Narrow-headed garter snake

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Narrow-headed garter snake
Status TNC G3.svg
Vulnerable  (NatureServe)
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Order: Squamata
Suborder: Serpentes
Family: Colubridae
Genus: Thamnophis
Species:
T. rufipunctatus
Binomial name
Thamnophis rufipunctatus
(Cope, 1875) [2]
Synonyms
  • Chilopoma rufipunctatumCope, 1875
  • Atomarchus multimaculatusCope, 1883
  • Eutaenia multimaculata
    – Cope, 1886
  • Thamnophis rufipunctatus
    – Stebbins, 1985
  • Nerodia rufipunctatus
    – Chiasson & Lowe, 1989
  • Thamnophis rufipunctatus
    – Rossman et al., 1996 [3]

The narrow-headed garter snake, Thamnophis rufipunctatus, is a species of nonvenomous garter snake that is endemic to the southwestern United States. Its common names also include narrowhead garter snake and narrowhead watersnake.

Contents

Taxonomy

Chiasson and Lowe (1989) suggested the species be included in the genus Nerodia (watersnakes) due to its highly aquatic nature, however, this classification was later rejected based on genetic data. [4]

The Madrean narrow-headed garter snake [5] and Southern Durango spotted garter snake were at times considered subspecies of the narrow-headed garter snake, but are now given full species status based on genetic analysis. [6] [7] [8]

Etymology

The scientific name Thamnophis rufipunctatus is a combination of Ancient Greek and New Latin that means "bush snake punctuated with red". The generic name Thamnophis is derived from the Greek "thamnos" (bush) and "ophis" (snake) and the specific name rufipunctatus is derived from the New Latin "rufi-" (red) and "punctatus" (punctuated), referring to the snake's reddish-brown spots.

Geographic range

It is found in Arizona and New Mexico at or near the Mogollon Rim, mainly in canyon-bound headwaters of the Gila and San Francisco rivers and their tributaries. [3]

It is not thought to occur in Mexico. [9] Populations in Mexico that were previously considered subspecies of Thamnophis rufipunctatus are now reclassified as separate species.

Description

The snake is blue-grey to olive-grey, or greenish to brown, and it has brown, orange, or black spots on the back. The total length of adults is 81–112 cm (32–44 in) (about 81–112 cm). Its most notable feature is its long, narrow snout, resulting in a rather triangular-shaped head.

It has eight or 9 upper labial scales, one of which enters the eye, two or three preocular scales, two to four postoculars, and one anterior temporal scale. The keeled dorsal scales are arranged in 21 rows at midbody. Ventrals number 152–177; the anal plate is entire; the subcaudals number 65–87, and are divided. [10]

Habitat and behavior

It is found near river banks or streams at higher elevations (2,300 to 8,000 ft (701 to 2,430 m)), and prefers clear, rocky streams with pool and riffle habitat, though it has also been observed at lake shorelines. [9] It is one of the most aquatic of all garter snakes. [1]

Narrow-headed garter snakes hibernate between October or November to March in rocky outcroppings above the flood line. [9] [11] They are viviparous and give birth to 4-17 young in late July or August. They are sexually mature at around 2 years. [9]

They are often found underwater, and primarily forage on the bottom of streams. They can also be found perched in vegetation near the water, or basking near the water. They are capable of holding their breath for several minutes. [12]

Diet

These snakes are piscivorous, meaning they primarily eat fish. Their diet includes dace, chub, sucker, and both native and introduced trout. They have been reported to eat tadpoles and salamanders, but these are based on historical captive reports and not likely a common part of their diet. [9] [11]

Unlike other garter snakes, they are ambush predators, and will sit and wait for prey to approach. [13] Due to their unique mass, the specific gravity of the snake in water is 1, meaning they neither sink nor float and can maintain their position in the water. [9]

Conservation

The snake's population has declined significantly within its range.

In 2007, the International Union for Conservation of Nature (IUCN) classified it as Least Concern because of its wide range and presumably large population (which included Mexican populations now classified as different species). [1] NatureServe currently lists it as G3 - Vulnerable. [14]

In 2014, the species was listed as Threatened under the Endangered Species Act. The FWS stated that population densities had notably declined and the snake was found in only 5 of 16 historical locations, though its status on tribal lands was unknown. [9]

The main reasons for threatened status are the decline of river habitats, nonnative predatory fish such as brown trout which compete with the narrow-headed garter snake for prey, and nonnative crayfish and bullfrogs which both compete with the snake for prey as well as prey on juvenile snakes. Additional threats include poisons intended to eliminate invasive species, drought, catastrophic wildfires, and possibly factors such as disease, siltation, killing and collection by humans, and overgrazing. [9] [12]

In 2018, the Center for Biological Diversity sued the U.S. Fish and Wildlife Service for failing to implement proposed critical habitat after the species was listed as threatened. [15] In October, 2021, the FWS designated 23,785 acres of critical habitat for the narrow-headed garter snake, including 447 miles of streams. [16] This was significantly less than the over 420,000 acres originally proposed in 2013. In August 2023, the Center for Biological Diversity again sued the government for reducing the snake's habitat. [17]

Related Research Articles

<span class="mw-page-title-main">Garter snake</span> Common name for North American snakes of the genus Thamnophis

Garter snake is the common name for small to medium-sized snakes belonging to the genus Thamnophis in the family Colubridae. They are native to North and Central America, ranging from central Canada in the north to Costa Rica in the south.

<span class="mw-page-title-main">Common garter snake</span> Species of snake

The common garter snake is a species of snake in the subfamily Natricinae of the family Colubridae. The species is indigenous to North America and found widely across the continent. There are several recognized subspecies. Most common garter snakes have a pattern of yellow stripes on a black, brown or green background, and their average total length is about 55 cm (22 in), with a maximum total length of about 137 cm (54 in). The average body mass is 150 g (5.3 oz). The common garter snake is the state reptile of Massachusetts.

<i>Thamnophis saurita</i> Species of snake

Thamnophis saurita, also known as the eastern ribbon snake, common ribbon snake, or simply ribbon snake, is a common species of garter snake native to Eastern North America. It is a non-venomous species of snake in the subfamily Natricinae of the family Colubridae. The ribbon snake averages 16 to 35 inches in total length. It is dark brown with bright yellow stripes. The ribbon snake is not sexually dimorphic; however, females are normally thicker than their male counterparts.

<span class="mw-page-title-main">San Francisco garter snake</span> Subspecies of snake

The San Francisco garter snake is a slender multi-colored subspecies of the common garter snake. Designated as an endangered subspecies since the year 1967, it is endemic to San Mateo County and the extreme northern part of coastal Santa Cruz County in California.

<span class="mw-page-title-main">Eastern garter snake</span> Subspecies of snake

The eastern garter snake is a medium-sized snake indigenous to North America.

<span class="mw-page-title-main">Checkered garter snake</span> Species of snake

The checkered garter snake is a species of garter snake in the subfamily Natricinae of the family Colubridae. The species is endemic to the southwestern United States, Mexico, and Central America.

<span class="mw-page-title-main">Banded water snake</span> Species of snake

The banded water snake or southern water snake is a species of mostly aquatic, nonvenomous, colubrid snakes most commonly found in the Midwest, Southeastern United States.

<span class="mw-page-title-main">Plains garter snake</span> Species of snake

The plains garter snake is a species of garter snake native to most of the central United States as far north as Canada and as far south as Texas. It has a distinctive orange or yellow stripe from its head to tail, and the rest of its body is mainly a gray-green color. The snake is commonly found living near water sources such as streams and ponds, but can also be found in urban areas and vacant lots. Although the IUCN lists the species as "Least Concern", some states have given it their own special status. This species is mildly venomous, although the venom is not toxic to humans.

<span class="mw-page-title-main">Giant garter snake</span> Species of snake

The giant garter snake is the largest species of garter snake. Relatively rare, it is a semi-aquatic snake with a limited distribution in the wetlands of central California.

<span class="mw-page-title-main">Two-striped garter snake</span> Species of snake

The two-striped garter snake is a species of aquatic snake in the subfamily Natricinae of the family Colubridae. The species is endemic to western North America.

<span class="mw-page-title-main">Western terrestrial garter snake</span> Species of snake

The western terrestrial garter snake is a western North American species of colubrid snake. At least five subspecies are recognized.

<span class="mw-page-title-main">Blackneck garter snake</span> Species of snake

Thamnophis cyrtopsis, the blackneck garter snake, is a species of garter snake of the genus Thamnophis. It is native to the southwestern United States, Mexico and Guatemala, and can be found in a wide range of different habitats, often near water sources.

<span class="mw-page-title-main">Common watersnake</span> Species of snake

The common watersnake is a species of large, nonvenomous, common snake in the family Colubridae. The species is native to North America. It is frequently mistaken for the venomous cottonmouth.

<span class="mw-page-title-main">Shorthead garter snake</span> Species of snake

Thamnophis brachystoma, commonly known as the shorthead garter snake or short-headed gartersnake, is a small species of colubrid snake. The species is endemic to the north-eastern United States.

<span class="mw-page-title-main">California red-sided garter snake</span> Subspecies of snake

The California red-sided garter snake is a subspecies of the common garter snake. This slender subspecies of natricine snake is indigenous to North America and is one of three recognized subspecies of Thamnophis sirtalis found in California. While commonly confused with the subspecies T. s. concinnus, it is biologically part of the population of the subspecies T. s. tetrataenia, as pointed out by Boundy and Rossman (1995), but was preserved as T. s. infernalis as a neotype under ICZN code Article 75 in a 2000 decision by the International Commission on Zoological Nomenclature (ICZN) in 2000 in order to preserve the existing subspecies taxonomy.

<span class="mw-page-title-main">Blackbelly garter snake</span> Species of snake

The blackbelly garter snake is a species of snake of the family Colubridae. It is found in Mexico.

<span class="mw-page-title-main">Mexican garter snake</span> Species of snake

The Mexican garter snake is a species of snake of the family Colubridae. It is found in Mexico and in the United States. This harmless snake is semi-aquatic and most of the 10 recognized subspecies are restricted to lake basins in Mexico.

The Southern Durango spotted garter snake is a species of snake of the family Colubridae. It is endemic to the state of Durango, Mexico.

References

  1. 1 2 3 Hammerson, G.A. (2007). "Thamnophis rufipunctatus". IUCN Red List of Threatened Species . 2007: e.T63990A12727179. doi: 10.2305/IUCN.UK.2007.RLTS.T63990A12727179.en .
  2. ↑ ITIS (Integrated Taxonomic Information System). www.itis.gov.
  3. 1 2 Thamnophis rufipunctatus at the Reptarium.cz Reptile Database. Accessed 23 July 2016.
  4. ↑ de Queiroz, A., and R. Lawson (1994). "Phylogenetic relationships of the garter snakes based on DNA sequence and allozyme variation". Biological Journal of the Linnean Society . 53 (3): 209–229. doi: 10.1006/bijl.1994.1069 .{{cite journal}}: CS1 maint: multiple names: authors list (link)
  5. ↑ Dahms Tierleben. www.dahmstierleben.de.
  6. ↑ Wood, Dustin A. (2011). "Refugial isolation and divergence in the Narrowheaded Gartersnake species complex (Thamnophis rufipunctatus) as revealed by multilocus DNA sequence data". Molecular Ecology . 20 (18): 3856–3878. doi:10.1111/j.1365-294X.2011.05211.x. PMID   21851436.
  7. ↑ Thamnophis nigronuchalis at the Reptarium.cz Reptile Database . Accessed 23 July 2016.
  8. ↑ Flores-Villela, O. (2007). "Thamnophis nigronuchalis". IUCN Red List of Threatened Species . 2007: e.T63984A12726140. doi: 10.2305/IUCN.UK.2007.RLTS.T63984A12726140.en .
  9. 1 2 3 4 5 6 7 8 "Threatened Status for the Northern Mexican Gartersnake and Narrow-Headed Gartersnake; Final Rule" (PDF). Retrieved 2024-08-09.
  10. ↑ Smith, Hobart M., and Edmund D. Brodie, Jr. 1982. Reptiles of North America: A Guide to Field Identification. Golden Press. New York. 240 pp. ISBN   0-307-13666-3.(Thamnophis, p. 144; Thamnophis rufipunctatus, pp. 152-153.)
  11. 1 2 Thomas C. Brennan (2008). "NARROW-HEADED GARTERSNAKE Thamnophis rufipunctatus". Reptiles and Amphibians of Arizona. Retrieved 23 July 2016.
  12. 1 2 "Northern Arizona University" . Retrieved 2024-08-09.
  13. ↑ Brennan, T. C., and A. T. Holycross (2006). A field guide to amphibians and reptiles in Arizona. Phoenix, AZ: Arizona Game and Fish Department.{{cite book}}: CS1 maint: multiple names: authors list (link)
  14. ↑ "Thamnophis rufipunctatus" . Retrieved 2024-08-10.
  15. ↑ "Lawsuit Pushes Trump Administration to Protect Arizona, New Mexico Snakes" . Retrieved 2024-08-10.
  16. ↑ "Imperiled, Fish-Eating Snake Gains 447 Miles of Protected Streams in Arizona, New Mexico" . Retrieved 2024-08-10.
  17. ↑ "Lawsuit Challenges Massive Habitat Reduction for Endangered Snakes in Arizona, New Mexico" . Retrieved 2024-08-10.
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