Upland Sonoran Desertscrub
Upland Sonoran desertscrub occupies a relatively large portion of central and southern Arizona with a highly diverse composition and topography. Characteristic vegetation of the upland Sonoran desertscrub includes giant saguaro, cholla, prickly pear, and organ pipe cacti. Common tree and shrub species include palo verde, ironwood, catclaw acacia, mesquite, jojoba, and creosote bush (Dimmitt 2015).
This habitat type tends to receive more precipitation than other desertscrub habitat types (Bradley and Colodner 2019). Annual precipitation primarily comes in two distinct seasons, mid- to late-summer (monsoon) and winter, contributing to the habitat’s rich biodiversity despite being a desert environment (Nabhan 2015). Annual plant species emerge in response to this seasonal precipitation pattern creating brief but remarkable changes to the landscape. If winter rains are hearty, fields of bright green grasses and forbs and beautiful arrays of wildflowers blanket the rocky slopes and valley floors during the spring season.
Arizona contains more Upland Sonoran desertscrub habitat than any other state in North America, putting Arizona in a position of great responsibility for conservation and protection of this unique habitat. Unfortunately, upland Sonoran desertscrub is highly susceptible to development with significant habitat losses occurring in recent decades due to urban expansion into desert environments. These desertscrub habitats are increasingly vanishing and becoming more fragmented, especially surrounding the growing urban areas around Phoenix and Tucson. However, approximately 44% of this habitat type is found in protected areas, mostly managed by federal agencies, such as NPS, USFS, and BLM (Hall et al. 2005). Several species are found in this habitat type that occur nowhere else in the state, including the Sonoran shovel-nosed snake, ferruginous (cactus) pygmy-owl, and three-lined boa (Turner 1994a).
The following describes habitat features or microhabitats that are unique to this habitat type and are of particular importance to certain species:
Springs often support endemic species, such as Bylas springsnail, Montezuma Well springsnail, Gila tryonia, Quitobaquito tryonia, and Sonoyta mud turtle.
Bedrock tinajas in the mountains collect water during rare periods of rain and are critically important sources of water for desert bighorn sheep and other montane species.
Bajadas are the coalescence of alluvial fans along a mountain front where fine sediment is deposited at the end of dry washes and other drainages. Because of this soil composition, bajadas can host a greater diversity of vegetation and more complex vertical structure compared to surrounding areas.
Ephemeral washes and pools are critically important breeding habitats for a variety of desert anurans, including Sonoran green toad, Sonoran desert toad, Sinaloan narrow-mouthed toad, and Arizona toad (Brennen and Holycross 2009). Washes, despite their ephemeral nature, support higher densities of mesquite and ironwood than the surrounding plains. These linear woodlands (or xeric riparian corridors) serve as nesting and stopover sites for birds, provide browse and cover for ungulates, and act as movement corridors for a variety of wildlife species.
Caves and mines are important roost sites for many species of bats. More than half (14) of the bat species that occur in the upland Sonoran desertscrub habitat use caves and mines at some point during the year. Many of the mines lack bat-friendly protections, leaving these species vulnerable to disturbances.
Saguaros, organ pipe cacti and multiple species of Agave provide nectar, pollen, and fruit for two species of nectarivorous bats, as well as a host of other pollinator species, that occur across much of southern Arizona. Invasive buffelgrass and habitat loss is putting increased pressure on these iconic keystone species.
Riparian areas, such as the Middle Gila and Lower Salt rivers are important for wildlife and support the only cottonwood and willow forests in upland Sonoran desertscrub. This riparian forest provides critically important habitat for a variety of species, including southwestern willow flycatcher, western yellow-billed cuckoo, and northern Mexican gartersnake. Additionally, these river systems provide some of the only perennial water found in these hyper-arid areas.
The following list represents SGCN in this habitat type that AZGFD actively manages or are watching closely due to some level of concern:
Bald Eagle, Black-throated Sparrow, Cactus Wren, Canyon Towhee, Costa's Hummingbird, Elf Owl, Cactus Ferruginous Pygmy-Owl, Gila Woodpecker, Gilded Flicker, Golden Eagle, Western Purple Martin, Rufous-winged Sparrow, Southwestern Willow Flycatcher, Western Yellow-billed Cuckoo
Antelope Jackrabbit, Bailey's Pocket Mouse, California Leaf-nosed Bat, Desert Pocket Mouse, Harris's Antelope Squirrel, Lesser Long-nosed Bat, Merriam's Deermouse, Mexican Free-tailed Bat, Mexican Long-tongued Bat, Pale Townsend's Big-eared Bat, Pocketed Free-tailed Bat, Sonoran Pronghorn, Underwood's Mastiff Bat
Arizona Night Lizard, Bezy’s Night Lizard, Black-necked Gartersnake, Gila Monster, Mexican Gartersnake, Regal Horned Lizard, Rosy Boa, Saddled Leaf-nosed Snake, Sonora Mud Turtle, Sonoran Coralsnake, Sonoran Desert Tortoise, Sonoran Shovel-nosed Snake, Sonoyta Mud Turtle, Three-lined Boa, Tiger Rattlesnake, Variable Sandsnake
The following list represents plant species that are known to occur in this habitat type:Tonto Basin agave, Hohokam agave, Trelease agave, Page Springs agave, saiya, aquarius milkvetch, Pima pineapple cactus, Nichol Turk's Head cactus, Acuna cactus, Fish Creek fleabane, Arizona eryngo, Huachuca water-umbel, horseshoe deer vetch, seashore cactus, Chihuahua scurfpea, Verde breadroot, Ajo rock daisy, lace-leaf rockdaisy, Roosevelt Dam rockdaisy, whisk fern, parish alkali grass, Arizona cliff rose, Verde four-nerve daisy
The following are other wildlife species, native and non-native, that can have particular influence in this habitat type. Influential species can affect SGCN and their habitats directly and indirectly, for example altering predator/prey interactions, overgrazing, outcompeting natives, creating microhabitats, and others.
American Bullfrog, Couch's Spadefoot, Red-spotted Toad
Brown-crested Flycatcher, Common Poorwill, Curve-billed Thrasher, Greater Roadrunner, Lucy's Warbler, Song Sparrow
Black-tailed Jackrabbit, Bobcat, California Myotis, Canyon Bat, Cave Myotis, Coyote, Desert Bighorn Sheep, Desert Cottontail, Collared Peccary or Javelina, Mule Deer, Pallid Bat, Ringtail, Western Yellow Bat, White-nosed Coati
Acuna Cactus, Agave spp., Nichol Turk's Head Cactus, Saguaro
Common Chuckwalla, Speckled Rattlesnake
The following describes the primary threats facing this habitat type, adapted from Salafsky et al. (2008). First-level threats (i.e. Agriculture, Climate Change) represent broad categories while second-level threats reflect more specific stressors to the system. For detailed information on threats to this habitat type and conservation actions being taken, see Chapter 8: Threats and Conservation Actions.
2. Biological Resource Use
3. Climate Change and Severe Weather
4. Residential and Commercial Development
5. Disease, Pathogens, and Parasites
6. Energy Production and Mining
7. Human Intrusions and Disturbance
8. Invasive and Other Problematic Species
9. Natural System Modifications
11. Transportation and Service Corridors
The following describes specific conservation actions that can be taken to reduce or eliminate threats to this habitat type, adapted from Salafsky et al. (2008). Level 1 conservation actions (i.e. Land and Water Protection) represent broad categories of potential actions, while the Level 2 conservation actions (i.e. Resource and habitat protection) are more specific.
1. Land and Water Protection
- Identify wildlife corridors essential to the movement of species between high-quality habitat blocks. (Threats 4.1, 4.2)
- Engage communities to incorporate natural resource values and open spaces into long-term planning. Acquire land and water rights, pursue conservation agreements and easements, especially in critical wildlife corridors. (Threats 4.1, 4.3, 6.2, 6.3, 7.1)
- Continue maintenance of wildlife waters to mitigate drought and the effects of temperature extremes. (Threats 3.2, 3.3)
2. Land and Water Management
- Implement projects focused on improving the quality of altered systems creating suitable habitat and/or habitat features for wildlife. Actively seek opportunities to partner with Arizona agricultural producers, private landowners, and land management agencies on a variety of habitat enhancements that benefit both livestock and wildlife. (Threats 1.1, 1.3, 4.1, 4.2, 4.3, 6.2, 6.3, 7.1, 7.3, 9.1)
- Continue disease monitoring efforts for impacted species. Avoid inadvertent spread of disease by following the proper disinfectant protocols. (Threat 5)
- Conduct monitoring and targeted removal efforts to limit establishment and spread of invasive species, especially in COAs or other important wildlife areas. Continue removal activities for trespass livestock, burros, and feral horses on managed lands. (Threats 1.1, 1.3, 8.1, 9.1)
4. Education and Awareness
- Engage communities to incorporate natural resource values and open spaces into long-term planning. (Threats 1.1, 1.3, 4.1, 4.2, 4.3, 6.3, 7.1, 7.3, 10.1, 10.2, 10.3, 10.4, 11.1)
- Conduct emerging disease education and outreach to user groups who potentially come into contact with affected species. Provide education on methods for avoiding the spread of diseases, pathogens, and parasites into novel populations of wildlife (i.e. bats and white-nose syndrome). (Threat 5)
- Provide extensive educational outreach through public events, social media messaging, billboards, and partnering with AZ State Parks, OHV dealers, OHV rental companies as well as off-road clubs and organizations. Educate new outdoor enthusiasts on safe, ethical practices and proper behavior in natural settings and in proximity to wildlife. (Threats 4.3, 7.1, 11.1)
- Expand wildlife viewing programs to improve associated infrastructure (signs, platforms, etc.) and to reach larger and more diverse audiences. (Threats 4.3, 7.1)
- Work with developers, federal permitting agencies, the Arizona Corporation Commission, and state and local governments to raise awareness of impacts to wildlife and habitat from renewable and nonrenewable energy development. (Threats 6.3, 11.2)
- Develop outreach programs for the public on impacts to wildlife, agriculture, and recreation from introduced species. Incorporate citizen science programs to identify distribution of invasives (such as iMapInvasives.org). (Threat 8.1)
5. Law and Policy
- Conduct statewide law enforcement patrols targeting illegal OHV use as well as targeted saturation patrols in areas identified as critical habitat that are being adversely impacted by OHV and recreational activities. (Threat 7.1)
- Inform federal and state agencies of critical need for wildlife movement across the international border with Mexico, and help design any necessary border barriers to allow wildlife movement. (Threat 7.3)
- Conduct statewide law enforcement patrols targeting illegal take of wildlife, especially during scheduled hunts. (Threat 2.1)
6. Livelihood, Economic and Other Incentives
- Collaborate with the development and renewable energy industries to incorporate BMPs and other measures to reduce impacts to wildlife and habitats. Identify ways for incentivizing incorporation of recommendations. (Threats 4.1, 4.2, 6.3)
- Work with local governments to incorporate wildlife protections and habitat connectivity into general plans. (Threats 4.1, 4.2, 6.3)
- Share information and discuss the benefits of participating in species recovery programs such as Safe Harbor Agreements, Habitat Conservation Plans, Candidate Conservation Agreements with Assurances, and Candidate Conservation Agreements with interested landowners. (Threats 1.3, 4.1)
7. External Capacity Building
- Collaborate with partners across different geographies (e.g., statewide, regional, national and international) to develop and implement management plans, conservation agreements, recovery actions, research, management recommendations, and to determine the effectiveness of specific management efforts for long-term conservation of SCGN wildlife. (Threats 3.1, 3.2, 3.3, 3.4, 5, 8.1)
The following describes some of the conservation strategies that may mitigate the effects of a changing climate for this habitat type. Strategies have been adapted from guidelines by the Association of Fish and Wildlife Agencies (AFWA 2009).
Identify and improve the connectivity of natural landscapes to better link wildlife populations and allow for range shifts.
Identify populations that could benefit from assisted migrations/translocation.
Implement long-term monitoring protocols for vulnerable species and habitats to inform adaptive management.
Establish new wild and/or captive populations of climate vulnerable SGCN.
Maintain existing and identify new wildlife waters for drought mitigation.
Monitor for new populations of introduced and invasive species.
Establish refugia for at-risk species (e.g. springsnail species, desert pupfish).
The following describe other routine or on-going conservation actions AZGFD regularly performs in this habitat type:
- Conduct surveys and monitor populations of SGCN as specified in work plans and job statements.
- Implement conservation actions to promote populations of SGCN species, including translocations and insurance populations when necessary.
- Collect specimens or samples for taxonomic analysis, genetics, research, and/or disease testing.
- Fund or work with partners to conduct conservation-related species research.
The following represents identified COAs where conservation efforts would benefit wildlife and their habitats.
- Agua Fria Riparian Corridor
- Bill Williams Complex
- Buenos Aires NWR and Altar Valley
- Bush Fire and Three Bar Natural Research Area
- Central Yavapai County
- Desert Mountains Complex
- Estrella Maricopa Corridor
- Gila Box
- Goodwin and Contreras Mesas
- Harquahala Plain
- Ironwood National Monument
- Joshua Tree
- King Valley
- Kofa Mountains
- Lake Havasu
- Lower San Pedro River
- McDowell-Superstitions-Mazatzal Mountains Linkage
- Palomas Plain
- Phoenix Area Snails
- Porter Springs Wash and Cold Springs
- Queen Creek
- Roosevelt Lake Wildlife Area
- Salt-Verde Ecosystem
- San Pedro Riparian National Conservation Area
- Sonoran Desert Borderlands
- Table Top Mountains
- Telegraph and Mescal Fires
- Tonto Creek
- Tortolita Mountains
- Tucson Mountains
- Tucson Sky Islands
- Vekol Valley
- Weaver Mountains
The following is a list of the organizations and agencies that AZGFD regularly partners with on conservation efforts in this habitat type:
- Arizona Center for Nature Conservation-Phoenix Zoo
- Bat Conservation International
- Desert Botanical Garden
- Central Arizona Conservation Alliance
- Arizona-Sonora Desert Museum
- Tohono O'odham Nation
- Gila River Indian Community
- Department of Defense - Barry M. Goldwater Range
- Department of Defense Yuma Proving Ground
- Bureau of Land Management
- National Parks Service
- USFWS Arizona Ecological Services
- US Bureau of Reclamation
- Tucson Audubon Society
- Audubon Southwest
- Arizona Field Ornithologists
- Sonoran Joint Venture
- Sky Island Alliance
- Sonoran Desert Comprehensive Weed Management Area
- Pima County
- Pinal County
- Maricopa County
- La Paz County
- US Army Corps of Engineers
- Arizona Monarch Collaborative
- Southwest Monarch Study
- Gila Watershed Partnership
The following are relevant conservation agreements, plans, and other documents or particular interest regarding wildlife in this habitat type:
- Candidate Conservation Agreement for Sonoran Desert Tortoise
- CCAA - AZ Electric Power Co-op CCAA for the Sonoran Desert Tortoise
- Quitobaquito Tryonia Strategic Conservation Plan (In review)
- BLM Statewide Springsnail Strategic Conservation Plan (CCA format; 2022 Planned)
- Proposed Critical Habitat for Northern Mexican Gartersnake
- BLM Instruction Memorandum (IM) 2010-181, White Nose Syndrome
- Western Burrowing Owl Management Resources
- USFWS White-nose Syndrome National Plan
- MOU Between BLM and USFWS for Conservation of Migratory Birds
- Pima County Multi-Species Conservation Plan
- Draft Post-Delisting Monitoring Plan for the Lesser Long-nosed Bat, 2019
- Arizona Partners in Flight Bird Conservation Plan
- Arizona Bat Conservation Strategic Plan
- Western Monarch Butterfly Conservation Plan