Masticophis flagellum is found is found in the southern half of the U.S., and the northern 2/3rds of Mexico (King 1979).

Biogeographic Regions: nearctic (Native )

occurs (regularly, as a native taxon) in multiple nations

United States

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

Global Range: (>2,500,000 square km (greater than 1,000,000 square miles)) The large range extends from the Atlantic coast to the Pacific coast; northern California, Nevada, southwestern Utah, eastern Colorado, southwestern Nebraska, Missouri, . North to central California and Nevada, southwestern Utah, Nebraska, Missouri, Kentucky (formerly), and North Carolina south to southern Baja California, Sinaloa, Queretaro, Gulf Coast of United States, and southern Florida (Wilson 1973).

This is a long, slender snake with smooth scales. The dorsal coloration in the adult varies from shades of tan, grey, pink, and red. Thin, white crossbars or blotches are found on the dorsal area behind the black or brown neck. The ventral surface is usually a tan to pinkish. Juveniles have tan, brown, or black transverse bands. In hatchlings the black neck is absent. The adult length ranges from 91.4-259 cm. The large eyes have round pupils, and are protected by supraocular scales. It has 17 dorsal scale rows at midbody, and a divided anal plate.(King 1979)

Length: 259 cm

• Terrestrial

Open hillsides, dry sand, prairies, oak and pine woodlands, grassy areas, dunes, and scrub. Not found above 2150m altitude (King 1979, Stebbins 1985)

Terrestrial Biomes: desert or dune ; savanna or grassland ; chaparral ; forest

Comments: This snake occurs in a wide range of habitats: desert, prairie, scrubland, juniper-grassland, woodland, thornforest, farmland, creek valleys, and sometimes swamps; usually in relatively dry open terrain. It is terrestrial but also climbs into vegetation. It seeks cover in burrows, among rocks, or in vegetation.

Non-Migrant: No. All populations of this species make significant seasonal migrations.

Locally Migrant: No. No populations of this species make local extended movements (generally less than 200 km) at particular times of the year (e.g., to breeding or wintering grounds, to hibernation sites).

Locally Migrant: No. No populations of this species make annual migrations of over 200 km.

Preys on birds, rodents, lizards, other snakes(including rattlesnakes), small turtles, bird eggs, and insects. It hunts with its head raised above the ground, and will eat several small rodents during one feeding. It feeds approximately every five days. (Barker 1964)

Comments: Eats lizards, snakes, birds and their eggs, small mammals, insects, and carrion (Stebbins 1985).

Note: For many non-migratory species, occurrences are roughly equivalent to populations.

Estimated Number of Occurrences: > 300

Comments: This species is represented by very many occurrences or subpopulations. Wilson (1973) mapped hundreds of collection sites over a vast area.

100,000 to >1,000,000 individuals

Comments: Total adult population size is unknown but certainly exceeds 100,000. This species is common in Mexico and in many areas of the southern United States.

In the eastern Mojave Desert, California, activity range of six individuals averaged 53 ha; individuals moved on 76% on the days monitored; moved an average of 186 m per day (Secor 1995).

Comments: Active from April to October in north (Hammerson 1982), mid-March to late October in Texas (Tennant 1984).

Average lifespan

Status: captivity: 20.2 years.

In the M. flagellum reproduces once per year. Mating occurs in the spring, and females lay a clutch of 4-16 eggs in June or July. The young hatch from the granular-surfaced eggs in 6-11 weeks. Hatchlings are 30-40 cm long (King 1979, Stebbins 1985).

Lays clutch of 4-20 eggs, June-July. Eggs hatch in 6-11 weeks.

One subspecies, the San Joaquin whipsnake (Masticophis flagellum ruddocki) has been listed by the California Department of Fish and Game as a "Species of Special Concern" (California Dept. of Fish and Game 2001)

IUCN Red List of Threatened Species: least concern

United States

Rounded National Status Rank: N5 - Secure

Rounded Global Status Rank: G5 - Secure

Intrinsic Vulnerability: Moderately vulnerable

Global Short Term Trend: Relatively stable (=10% change)

Comments: Extent of occurrence, area of occupancy, number of subpopulations, and population size probably are relatively stable or declining at a rate of much less than 10% over 10 years or three generations.

Global Long Term Trend: Increase of 10-25% to decline of 30%

Comments: No major threats are known. This snake occurs in semiagricultural areas but generally not in areas with extensive, intensive cultivation (Hammerson 1999). Plastic netting such as used to exclude birds from fruit trees (and as components of erosion control blankets) is a potentially lethal entanglement hazard to this species and to other wildlife (Stuart et al. 2001).

Global Protection: Very many (>40) occurrences appropriately protected and managed

Comments: Many occurrences are in protected areas.

These are active, aggressive snakes, and will bite if handled. They are not venomous.

Coachwhips include pest rodents and venomous snakes in their diet.

Comments: Crother et al. (in Crother 2008) cited published studies in transferring all Masticophis species to the genus Coluber, but they also stated that there is unpublished evidence that would reject this. Pending publication of further data, we retain Masticophis as a valid genus.