Caja Del Rio - Ecology

Ecology

Soils in the Caja del Rio are derived from Tertiary volcanic basalt flows and cinder cone eruptions. Most are best characterized as stony or cindery loam, with shallow horizons. Soil surveys of the Caja generally describe the soils as unsatisfactory, with a reduced potential for hydrologic and nutrient function.

Three primary plant communities are frequently found on the Caja del Rio plateau: Pinon-Juniper Savanna, Pinon-Juniper Woodland, and Great Basin Sage Scrub. The most prevalent vegetative communities consist of a pinon (Pinus edulis) and juniper (Juniperus monosperma) overstory with a short grass understory. Tree densities often range between 100 and 300 trees per acre. Another large community consists of open grassland, with blue grama (Bouteloua gracilis), galleta (Pleuraphis jamesii), and various species of Stipa being the most common grasses. Common woody shrubs include Chamisa (Chrysothamnus nauseosus), Apache plume (Fallugia paradoxa), Four-wing saltbush (Atriplex canescens), and Big sagebrush (Artemisia tridentata).

Predatory mammals known to live in the Caja del Rio include black bear (Ursus americanus), mountain lion (Felis concolor), bobcat (Lynx rufus), coyote (Canis latrans), fox (Vulpes spp), gray fox (Urocyon cinereoargenteus), ringtail (Bassariscus astutus), badger (Taxidea taxus), long-tailed weasel (Mustela frenata), Western Spotted Skunk (Spilogale gracilis), and Striped Skunk (Mephitis mephitis). Non-predatory mammals known to be present include Rocky Mountain elk (Cervus elaphus), mule deer (Odocoileus hemionus), raccoon (Procyon lotor), porcupine (Erethizon dorsatum), Black-tailed jackrabbit (Lepus californicus), desert cottontail, (Sylvilagus auduboni), White-throated Woodrat (Neotoma albigula), Botta's pocket gopher (Thomomys bottae), Colorado chipmunk (Neotamias quadrivittatus), Pinyon Mouse (Peromyscus truei), and Deer mouse (Peromyscus spp.). Sensitive mammalian species known to be present at the Caja include Gunnison's prairie dog (Cynomys gunnisoni). A small herd of wild horses (consisting of approximately 50 individuals) lives year round on the plateau.

Birds of prey found in or near the Caja include Bald eagle (Haliaeetus leucocephalus), golden eagle (Aquila chrysaetos), Red-tailed hawk (Buteo jamaicensis), Ferruginous hawk (Buteo regalis), Swainson's hawk (Buteo swainsonii), American Kestrel (Falco sparverius), and Peregrine falcon (Falco peregrinus anatum), Other resident non-migratory birds include Merriam's turkey (Meleagris gallopavo), Pinyon Jay (Gymnorhinus cyanocephalus), Hairy Woodpecker (Picoides villosus), and Scaled Quail (Callipepla squamata).

Migratory birds found in or near the Caja include Turkey vulture (Cathartes aura), Killdeer (Charadrius vociferus), Loggerhead Shrike (Lanius ludovicianus), Common nighthawk (Chordeiles minor), mourning dove (Zenaida macroura, Broad-tailed Hummingbird (Selasphorus platycercus), Ladder-backed Woodpecker (Picoides scalaris), Downy woodpecker (Picoides pubescens), Northern flicker (Colaptes auratus), American Gray Flycatcher (Empidonax wrightii), Say's Phoebe (Sayornis saya), Ash-throated Flycatcher (Myiarchus cinerascens), Cassin's Kingbird (Tyrannus vociferans), Plumbeous Vireo (Vireo plumbeus), Horned lark (Eremophila alpestris), Violet-green swallow (Tachycineta thalassina), Northern Rough-winged swallow (Stelgidopteryx serripennis), Blue-gray Gnatcatcher (Polioptila caerulea), Western bluebird (Sialia mexicana), Mountain bluebird (Sialia currucoides), Townsend's Solitaire (Myadestes townsendi), American Robin (Turdus migratorius), American pipit (Anthus rubescens), Black-throated Gray Warbler (Dendroica nigrescens), Western Tanager (Piranga ludoviciana), Chipping Sparrow (Spizella passerina), Lark Sparrow (Chondestes grammacus), Western Meadowlark (Sturnella neglecta), and Brown-headed Cowbird (Molothrus ater). Waterfowl using the Rio Grande corridor include Canada goose (Branta canadensis), mallards (Anas platyrhynchos), northern pintails (Anas acuta), and American wigeon (Anas americana).

Sensitive bird species known to be present at the Caja include bald eagles, peregrine falcons, and Gray Vireos.

Common reptiles include Collared lizards (Crotaphytus collaris), Roundtail Horned Lizard (Phrynosoma modestum), Striped whipsnake (Masticophis taeniatus), and Western diamondback rattlesnake (Crotalus atrox). Sensitive reptilian species include the Desert kingsnake (Lampropeltis getula splendida).