Venomous snakes and spiders in Arizona

Arizona's venomous snakes are 13 rattlesnake species and one coral snake species. Together they account for 6,814 licensed records; the western diamondback rattlesnake alone has 26% of them, and the least recorded, the ridge-nosed rattlesnake, has 71.

Two widow species (Western black widow: 290 records, Brown widow: 2 records) and two recluse species (Arizona recluse: 7 records, Desert recluse: 7 records) are on the Arizona list. Widow bites cause muscle pain and cramps; recluse bites can cause a slow-healing wound. Both are rare and seldom fatal.

Yes. 21 scorpion species are recorded in Arizona, from 1,439 licensed records, the five most recorded: Arizona stripedtail scorpion (494 records), Arizona bark scorpion (266 records), Desert hairy scorpion (121 records), Yellow ground scorpion (74 records), Superstition Mountains scorpion (23 records). Every scorpion has venom; only the Arizona bark scorpion's sting is medically significant, and it is on the Arizona list.

Beyond the main list, eight scorpion species are known from Arizona by only 3 to 9 records each. Some are genuine rarities at the edge of their range; others may be strays, released pets or old misidentifications, so treat them as unconfirmed.

These eight account for 34% of all licensed snake records in Arizona; the most recorded, the gopher snake, alone for 7%.

These eight account for 21% of all licensed spider records in Arizona; the most recorded, the desert blond tarantula, alone for 7%.

Observation records of venomous snakes in Arizona run mostly April through September, peaking in August with 36% of them. December through February together hold under 2% of the records, so venomous snakes in Arizona are rarely recorded in winter.

Observation records of spiders in Arizona run mostly March through November, peaking in August with 22% of them. Winter (December to February) holds 7% of the records.

Observation records of scorpions in Arizona run mostly February through October, peaking in August with 21% of them. Winter (December to February) holds 8% of the records.

Cochise County has the most records of venomous snakes in Arizona, 1,777, most of them of the Mohave rattlesnake. Pima County and Maricopa County follow.

Pima County dominates: 27% of the state's licensed snake records come from it alone, and the top five counties hold 75%. 15 of Arizona's 15 counties have at least one licensed snake record.

Arizona counties with their own page: Apache County, Cochise County, Coconino County, Gila County, Graham County, Maricopa County, Mohave County, Pima County, Pinal County, Santa Cruz County, Yavapai County and Yuma County.

Yes. Arizona has 14 venomous snake species on its list, the kind people usually call poisonous: western diamondback rattlesnake, Mohave rattlesnake, sidewinder, black-tailed rattlesnake, Sonoran coralsnake, tiger rattlesnake, prairie rattlesnake, Arizona black rattlesnake, southwestern speckled rattlesnake, rock rattlesnake, twin-spotted rattlesnake, western rattlesnake, western massasauga and ridge-nosed rattlesnake. Strictly, snakes are venomous (they inject venom), not poisonous (harmful to eat or touch).

Yes. 13 species are on the Arizona list: the western diamondback rattlesnake, the Mohave rattlesnake, the sidewinder, the black-tailed rattlesnake, the tiger rattlesnake, the prairie rattlesnake, the Arizona black rattlesnake, the southwestern speckled rattlesnake, the rock rattlesnake, the twin-spotted rattlesnake, the western rattlesnake, the western massasauga and the ridge-nosed rattlesnake, with 6,455 licensed records between them. Most licensed records of the western diamondback rattlesnake come from Pima County, Cochise County and Maricopa County.

No. GBIF holds no copperhead record for Arizona under any license.

Not on our list: GBIF holds 1 cottonmouth record of any license in Arizona (northern cottonmouth 1), fewer than 10 of any one species; such records can be genuine rarities, strays, transported animals or misidentifications. Treat any snake that looks like a copperhead or cottonmouth as venomous.

Yes. One species is on the Arizona list: the Sonoran coralsnake, with 359 licensed records. Most licensed records of the Sonoran coralsnake come from Pima County, Cochise County and Maricopa County.

Arizona has 1,790 licensed records of the western diamondback rattlesnake, which ranks the state 2nd of the 7 states where it reaches our threshold. Its observation records in Arizona run mostly March through September, peaking in August; most licensed records come from Pima County, Cochise County and Maricopa County. Range in other states and photos: Western diamondback rattlesnake profile.

Arizona has 1,417 licensed records of the Mohave rattlesnake, which ranks the state 1st of the 6 states where it reaches our threshold. Its observation records in Arizona run mostly July through October, peaking in August; most licensed records come from Cochise County, Maricopa County and Pima County. Range in other states and photos: Mohave rattlesnake profile.

Arizona has 875 licensed records of the sidewinder, which ranks the state 2nd of the 4 states where it reaches our threshold. Its observation records in Arizona run mostly April through September, peaking in July; most licensed records come from Maricopa County, Pima County and Yuma County. Range in other states and photos: Sidewinder profile.

Arizona has 714 licensed records of the black-tailed rattlesnake, which ranks the state 1st of the 2 states where it reaches our threshold. Its observation records in Arizona run mostly April through September, peaking in August; most licensed records come from Cochise County, Pima County and Santa Cruz County. Range in other states and photos: Black-tailed rattlesnake profile.

Arizona has 359 licensed records of the Sonoran coralsnake, which ranks the state 1st of the 2 states where it reaches our threshold. Its observation records in Arizona run mostly May through October, peaking in July; most licensed records come from Pima County, Cochise County and Maricopa County. Range in other states and photos: Sonoran coralsnake profile.

Arizona has 335 licensed records of the tiger rattlesnake, the only state where it reaches our listing threshold. Its observation records in Arizona run mostly May through September, peaking in August; most licensed records come from Pima County, Maricopa County and Pinal County. Range in other states and photos: Tiger rattlesnake profile.

Arizona has 330 licensed records of the prairie rattlesnake, which ranks the state 7th of the 14 states where it reaches our threshold. Most of its licensed records in Arizona come from Coconino County, Apache County and Navajo County. Range in other states and photos: Prairie rattlesnake profile.

Arizona has 225 licensed records of the Arizona black rattlesnake, which ranks the state 1st of the 2 states where it reaches our threshold. Its observation records in Arizona run mostly April through September, peaking in August; most licensed records come from Yavapai County, Pima County and Gila County. Range in other states and photos: Arizona black rattlesnake profile.

Arizona has 186 licensed records of the southwestern speckled rattlesnake, which ranks the state 2nd of the 4 states where it reaches our threshold. Most of its licensed records in Arizona come from Maricopa County, Mohave County and Yavapai County. Range in other states and photos: Southwestern speckled rattlesnake profile.

Arizona has 161 licensed records of the rock rattlesnake, which ranks the state 2nd of the 3 states where it reaches our threshold. Its observation records in Arizona run mostly July through September, peaking in August; most licensed records come from Cochise County, Santa Cruz County and Pima County. Range in other states and photos: Rock rattlesnake profile.

Arizona has 152 licensed records of the twin-spotted rattlesnake, the only state where it reaches our listing threshold. Most of its licensed records in Arizona come from Cochise County, Graham County and Santa Cruz County. Range in other states and photos: Twin-spotted rattlesnake profile.

Arizona has 119 licensed records of the western rattlesnake, which ranks the state 7th of the 9 states where it reaches our threshold. Most of its licensed records in Arizona come from Coconino County, Mohave County and Apache County. Range in other states and photos: Western rattlesnake profile.

Arizona has 80 licensed records of the western massasauga, which ranks the state 4th of the 8 states where it reaches our threshold. Most of its licensed records in Arizona come from Cochise County. Range in other states and photos: Western massasauga profile.

Arizona has 71 licensed records of the ridge-nosed rattlesnake, which ranks the state 1st of the 2 states where it reaches our threshold. Most of its licensed records in Arizona come from Cochise County, Santa Cruz County and Pima County. Range in other states and photos: Ridge-nosed rattlesnake profile.

Many snakes and spiders taken for venomous ones are harmless species with a similar look. These are the usual confusions, with each species' licensed records in Arizona.

No copperheads reach the Arizona list, and GBIF holds no copperhead record for Arizona under any license, so a snake taken for one here is most likely a harmless lookalike. Those recorded in the state: eastern milksnake (10).

Cottonmouths are not on the Arizona list, but they are recorded in Arizona once (records of any license: northern cottonmouth 1): treat any snake like this as venomous until identified. Harmless species often taken for them in the state: southern watersnake (119).

Rattlesnakes: 6,455 licensed records in Arizona. Harmless species often taken for them are also on the state list: gopher snake (1,413) and plains hog-nosed snake (72). Together they have 1,485 licensed records, and here the venomous species are the more recorded side, 4.3 to 1.

Coral snakes: 359 licensed records in Arizona. Harmless species often taken for them are also on the state list: long-nosed snake (1,385), Sonoran mountain kingsnake (149) and eastern milksnake (10). Together they have 1,544 licensed records, and the lookalikes are recorded 4 times as often.

By count of venomous snake species, Arizona ranks 1st of 50 states. Nationally, Arizona leads with 14 species; five list none.

Arizona lists more venomous snake species than any state it borders (Arizona: 14 species; New Mexico 10, California 7, Nevada 6, Utah 5, Colorado 3).

Venomous snakes listed next door but not in Arizona: the Panamint rattlesnake (California and Nevada); the eastern black-tailed rattlesnake (New Mexico); the red diamond rattlesnake (California). Listed in Arizona but in none of its neighbors: the tiger rattlesnake and the twin-spotted rattlesnake. The most widely shared are the Mohave rattlesnake and the western rattlesnake, each listed in four of the five bordering states.

Yes. Two widow species are on the Arizona list: the western black widow (290 records) and the brown widow (2 records).

Not on our list: GBIF holds 2 brown recluse records of any license in Arizona (brown recluse 2), fewer than 10 of any one species; such records can be genuine rarities, strays, transported animals or misidentifications. Treat any spider that looks like a recluse as venomous. Other recluse species on the Arizona list: the Arizona recluse and the desert recluse.

Arizona has 290 licensed records of the western black widow, which ranks the state 2nd of the 18 states where it reaches our threshold. Its observation records in Arizona run mostly March through November, peaking in August; most licensed records come from Pima County, Coconino County and Maricopa County. Range in other states and photos: Western black widow profile.

Arizona has 7 licensed records of the Arizona recluse, the only state where it reaches our listing threshold.

Arizona has 7 licensed records of the desert recluse, which ranks the state 2nd of the 3 states where it reaches our threshold. Range in other states and photos: Desert recluse profile.

Arizona has 2 licensed records of the brown widow, which ranks the state 11th of the 11 states where it reaches our threshold. Range in other states and photos: Brown widow profile.