglet
Western Bluebird
Mountain Bluebird
Northern Mockingbird
Sage Thrasher
Bendire's Thrasher
Curve-billed Thrasher
Crissal Thrasher
Le Conte's Thrasher
European Starling
American Pipit
Phainopepla
Orange-crowned Warbler
Yellow Warbler
Yellow-rumped Warbler
Townsend's Warbler
Common Yellowthroat
Wilson's Warbler
Abert's Towhee
Brewer's Sparrow
Vesper Sparrow
Lark Sparrow
Black-throated Sparrow
Sage Sparrow
Grasshopper Sparrow
Savannah Sparrow
Song Sparrow
Lincoln's Sparrow
Swamp Sparrow
Lark Bunting
White-crowned Sparrow
Dark-eyed Junco
Northern Cardinal
Black-headed Grosbeak
Blue Grosbeak
Red-winged Blackbird
Eastern Meadowlark
Western Meadowlark
Yellow-headed Blackbird
Brewer's Blackbird
Great-tailed Grackle
Brown-headed Cowbird
House Finch
Lesser Goldfinch
House Sparrow
Species lists were compiled with help from the following sources: