Snakes and spiders in Yuma County, Arizona
Yuma County, home of Yuma, has 19 snake and 4 spider species on record, from 870 licensed snake and 41 spider records. Venomous species here: the sidewinder, the southwestern speckled rattlesnake, the western diamondback rattlesnake, the Mohave rattlesnake, the black-tailed rattlesnake and the western black widow.
Are there venomous snakes or spiders in Yuma County?
Yes. The sidewinder: 181 licensed records, 21% of all Arizona records of it. The southwestern speckled rattlesnake: 28 licensed records, 15% of all Arizona records of it. The western diamondback rattlesnake: 22 licensed records, 1% of all Arizona records of it. The Mohave rattlesnake: 14 licensed records, 1% of all Arizona records of it. The black-tailed rattlesnake: 6 licensed records, 1% of all Arizona records of it. The western black widow: 1 licensed record, 0% of all Arizona records of it.
What snakes are in Yuma County?
In all, 19 snake species are on the Yuma County list. The most recorded are the sidewinder (181), the southern watersnake (119) and the Colorado desert shovel-nosed snake (78). Yuma County holds more than half of all Arizona records of the southern watersnake.
| # | Species | Records | Share of Arizona records |
|---|---|---|---|
| 1 | Sidewinder venomous Crotalus cerastes | 181 | 21% |
| 2 | Southern watersnake Nerodia fasciata | 119 | 100% |
| 3 | Colorado desert shovel-nosed snake Chionactis annulata | 78 | 35% |
| 4 | Western threadsnake Rena humilis | 58 | 15% |
| 5 | Western ground snake Sonora semiannulata | 49 | 8% |
| 6 | Glossy snake Arizona elegans | 45 | 6% |
| 7 | Gopher snake Pituophis catenifer | 44 | 3% |
| 8 | Western shovel-nosed snake Sonora occipitalis | 40 | 21% |
| 9 | Spotted leaf-nosed snake Phyllorhynchus decurtatus | 34 | 9% |
| 10 | Coachwhip Masticophis flagellum | 33 | 5% |
| 11 | Southwestern speckled rattlesnake venomous Crotalus pyrrhus | 28 | 15% |
| 12 | Checkered garter snake Thamnophis marcianus | 27 | 5% |
| 13 | Western patch-nosed snake Salvadora hexalepis | 23 | 3% |
| 14 | Western diamondback rattlesnake venomous Crotalus atrox | 22 | 1% |
| 15 | California kingsnake Lampropeltis californiae | 20 | 8% |
| 16 | Mohave rattlesnake venomous Crotalus scutulatus | 14 | 1% |
| 17 | Long-nosed snake Rhinocheilus lecontei | 9 | 1% |
| 18 | Black-tailed rattlesnake venomous Crotalus molossus | 6 | 1% |
| 19 | Northern three-lined boa Lichanura orcutti | — | — |
What spiders are in Yuma County?
In all, 4 spider species are on the Yuma County list. The most recorded are the desert blond tarantula (4), the hirsute paradise spider (1) and the western black widow (1).
| # | Species | Records | Share of Arizona records |
|---|---|---|---|
| 1 | Desert blond tarantula Aphonopelma chalcodes | 4 | 1% |
| 2 | Hirsute paradise spider Habronattus hirsutus | 1 | 3% |
| 3 | Western black widow venomous Latrodectus hesperus | 1 | 0% |
| 4 | Western spotted orbweaver Neoscona oaxacensis | — | — |
What stands out in Yuma County
Species for which Yuma County holds a large share of all Arizona records: the southern watersnake, 100% (119 of 119); the Colorado desert shovel-nosed snake, 35% (78 of 223); the sidewinder, 21% (181 of 875); the western shovel-nosed snake, 21% (40 of 195); the western threadsnake, 15% (58 of 375); the southwestern speckled rattlesnake, 15% (28 of 186).
Common in Arizona, not on the Yuma County list
Among the snakes most recorded across Arizona, these do not reach the county list: the blackneck garter snake (758 statewide) and the western terrestrial garter snake (728 statewide). Few records here can mean the species is rare in the county, or that few people have looked.
Harmless lookalikes in Yuma County
Cottonmouths are not on the Arizona list, but GBIF holds 1 cottonmouth record of any license in Arizona (northern cottonmouth 1): treat any snake like this as venomous until identified. Harmless species often taken for them here: the southern watersnake. Rattlesnakes are on the county list, and so are harmless species often taken for them: the gopher snake. No coral snakes reach the county list, but the Sonoran coralsnake is on the Arizona list: treat any snake like it as venomous until identified. Harmless species often taken for them here: the long-nosed snake.
Yuma County among Arizona counties
By licensed snake records Yuma County ranks 8th of 15 Arizona counties with any.
Other Arizona counties with their own page: Pima County, Cochise County, Maricopa County, Pinal County, Santa Cruz County, Yavapai County, Coconino County and Graham County.
The whole state: venomous species in Arizona, all snakes, all spiders.
GBIF records read 2026-09-29. Listed: any license. Counted: CC0/CC BY only. How we count.