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Rena humilis

Baird and Girard, 1853

Western Threadsnake

G5Secure Found in 6 roadless areas NatureServe Explorer →
G5SecureGlobal Rank
Least concernIUCN
LowThreat Impact
Identity
Unique IDELEMENT_GLOBAL.2.105688
Element CodeARADD01020
Record TypeSPECIES
ClassificationSpecies
Classification StatusStandard
Name CategoryVertebrate Animal
IUCNLeast concern
Endemicoccurs (regularly, as a native taxon) in multiple nations
KingdomAnimalia
PhylumCraniata
ClassReptilia
OrderSquamata
FamilyLeptotyphlopidae
GenusRena
Synonyms
Leptotyphlops humilis(Baird and Girard, 1853)
Other Common Names
Western Blind Snake (EN) western threadsnake (EN)
Concept Reference
Collins, J. T. 1990. Standard common and current scientific names for North American amphibians and reptiles. 3rd ed. Society for the Study of Amphibians and Reptiles. Herpetological Circular No. 19. 41 pp.
Taxonomic Comments
This species formerly was included in the genus Leptotyphlops. Adalsteinsson et al. (2009) examined DNA sequences (from nine mitochondrial and nuclear genes) of 91 individuals representing 34 recognized species of the famikly Leptotyphlopidae. Based on these analyses, they presented a revised classification of the family. The leptotyphlopid species occurring in North America north of Mexico (dissecta, dulcis, humilis) were removed from the genus Leptotyphlops and placed in the genus Rena, the range of which extends southward through Middle and South America to Uruguay and Argentina.
Conservation Status
Review Date2006-08-28
Change Date1996-10-31
Edition Date2006-08-28
Edition AuthorsHammerson, G.
Threat ImpactLow
Range Extent200,000-2,500,000 square km (about 80,000-1,000,000 square miles)
Number of Occurrences81 to >300
Range Extent Comments
Range extends from southern California, southern Nevada, and southwestern Utah south through Arizona, southern New Mexico, and western Texas to southern Baja California (including several adjacent islands) and Colima (Mexico), at elevations from below sea level in desert sinks to around 1,520 meters (5,000 feet) (Degenhardt et al. 1996, Tennant 1998, Werler and Dixon 2000, Grismer 2002, Stebbins 2003).
Occurrences Comments
This species is represented by a large number of occurrences (subpopulations). Werler and Dixon (2000) mapped about 50 collection sites in Texas. Degenhardt et al. (1996) mapped 16 collection sites in New Mexico. This snake is "ubiquitous" in Bja California (Grismer 2002).
Threat Impact Comments
No major threats are known.
Ecology & Habitat

Habitat

Habitats range from deserts and desert-grasslands to brush-covered mountain slopes, including rocky hillsides, canyon bottoms or washes near stream courses, riparian zones, areas near springs, sandy areas above ocean beaches, and sometimes gardens and farmland (Werler and Dixon 2000, Stebbins 2003). This secretive, fossorial snake sometimes can be found under rocks, wood, or debris, among plant roots, or in crevices, often in loose damp soil.

Reproduction

Lays clutch of 2-6 eggs, July-August (Stebbins 1985). Females may stay with eggs after hatching. May nest communally (Behler and King 1979).
Terrestrial Habitats
Woodland - MixedShrubland/chaparralGrassland/herbaceousDesertSand/duneCropland/hedgerowSuburban/orchard
Palustrine Habitats
Riparian
Other Nations (1)
United StatesN5
ProvinceRankNative
ArizonaS5Yes
UtahS3Yes
New MexicoS3Yes
Navajo NationS3Yes
TexasS5Yes
NevadaS4Yes
CaliforniaSNRYes
Roadless Areas (6)
Arizona (4)
AreaForestAcres
Black CrossTonto National Forest5,966
GoldfieldTonto National Forest15,257
Middle Romero WSRCoronado National Forest60
PinalenoCoronado National Forest130,920
California (2)
AreaForestAcres
Cactus Springs BSan Bernardino National Forest3,106
Eagle PeakCleveland National Forest6,481
References (17)
  1. Adalsteinsson, S. A., W. R. Branch, S. Trape, L. J. Vitt, and S. B. Hedges. 2009. Molecular phylogeny, classification, and biogeography of snakes of the family Leptotyphlopidae (Reptilia, Squamata). Zootaxa 2244:1-50.
  2. Behler, J. L., and F. W. King. 1979. The Audubon Society field guide to North American reptiles and amphibians. Alfred A. Knopf, New York. 719 pp.
  3. Collins, J. T. 1990. Standard common and current scientific names for North American amphibians and reptiles. 3rd ed. Society for the Study of Amphibians and Reptiles. Herpetological Circular No. 19. 41 pp.
  4. Conant, R. and J. T. Collins. 1991. A field guide to reptiles and amphibians: eastern and central North America. Third edition. Houghton Mifflin Co., Boston, Massachusetts. 450 pp.
  5. Crother, B. I. (editor). 2008. Scientific and standard English names of amphibians and reptiles of North America north of Mexico, with comments regarding confidence in our understanding. Sixth edition. Society for the Study of Amphibians and Reptiles Herpetological Circular 37:1-84. Online with updates at: http://www.ssarherps.org/pages/comm_names/Index.php
  6. Crother, B. I. (editor). 2012. Scientific and standard English names of amphibians and reptiles of North America north of Mexico, with comments regarding confidence in our understanding. 7th edition. SSAR Herpetological Circular 39:1-92.
  7. Crother, B. I. (editor). 2017. Scientific and standard English names of amphibians and reptiles of North America north of Mexico, with comments regarding confidence in our understanding. 8th edition. SSAR Herpetological Circular 43:1-104. [Updates in SSAR North American Species Names Database at: https://ssarherps.org/cndb]
  8. Degenhardt, W. G., C. W. Painter, and A. H. Price. 1996. Amphibians and reptiles of New Mexico. University of New Mexico Press, Albuquerque. xix + 431 pp.
  9. Ernst, C. H., and E. M. Ernst. 2003. Snakes of the United States and Canada. Smithsonian Books, Washington, D.C.
  10. Grismer, L. L. 2002. Amphibians and reptiles of Baja California including its Pacific islands and islands in the Sea of Cortes. University of California Press, Berkeley. xiii + 399 pp.
  11. Hahn, D. E. 1979. Leptotyphlops humilis. Cat. Am. Amph. Rep. 232.1-232.4.
  12. Slevin, J. R. 1950. A remarkable concentration of desert snakes. Herpetologica 6:12-13.
  13. Stebbins, R. C. 1985a. A field guide to western reptiles and amphibians. Second edition. Houghton Mifflin Company, Boston, Massachusetts. xiv + 336 pp.
  14. Stebbins, R. C. 2003. A field guide to western reptiles and amphibians. Third edition. Houghton Mifflin Company, Boston.
  15. Tennant, A. 1984. The Snakes of Texas. Texas Monthly Press, Austin, Texas. 561 pp.
  16. Tennant, A. 1998. A field guide to Texas snakes. Second edition. Gulf Publishing Company, Houston, Texas.
  17. Turner, F. B., and R. H. Wauer. 1963. A survey of the herpetofauna of the Death Valley area. Great Basin Naturalist 23:199-18.