Arizona Wildlife Conservation Strategy

Mohave Desertscrub

Mohave desertscrub occurs in northwestern Arizona, southern Nevada and southeastern California generally at elevations between 1,000 to 3,000 feet above sea level. Landscapes are typically quite barren and desolate in appearance with low, scattered shrubs. Although this landscape is shrub-dominated and lacks giant cacti and many tree species, several large plants such as the Joshua tree and Mohave yucca are common, and mesquites and cat-claw acacia are present (Turner 1994c). Other predominant plant species include creosote bush, brittlebush, desert holly, and white bursage with smaller cacti present along slopes. Hot summers and cool winters are typical with the majority of the annual precipitation (5 to 11 inches) falling in the winter (USGS 2005). There are few SGCN species that inhabit this region that are not found elsewhere in the state or in only one or a few habitat types. Examples of these species include Mojave desert tortoise, relict leopard frog, Kingman springsnail, and Mohave talussnail.

In recent decades, the historical distribution of Mohave desertscrub in Arizona has been reduced through habitat loss and fragmentation due to agricultural operations and low-density development across the landscape (Averill-Murray et al. 2021). With this increase in habitat loss, habitat fragmentation has increased causing wildlife to become displaced and genetic diversity to decrease. A significant portion of Mohave desertscrub distribution is federally-managed. This offers some degree of protection from development on the landscape.

Significant Habitat Features

The following describes habitat features or microhabitats that are unique to this habitat type and are of particular importance to certain species:

  • Riparian areas, such as the Colorado River and Virgin River are extremely important for wildlife in Mohave desertscrub habitats. Riparian areas and associated marshlands provide habitat for a variety of native species, including federally-listed species like Yuma Ridgway’s rail, southwestern willow flycatcher, western yellow-billed cuckoo, and northern Mexican gartersnake.

  • Springs exist on the landscape when water pressure in the aquifer pushes water through cracks or tunnels and flows naturally to the surface. These springs create isolated pockets of habitat and often support endemic species, such as Grand Wash springsnail, Kingman springsnail, desert springsnail, relict leopard frog, and lowland leopard frog.

  • Joshua tree forests in Arizona are restricted to small areas of Mohave desertscrub in the northwest portion of the state. These habitats are an important part of the Mohave Desert ecosystem and are a host to unique species of yucca that provide resources for many pollinators, birds, mammals, and lizard species. 

  • Caves and mines are important roost sites for many species of bats. Many of the bat species that occur in the Mohave 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.

  • Playas occur in intermountain basins throughout the arid southwestern United States. Although playas may appear as featureless plains, they are rich in features and characteristics that can reveal information about climates, past and present (USGS 2009).

Strategy Species

The following list represents SGCN in this habitat type that AZGFD actively manages or are watching closely due to some level of concern:

Amphibians

Arizona Toad, Lowland Leopard Frog, Relict Leopard Frog

Birds

American Peregrine Falcon, Bald Eagle, Bendire's Thrasher, Black-throated Sparrow, Cactus Wren, California Condor, Ferruginous Hawk, Golden Eagle, LeConte's Thrasher, Loggerhead Shrike, Swainson's Hawk, Western Burrowing Owl

Invertebrates

Desert Springsnail, Grand Wash Springsnail, Kingman Springsnail, Apache Talussnail

Mammals

Allen's Lappet-browed Bat, American Pronghorn, California Leaf-nosed Bat, Mexican Free-tailed Bat, Pale Townsend's Big-eared Bat

Reptiles

Gila Monster, Mojave Desert Tortoise, Sonoran Desert Tortoise

Sensitive Plant Species

The following list represents plant species that are known to occur in this habitat type:

Arizona pricklypoppy, Holmgren (Paradox) milk-vetch, freckled milk-vetch, Kaibab suncup, Tabeau Peak wild buckwheat, Black Mountains monardella, Siler pincushion cactus, Higgins' phacelia, Arizona rose sage, Gierisch mallow

Additional Influential Species

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.

Amphibians

Red-spotted Toad, Woodhouse's Toad

Birds

Ash-throated Flycatcher, Black-tailed Gnatcatcher, Greater Roadrunner

Mammals

Black-tailed Jackrabbit, Bobcat, Coyote, Desert Bighorn Sheep, Desert Cottontail, Collared Peccary or Javelina, Mule Deer, Pallid Bat, Yuma Myotis

Plants

Creosote, Joshua Tree, Mojave Yucca

Reptiles

Common Chuckwalla

Threats

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.

1. Agriculture

1.3: Livestock farming and ranching
Historical and current overgrazing on the landscape has affected the native plant populations. With overgrazing and drought prevalent, non-native plant species, such as cheatgrass, have taken over areas once dominated by native vegetation. Agriculture operations in a drought driven environment have contributed to a decreased water table.

2. Biological Resource Use

2.1: Unlawful take of terrestrial animals
2.2: Unlawful take of terrestrial plants
Unlawful take of terrestrial animals or plants can be detrimental to populations that have slow recruitment. Excess harvest can substantially impact populations of species with small populations and reduce their ability to recover from stochastic events, such as drought or wildfire.

3. Climate Change and Severe Weather

3.1: Habitat shifting and alteration
3.2: Droughts
With climate change, warmer ambient temperatures may surpass species’ temperature tolerances, causing local extinctions or changing the distribution of less heat-tolerant species. Climate change also results in altered precipitation patterns, affecting hydrological regimes (more droughts and floods) which can adversely influence terrestrial plant and wildlife distributions.

4. Residential and Commercial Development

4.1: Housing and urban areas
4.2: Commercial and industrial areas
4.3: Tourism and recreation areas
With the human population increasing in Arizona, the expansion of development on the landscape is having direct and indirect effects on wildlife. Direct effects are on habitat loss, degradation, and fragmentation, while indirect effects are pollution from light and noise.

5. Disease, Pathogens, and Parasites

5: Disease, Pathogens, and Parasites
Species in the desertscrub habitat can be affected by a variety of diseases, including rabies, hantavirus, West Nile virus, rabbit hemorrhagic disease, and white-nose syndrome. These diseases can have detrimental impacts on wildlife populations, causing significant mortalities and drastic population declines as well as decreased reproduction and recruitment of young. When a species encounters a new disease, it can take years for the recovery of the population to take place.

6. Energy Production and Mining

6.2: Mining and quarrying
6.3: Renewable energy
Mohave desertscrub is home to several old, new, and proposed mining claims and to several solar farms and wind farms. These mining operations can cause habitat loss/fragmentation, draw down of water and general disturbance. Renewable energies can cause direct mortality from collisions with wind turbines or impacts with solar mirrors.

7. Human Intrusions and Disturbance

7.1: Recreational activities
7.3: Work and other activities
Poorly-managed recreational activities, such as illegal OHV use, can degrade desertscrub by damaging habitats, increasing erosion, harming delicate vegetation, and altering wildlife behavior. These types of alterations can negatively-affect desertscrub species abundance and distributions due to the lack of quick regeneration of native plant species.

8. Invasive and Other Problematic Species

8.1: Invasive non-native species
8.2: Problematic native species
Invasive and problematic species — such as feral burros, unrestrained pets, non-native mussels, non-native grasses — compete with native fauna, over-utilize native species, affect native species’ gene pool through hybridization, and cause habitat damage. This can alter the structure of these habitats and communities making them less desirable or unusable to native species.

9. Natural System Modifications

9.1: Fire and fire suppression
9.2: Dams and water management
9.3: Other ecosystem modifications
Increase in wildfires fueled by invasive annual grasses has resulted in the overgrowth of non-native plant species that offer little to no nutritional value for wildlife. Dams and water management activities change lotic systems to lentic systems, and alter or completely dry downstream lotic systems. Other ecosystem modifications for the Mohave desertscrub include the destruction of riparian areas, overgrazing, and dusting wallows.

10. Pollution

10.1: Household sewage and urban waste water
10.4: Garbage and solid waste
Pollution can lead to habitat degradation, behavior modification from noise, direct mortality/reduced fecundity, and loss of food and water. Sources of pollution include leaking septic and fuel tanks, untreated sewage, oil or sediment on roads, lawn and agricultural fertilizers and herbicides, illegal dump sites, mine tailings, road-side litter, construction-site debris, and solid garbage and waste.

11. Transportation and Service Corridors

11.1: Roads and railroads
11.2: Utility and service lines
The creation of new roads and current travel corridors can be both a direct and indirect threat to species in the area. Vehicle traffic can create noise and visual disturbance, altering behavior of wildlife species. Road construction and maintenance may result in the direct loss of habitat and disrupt migration corridors. The construction of new roads is also in coordination with new utility and service lines on the landscape.

Conservation Actions

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

1.1: Site/area protection
  • Identify wildlife corridors and seek land acquisition essential to the movement of species between high-quality habitat blocks. (Threat 4.1)

2. Land and Water Management

2.3: Habitat and natural process restoration
2.2: Invasive/problematic species control
  • Improve rangeland health by creating suitable habitat and/or habitat features for wildlife; partner with agricultural producers and private landowners on a variety of habitat enhancements that benefit both livestock and wildlife. (Threats 1.1, 10.1)
  • To reduce adverse effects to habitat, control the spread of and remove non-native, undesirable, and/or invasive wildlife and plant species, including unauthorized livestock, burros, and feral horses; remove these species where they are not managed at appropriate levels. (Threat 8.1)

4. Education and Awareness

4.3: Awareness and communication
  • Engage communities to incorporate natural resource values and open spaces into long-term planning; increase public awareness of AZGFD’s nongame conservation efforts to gain the support of non-traditional constituencies. (Threat 4.1)
  • 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 non-renewable energy development. (Threats 6.2, 6.3)
  • Expand wildlife viewing programs to improve associated infrastructure (signs, platforms, etc.) and to reach larger and more diverse audiences. (Threats 4.3, 7.1)
  • Increase educational outreach through public events, social media messaging, and partnering with AZ State Parks, OHV dealers, and off-road clubs and organizations; improve coordination with partners to discuss priorities and how the AWCS can be used to facilitate project planning and implementation. (Threat 7.1)
  • Improve coordination with partners to identify priorities and how the AWCS can be used to facilitate project planning and implementation; mitigate transportation impacts by constructing wildlife crossing structures, avoiding wildlife corridors, and signage, etc., when major roadway/highway construction will be occurring. (Threat 11.1)

5. Law and Policy

5.2: Policies and regulations
5.4: Compliance and enforcement
  • Improve coordination with partners to identify priorities and how the AWCS can be used to facilitate project planning and implementation; mitigate transportation impacts by constructing wildlife crossing structures, avoiding wildlife corridors, and signage, etc., when major roadway/highway construction will be occurring. (Threat 7.1)

7. External Capacity Building

7.2: Alliance and partnership development
  • Collaborate with partners at different scales (e.g., statewide, regional, national, and international) to develop and implement management plans, conservation agreements, recovery actions, research, management recommendations, and determine specific management efforts to improve and coordinate landscape-scale efforts for long-term conservation of SCGN wildlife. (Threats 3.1, 3.2, 3.3)

Conservation in the Context of Climate Change

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).

  • Conserve a variety of habitats that support healthy populations of fish and wildlife as climate changes.

  • Establish new wild and/or captive populations of climate vulnerable SGCN.

  • Identify and improve the connectivity of natural landscapes to better link wildlife populations and allow for range shifts.

  • Collect specimens or samples for taxonomic analysis, genetics, research, and/or disease testing.

  • Conduct research targeting species and habitat types likely to be vulnerable to climate change impacts.

  • Implement long-term monitoring protocols for vulnerable species and habitats to inform adaptive management.

Other Conservation Actions

The following describe other routine or on-going conservation actions AZGFD regularly performs in this habitat type:

  • Monitor white-nose syndrome on BLM-administered lands with various funding sources. Mines/caves are gated or closed dependent on the bat resources found.
  • Monitor for epizootic pneumonia disease in the Black Mountain desert bighorn sheep population.
  • Conduct surveys and monitor populations of SGCN as specified in work plans and job statements. Survey other influential species within the habitat to minimize negative impacts to habitat and associated species.
  • Fund or work with partners to conduct conservation-related species research.
  • Manage recreational activities and OHV use of desertscrub habitat to minimize negative impacts to habitat and associated species.
  • Collect samples for taxonomic analysis, genetics, research, and/or disease testing.

Conservation Opportunity Areas (COAs)

The following represents identified COAs where conservation efforts would benefit wildlife and their habitats.

Potential Partnerships

The following is a list of the organizations and agencies that AZGFD regularly partners with on conservation efforts in this habitat type:

Important Conservation Resources

The following are relevant conservation agreements, plans, and other documents or particular interest regarding wildlife in this habitat type: