|Coluber constrictor anthicus, |
The eastern racer (Coluber constrictor) is a species of nonvenomous snake in the family Colubridae. The species is endemic to North America and Central America. Eleven subspecies, including the nominotypical subspecies, are recognized, which as a group are commonly referred to as the eastern racers. The species is monotypic in the genus Coluber.
Adult eastern racers can typically vary from 50 to 152 cm (20 to 60 in) in total length (including tail) depending on the subspecies, but a record-sized specimen measured 185.4 cm (73.0 in) in total length. A typical adult specimen will weigh around 556 g (1.226 lb), with little size difference between the sexes. The patterns vary widely among subspecies. Most are solid-colored as their common names imply: black racers, brown racers, tan racers, blue racers, or green racers. "Runner" is sometimes used instead of "racer" in their common names. All subspecies have a lighter-colored underbelly: white, light tan, or yellow in color. Juveniles are more strikingly patterned, with a middorsal row of dark blotches on a light ground color. The tail is unpatterned. As they grow older, the dorsum darkens and the juvenile pattern gradually disappears.
The eastern racers are fast-moving, highly active, diurnal snakes. Their diet consists primarily of small rodents, frogs, toads, lizards, and other snakes. Some subspecies are known to climb trees to eat eggs and young birds. Juveniles often consume soft-bodied insects, such as crickets and moths. Despite their specific name, constrictor, they do not really employ constriction, instead simply subduing struggling prey by pinning it bodily, pressing one or two coils against it to hold it in place instead of actually suffocating it. Most smaller prey items are simply swallowed alive.
They are curious snakes with excellent vision and are sometimes seen raising their heads above the height of the grass where they are crawling to view what is around them. Aptly named, racers are very fast and typically flee from a potential predator. However, once cornered, they put up a vigorous fight, biting hard and often. They are difficult to handle and will writhe, defecate, and release a foul-smelling musk from their cloacae. Vibrating their tails among dry leaves, racers can sound convincingly like rattlesnakes.
C. constrictor is found frequently near water, but also in brush, trash piles, roadsides, and swamps, and in suburbia; it is the most common snake in residential neighborhoods in Florida. It spends most of its time on the ground, but it is a good tree climber and may be found in shrubs and trees where bird nests can be raided for eggs and chicks, as well as small adult birds such as finches, canaries, and thrashers.
Most of the eastern racers prefer open, grassland-type habitats where their keen eyesight and speed can be readily used, but they are also found in light forest and even semiarid regions. They are usually not far from an area of cover for hiding.
In C. constrictor, mating takes place in the spring from April until early June. Around a month later, the female lays three to 30 eggs in a hidden nest site, such as a hollow log, an abandoned rodent burrow, or under a rock. The juveniles hatch in the early fall. A newborn is 8-10 in (20–26 cm) in total length. Maturity is reached around 2 years old. Eastern racers have been known to lay their eggs in communal sites, where a number of snakes, even those from other species, all lay their eggs together.
- Coluber constrictor anthicus (Cope, 1862) – buttermilk racer
- Coluber constrictor constrictor Linnaeus, 1758 – northern black racer
- Coluber constrictor etheridgei Wilson, 1970 – tan racer
- Coluber constrictor flaviventris Say, 1823 – eastern yellow-bellied racer
- Coluber constrictor foxii (Baird & Girard, 1853) – blue racer
- Coluber constrictor helvigularis Auffenberg, 1955 – brown-chinned racer
- Coluber constrictor latrunculus Wilson, 1970 – black-masked racer
- Coluber constrictor oaxaca (Jan, 1863) – Mexican racer
- Coluber constrictor paludicola Auffenberg & Babbitt, 1955 – Everglades racer
- Coluber constrictor priapus Dunn & Wood, 1939 – southern black racer
- Coluber constrictor mormon (Baird & Girard, 1852) – western yellow-bellied racer
Adult black rat snake, Elaphe obsoleta obsoleta, often confused with the northern black racer
- Hammerson, G.A.; Acevedo, M.; Ariano-Sánchez, D.; Johnson, J. (2013). "Coluber constrictor". IUCN Red List of Threatened Species. 2013: e.T63748A3128579. doi:10.2305/IUCN.UK.2013-2.RLTS.T63748A3128579.en. Retrieved 10 October 2020.
- Stejneger L, Barbour T (1917). A Check List of North American Amphibians and Reptiles. Cambridge, Massachusetts: Harvard University Press. 125 pp. (Coluber constrictor, p. 79)
- "Coluber constrictor ". The Reptile Database. www.reptile-database.org.
- Conant, Roger (1975). A Field Guide to Reptiles and Amphibians of Eastern and Central North America, Second Edition. Boston: Houghton Mifflin. xviii + 429 pp. + Plates 1-48. ISBN 0-395-19977-8 (paperback). (Coluber consrictor constrictor, pp. 178-179 + Plate 26 + Map 139).
- "Species profile: Minnesota DNR". Dnr.state.mn.us. Retrieved 31 May 2013.
- "Southern Black Racer, Racer (Florida Museum)". Flmnh.ufl.edu. Retrieved 31 May 2013.
- Carfagno, Gerardo L. F. (2007). Habitat Use and Thermal Ecology of Ratsnakes (Elaphe Obsoleta) and Racers ... - Gerardo L. F. Carfagno - Google Books. ISBN 9780549341376. Retrieved 31 May 2013.
- "Corkscrew's common snakes: Black Racer (Coluber constrictor priapus)". Corkscrew Swamp Sanctuary. Retrieved 31 May 2013.
- School of Computer Science. "UMass Amherst: The College of Natural Sciences". Umass.edu. Retrieved 31 May 2013.
- "5.031 State reptile". LAWriter: Ohio Laws and Rles. Lawriter LLC. 2008. Retrieved 22 January 2011.
- Eastern and Western Yellow-bellied Racers, COSEWIC Assessment and Update Status Report
- Coluber Constrictor, The IUCN Red List of Threatened Species.
- "Black Snakes": Identification and Ecology - University of Florida fact sheet.
- Coluber constrictor, University of Michigan, Animal Diversity Web.
- Racer, Reptiles and Amphibians of Iowa.
- Species Coluber constrictor at The Reptile Database
- Encyclopedia Americana. 1920. .
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- Behler, John L.; King, F. Wayne (1979). The Audubon Society Field Guide to North American Reptiles and Amphibians. New York: Alfred A. Knopf. 743 pp., 657 color plates. ISBN 0-394-50824-6. (Coluber constrictor, pp. 596–599 + Plates 468, 478, 480, 486).
- Boulenger GA (1893). Catalogue of the Snakes in the British Museum (Natural History). Volume I., Containing the Families ... Colubridæ Aglyphæ, part. London: Trustees of the British Museum (Natural History). (Taylor and Francis, printers). xiii + 448 pp. + Plates I-XXVIII. (Zamenis constrictor, pp. 387–388).
- Conant, Roger; Bridges, William (1939). What Snake Is That?: A Field Guide to the Snakes of the United States East of the Rocky Mountains. (with 108 drawings by Edmond Malnate). New York and London: D. Appleton-Century Company. Frontispiece map + viii + 163 pp. + Plates A-C, 1-32. (Coluber constrictor, pp. 44–47 + Plate 5, figure 15; Plate 6, figure 16).
- Goin, Coleman J.; Goin, Olive B.; Zug, George R. (1978). Introduction to Herpetology, Third Edition. San Francisco: W.H. Freeman and Company. xi + 378 pp. ISBN 0-7167-0020-4. (Coluber constrictor, pp. 122–123, 322-323).
- Linnaeus C (1758). Systema Naturæ per regna tria naturæ, secundum classes, ordines, genera, species, cum characteribus, diferentiis, synonymis, locis. Tomus I. Editio Decima, Reformata. Stockholm: L. Salvius. 824 pp. (Coluber constrictor, new species, p. 216). (in Latin).
- Morris, Percy A. (1948). Boy's Book of Snakes: How to Recognize and Understand Them. (A volume of the Humanizing Science Series, edited by Jaques Cattell). New York: Ronald Press. viii + 185 pp. (Coluber constrictor, pp. 37–41, 179).
- Powell R, Conant R, Collins JT (2016). Peterson Field Guide to Reptiles and Amphibians of Eastern and Central North America, Fourth Edition. Boston and New York: Houghton Mifflin Harcourt. xiv + 494 pp. , 47 plates, 207 Figures. ISBN 978-0-544-12997-9. (Coluber constrictor, pp. 368–370, Figure 176 + Plate 32).
- Schmidt, Karl P.; Davis, D. Dwight (1941). Field Book of Snakes of the United States and Canada. New York: G.P. Putnam's Sons. 365 pp. (Coluber constrictor, pp. 125–126 + Plates 4, 13).
- Smith, Hobart M.; Brodie, Edmund D. Jr. (1982). Reptiles of North America: A Guide to Field Identification. New York: Golden Press. 240 pp. ISBN 0-307-13666-3 (paperback), ISBN 0-307-47009-1 (hardcover). (Coluber constrictor, pp. 190–191).
- Stebbins RC (2003). A Field Guide to Western Reptiles and Amphibians, Third Edition. The Peterson Field Guide Series ®. Boston and New York: Houghton Mifflin Company. xiii + 533 pp. ISBN 978-0-395-98272-3. (Coluber constrictor, pp. 351–352 + Plate 43 + Map 141).
- Wright, Albert Hazen; Wright, Anna Allen (1957). Handbook of Snakes of the United States and Canada. Ithaca and New York: Comstock Publishing Associates, a division of Cornell University Press. 1,105 pp. (in 2 volumes). (Coluber constrictor, pp. 131–152, Figures 42-47, Map 17).
- Zim HS, Smith HM (1956). Reptiles and Amphibians: A Guide to Familiar American Species: A Golden Nature Guide. New York: Simon and Schuster. 160 pp. (Coluber constrictor, pp. 85, 156).