The state of Arizona is famous for its deserts, with hot summers and mild winters, especially in the southern region. Elsewhere, such as in the higher altitudes of the north-central part of the state, temperate coniferous forests offer cooler temperatures with more precipitation, including snow. These diverse climate conditions support over 100 species of reptiles, with an especially high diversity of snakes and lizards that thrive in the desert.
While many herpers are drawn to Arizona in hopes of spotting iconic venomous species like the Gila monster (Heloderma suspectum) or sidewinder (Crotalus cerastes), the Grand Canyon state is also home to six species of native turtles. Of the state’s native turtles, two are desert tortoises with unique adaptations for surviving in extremely dry climates. For clarification purposes, technically all tortoises are turtles — that is, members of the order Testudines — but not all turtles are tortoises. The painted turtle, which is native to the Lyman Lake area of Northeastern Arizona but introduced in other parts of the state, is occasionally included in lists of native turtle species.
Several non-native turtle species can be found in the state, likely released from the pet industry intentionally or by accident. Some turtle species can be caught with an appropriate hunting or fishing license, with invasive turtle species such as red-eared sliders, spiny softshells, and snapping turtles having no bag or possession limit in designated areas.
The breeding and release of captive turtles pose serious threats to Arizona turtles, and specifically, it is illegal to breed captive desert tortoises. Similarly, small turtles under 4 inches in length cannot be sold as pets; a ban that was enacted to promote responsible turtle ownership.
Native Turtle Species
1) Arizona mud turtle (Kinosternon stejnegeri)
- Family: Kinosternidae
- Other names: None
- Average adult length: 3.1 – 6.5 in (7.9 – 16.5 cm)
- Conservation status: IUCN least concern, ESA not listed, Arizona state not listed
The Arizona mud turtle is a dark, medium size turtle that varies in color from olive-brown to yellowish-brown. The carapace, or upper shell, is dome-shaped without a keel (a ridge that runs from the front to the back of the animal). The rim of the shell and the plastron (the lower shell) are yellow. This turtle has a gray head with a yellow- or cream-colored underside. Males tend to be somewhat smaller than females.
Arizona mud turtles are found in south-central Arizona and north-central Mexico. They are mostly diurnal but can be more nocturnal during the rainy season. Their main prey includes tadpoles, frogs, invertebrates, and occasionally carrion. Arizona mud turtles typically lay eggs between July and August, usually burying the eggs near a favored pond or puddle that provides a consistent food source.
Formerly, the Arizona mud turtle was considered a subspecies of the yellow mud turtle called the Arizona yellow mud turtle (K. f. arizonense), and some debate exists over its validity as a separate species. Due to its former classification, the Arizona mud turtle is sometimes mistakenly referred to as K. arizonense, although this scientific name specifically refers to an extinct but closely related species known only from the fossil record.
2) Yellow mud turtle (Kinosternon flavescens)
- Family: Kinosternidae
- Other names: Yellow-necked mud turtle
- Average adult length: 3.3 – 6.6 in (8.4 – 16.8 cm)
- Conservation status: IUCN least concern, ESA not listed, Arizona state not listed
Found throughout the central United States and Mexico, the yellow mud turtle is a small turtle with a flat or slightly concave carapace that ranges in color from olive to yellowish-brown. The “yellow” from its name refers to yellow patches on the throat, head, and neck. The plastron is hinged on both ends, allowing the turtle to fully close itself inside its shell. Male turtles have a blunt, hooked spine on the tip of the tail, while females do not. Unlike the similar-looking Sonora mud turtle, the head is never mottled.
These turtles are highly omnivorous, consuming a variety of invertebrates as well as fish, frogs, tadpoles, and occasional vegetation, as they are capable of foraging for food in the water as well as on land. Uniquely, they are the only turtle known to provide parental care for their eggs and will stay with their nest for as long as 38 days. Though adult yellow mud turtles have few predators, eggs and juveniles are susceptible to predation by mammals, snakes, and birds. Yellow mud turtles can live up to 40 years, though most have an average lifespan of around 15 years.
Though considered endangered at the state level in places such as Missouri, yellow mud turtles are not protected at the federal level or at the state level in Arizona. In Arizona, yellow mud turtles are found only in the extreme southeast corner of the state, with habitat preferences including grasslands and open woodlands with shallow pools or stock tanks with muddy or sandy bottoms.
3) Sonora mud turtle (Kinosternon sonoriense)
- Family: Kinosternidae
- Other names: Sonoyta mud turtle
- Average adult length: 3.1 – 6.5 in (7.9 – 16.5 cm)
- Conservation status: IUCN near threatened, ESA endangered (subspecies K. s. longifemorale only), Arizona state protected
The Sonora mud turtle can be found in Arizona and New Mexico, as well as the states of Chihuahua and Sonora in Mexico. They have a keeled olive or brown carapace and a brown throat and neck with yellow stripes or spots, which can help differentiate them from other mud turtles in the western region. Under the chin, prominent tubercles are present, sometimes described as “nipple-like” projections.
Sonoran mud turtles are primarily found in springs, creeks, and ponds in woodlands of oaks, conifers, or mixed piñon-juniper, as well as foothill grasslands and deserts. They are less common than yellow mud turtles in lowlands and usually stay near water (including occasional stock ponds). Though capable of moving on land, Sonora mud turtles are much more aquatic than other mud turtle species, and their survival is heavily influenced by the amount of rainfall.
Two subspecies are recognized, the Sonora mud turtle (K. s. sonoriense) and the Sonoyta mud turtle (K. s. longifemorale), though sometimes the names are used interchangeably at the species level. While the Sonora mud turtle is wide-ranging throughout the state of Arizona, the Sonoyta subspecies is listed as federally endangered.
Sonoyta mud turtles are found in the Rio Sonoyta and Rio Guadalupe basins — extremely arid environments where agriculture, groundwater pumping, and drought threaten the five remaining populations of this subspecies (only one of which is in the United States). This subspecies is particularly vulnerable to extinction because they often reside in isolated pools or ponds that are susceptible to drying out completely, leaving the turtles without the habitat and water resources they require.
While habitat protections were put in place to protect this vulnerable population of only about 150 total turtles, the construction of the US-Mexico border wall also threatens the persistence of their key habitats by removing aquifer water and disrupting the springs and ponds the turtles rely on for survival.
4) Morafka’s desert tortoise (Gopherus morafkai)
- Family: Testudinidae
- Other names: Sonoran desert tortoise
- Average adult length: 8 – 15 in (20.3 – 38.1 cm)
- Conservation status: IUCN no status, ESA not listed, Arizona state protected
Once considered the same species as Agassiz’s desert tortoise, molecular evidence from a 2011 study indicated that Morafka’s desert tortoise — named for a professor at California State University, Dominguez Hills — was actually a distinct species. They are very similar in appearance to Agassiz’s desert tortoise and are most easily distinguished by DNA evidence. However, the gular shields (the most anterior part of the plastron, or in other words, the scutes on the underside of the shell closest to the head) of Morafka’s desert tortoise are shorter and the width of the carapace is narrower. They are also more likely to be found hiding or burrowing under crevasses on steep, rocky hillsides.
Geographically, they are found east of the Colorado River with their range including south-central and western Arizona, then extending into Sonora and Sinaloa in Mexico. Like other desert tortoises, they are herbivores that consume cacti, grasses, herbs, wildflowers, and fruits. Ingestion of rocks or soil also aids in digestion and provides key minerals like calcium. These plants are their primary source of water, though desert tortoises will drink from water pools following rain. To escape extreme desert temperatures, which can exceed 120°F during the day or near freezing at night, these tortoises dig burrows 3 – 6 feet deep.
Though threatened by development, drought, human harassment, and the introduction of non-native vegetation, a recent ruling determined that Morafka’s desert tortoise inhabits much of its historical range and therefore does not require federal protection by the Endangered Species Act. Due to concerns over increasing drought risk and climate change, the decision remains controversial.
This species is still protected by Arizona state law, and it is illegal to harm or capture wild Morafka’s desert tortoises. Similarly, the release of captive individuals is also prohibited to limit potential damage from disease introduction or behavioral disruption. Desert tortoise adoption programs have been established in Arizona as an incentive to limit the release of these long-lived animals — which can reach 80 years in age.
5) Agassiz’s desert tortoise (Gopherus agassizii)
- Family: Testudinidae
- Other names: Mojave desert tortoise
- Average adult length: 8 – 15 in (20.3 – 38.1 cm)
- Conservation status: IUCN critically endangered, ESA threatened, Arizona state protected
Similar in appearance to Morafka’s desert tortoise, Agassiz’s desert tortoise has a high domed shell decorated with prominent growth lines on the carapace and plastron. They are gray, brown, or ivory in color with stocky, elephant-like legs and short tails. They are completely terrestrial, adapted for life on land in habitats ranging from creosote bush flats to hillsides or juniper woodlands.
In Arizona, their habitat usually includes palo verde trees and saguaro cactus. Agassiz’s desert tortoises are found west of the Colorado River in southeastern California and near the four corners area, including the Black Mountains in the northwest corner of Arizona. They can inhabit areas below sea level, like Death Valley, and up to 3,500 feet in elevation.
Typically, habitats with sandy or loamy soils are preferred, as this allows these tortoises to dig burrows to escape excessive heat. Burrows can be identified by their half-moon-shaped openings, and each tortoise may use between 5 and 25 burrows per year, which may be shared with other desert animals like small mammals, burrowing owls, or snakes.
Since the 1980s, these gentle giants have declined in population size by as much as 90%, which has largely been attributed to habitat loss and degradation (especially due to cattle grazing and off-road vehicles), illegal collection, and disease. For example, the release of captive tortoises has led to an increase in the spread of the bacteria Mycoplasma agassizii and M. testudineum, which are highly contagious and spread quickly between individuals.
These bacteria cause upper respiratory infections with symptoms such as runny noses or blocked nasal passages, pneumonia, and lethargy which are ultimately fatal for many desert tortoise individuals. As such, Agassiz’s desert tortoise is federally listed as threatened, with the International Union for Conservation of Nature also listing them as critically endangered. Conservation efforts to protect Agassiz’s desert tortoise include range-wide monitoring, translocations, and reduction of predators such as common ravens.
6) Desert box turtle (Terrapene ornata luteola)
- Family: Emydidae
- Other names: Western box turtle, ornate box turtle, yellow box turtle
- Average adult length: 4 – 5.8 in (10.2 – 14.7 cm)
- Conservation status: IUCN near threatened, ESA not listed, Arizona state protected
A subspecies of the ornate box turtle (T. ornata), the desert box turtle is found in semi-desert grasslands, desert scrub, and evergreen woodlands at elevations as high as 7100 feet. Box turtles are named for their hinged shells in which they can completely enclose themselves. Ornate box turtles have a high, rounded shell with radiating marks of dark lines or dots on a yellow or ivory-colored background. The plastron usually has similar markings, though some rare individuals may lack markings.
The desert box turtle has 11 – 14 radiating lines on its shell, which can help distinguish it from the other ornate box turtle subspecies (T. o. ornata), which has only 5 – 10 radiating lines. As desert box turtles age, their lines may become less distinct over time, whereas the ornate box turtle does not experience fading of the shell. The desert box turtle also has more muted colors, as an adaptation for camouflage with its desert surroundings. Males have red eyes and a bluish head, while females have brown or yellow eyes.
This turtle is highly terrestrial and faces a drier and more extreme environment than other North American box turtles. They are omnivores, consuming a variety of vegetation as well as insects and other small animals. Foraging typically occurs during the day in the early morning, with turtles digging burrows to escape excessively hot or dry conditions. Desert box turtles are secretive and difficult to find, so little is known about their population trends. The construction of roads has isolated populations from each other, while vehicle collisions contribute directly to turtle mortality, thus presenting major threats to desert box turtles.
In Arizona, box turtles are protected by the state, and it is illegal to collect them from the wild. Additionally, state efforts to better assess population trends include a citizen science approach, where any observed box turtles can be reported to the state wildlife department.
Non-Native Turtles
1) Painted turtle (Chrysemys picta)
- Family: Emydidae
- Other names: Western painted turtle
- Average adult length: 2.5 – 10 in (6.4 – 25.4 cm)
- Conservation status: IUCN least concern, ESA not listed, Arizona state not listed
Painted turtles are wide-ranging in the United States, found throughout eastern, central, and northwestern parts of North America in most major river basins. They have a low, unkeeled carapace that is usually black, brown, or olive green, with their head and forelimbs decorated by yellow striped markings. Unlike similar-looking red-eared sliders, the painted turtle is flatter and never has a prominent red marking on the side of its head.
Painted turtles are often divided into four subspecies that are correlated with geographic location, with the western painted turtle subspecies (C. p. bellii) found in Arizona and most of the range west of the Mississippi River. Western painted turtles are on average the largest subspecies by body size. These turtles are highly aquatic, preferring slow-moving fresh waters and wetlands.
Painted turtles consume many types of vegetation and animal prey, with considerable variation in their diet depending on seasonality and geographic location. Due to their reliance on water and aquatic habitats, their prevalence in Arizona is generally limited and their range throughout the southwest is highly fragmented.
In Arizona, these turtles are native to a single area: Lyman Lake in eastern Arizona, the largest lake in the region at 1,400 acres, with water brought from the Little Colorado River. From this part of their native range, painted turtles likely dispersed into other areas with canals or ponds constructed for human developments in Phoenix, Tucson, and Cottonwood. A favorite of the pet trade, the painted turtle may have also been accidentally or intentionally introduced by humans to other areas in the west outside of its native range.
2) Red-eared slider (Trachemys scripta elegans)
- Family: Emydidae
- Other names: Pond slider
- Average adult length: 5 – 8 in (12.7 – 20.3 cm)
- Conservation status: IUCN least concern, ESA not listed, Arizona state not listed
The most popular pet turtle in North America, the red-eared slider is native to the south-central part of the United States and north-central Mexico, but they are not native to Arizona. Superficially, they resemble painted turtles, but with a rounder and more prominent shell and a distinct broad red stripe on the ear. In some rare cases, the ear stripe may be yellow.
Red-eared sliders are aquatic turtles, yet they can wander far on land and can tolerate a variety of conditions. They thrive in nearly any water source with abundant aquatic vegetation. Red-eared sliders can eat a variety of aquatic plants as well as tadpoles, crustaceans, fish, and insects.
In Arizona, they have been introduced to several areas, likely due to the accidental or intentional release of pet turtles by humans. Areas with invasive red-eared sliders include protected habitats like the Montezuma Well, a natural limestone sinkhole home to several endemic invertebrate and algae species found nowhere else in the world. At this water source, Sonora mud turtles are the only native turtle inhabitants. As such, introduced red-eared sliders — much larger, more omnivorous, and more prolific breeders than other Arizona aquatic turtles — can outcompete native species, leading to population declines that were mitigated following extensive removal efforts.
Other conservation strategies to remove invasive red-eared sliders in Arizona include trapping and removing non-native turtles from the Phoenix Zoo pond. Over 971 individuals have been captured in that area alone, with females then relocated to facilities where they can be adopted as captive pets again.
While campaigns to promote invasive species removals and responsible pet turtle ownership have had some successes, continued vigilance to reduce the release of red-eared sliders into the wild remains important for the future conservation of native turtles.
3) Alligator snapping turtle (Macrochelys temminckii)
- Family: Chelydridae
- Other names: Loggerhead snapper
- Average adult length: 15 – 26 in (38.1 – 66 cm)
- Conservation status: IUCN vulnerable, ESA not listed, Arizona state not listed
Often associated with the common snapping turtle (Chelydra serpentina), the alligator snapping turtle is actually a fairly distant relative with many distinct morphological features. They are much larger than common snapping turtles — in fact, they are the largest freshwater turtle in North America. Record alligator snapping turtle weights have exceeded 250 pounds, though they more regularly weigh between 35 – 150 pounds as adults.
Their common name derives from their alligator-like appearance, with a huge head, hooked beak, and prominent dorsal keels. The shell is usually gray, brown, or olive and rough in texture, with a very long tail. Their native range includes the rivers and streams that flow into the Gulf of Mexico, with their westernmost range in eastern Texas and Oklahoma. Alligator snapping turtles are opportunistic carnivores, consuming fish, amphibians, snakes, invertebrates, water birds, small mammals, other turtles, and occasionally carrion or aquatic plants.
Due to overharvesting for the exotic pet trade and for its meat, alligator snapping turtles are protected in some states and have been recently proposed for listing under the Endangered Species Act. In areas outside its native range, however, the alligator snapping turtle has occasionally escaped or been intentionally released, with a 62-pound individual captured near the Phoenix Zoo. They have been previously captured in the Lower Salt River near Phoenix as well as in the Imperial Reservoir on the California-Arizona border, but such events are relatively uncommon. Nonetheless, due to their capacity for consuming or outcompeting other turtles and native species, the possession of both alligator and common snapping turtles in captivity is prohibited by Arizona state law.
4) Texas spiny softshell (Apalone spinifera emoryi)
- Family: Trionychidae
- Other names: None
- Average adult length: 7 – 17 in (17.8 – 43.2 cm) females; 5 – 9.3 in (12.7 – 23.6 cm) males
- Conservation status: IUCN least concern, ESA not listed, Arizona state not listed
Often described as “animated pancakes”, softshell turtles are defined by soft leathery shells devoid of scales or scutes. They are agile in the water and on land, but are closely tied to aquatic habitats. A subspecies of the spiny softshell turtle (A. spinifera), the native range of the Texas spiny softshell includes the Pecos River and the Rio Grande. It has been introduced to the lower Colorado River basin area, likely beginning in the early 1900s, and has since spread to many lowland areas of California as well as the Gila River area in Arizona.
Like other spiny softshell turtles, they are primarily olive-gray or yellowish-brown in color, with tiny projections on the entire carapace surface that resemble spines. The carapace pattern has white spots, present only on the posterior third region and not ringed with black, which distinguishes them from other spiny softshell subspecies. The tubercles, that is, the “warts” on the front edge of the shell, are rounded and either not prominent or absent. These tubercles are unique from all other spiny softshell turtles except the Guadalupe spiny softshell (A. s. guadalupensis), which is not typically found in Arizona and usually has black spots on the carapace.
Spiny softshell turtles are habitat generalists and can be found in freshwater such as ponds, rivers, lakes, and streams, including very shallow water. Their diet includes aquatic crustaceans and insects as well as fish, algae, and plants, with hunting strategies including ambushing as well as active hunting.
Unlike most other turtles, hatchling sex is primarily determined by genetics rather than temperature, though interactions between chromosome protein expression and temperature may influence sex ratios. This reproductive strategy may offer a buffer against high predation and low hatchling survival. In areas where these turtles are invasive, they can outcompete native species for food and basking areas, and therefore are included among turtles without possession or bag limits in open areas in Arizona (though a valid fishing license is always required for harvesting softshell turtles).
