Bullsnake

The subspecific name, sayi, is in honor of American naturalist Thomas Say.Beolens, Bo; Watkins, Michael; Grayson, Michael (2011). The Eponym Dictionary of Reptiles. Baltimore: Johns Hopkins university Press. xiii + 296 pp. {{ISBN|978-1-4214-0135-5}}. (Pituophis catenifer sayi, p. 234).

In Mexico, bullsnakes are called cincuate (/sentli/; Náhuatl: corn, /coatl/; Náhuatl: snake).

They are known as bull snakes or bullsnakes because of the deep hissing/rumbling sound they make when nervous, which can be reminiscent of a bellowing bull, as well as their overall defensive display of rearing up like a rattlesnake and rattling their tail in leaves, all of which is a bluff; the snake is not venomous, and rarely bites.

The bullsnake (Pituophis catenifer sayi) occurs throughout the Great Plains and parts of the Midwestern United States, ranging from southern Saskatchewan, and Alberta, Canada south, into Nuevo León and Tamaulipas, Mexico. States in the US include Colorado, Illinois, Indiana, Iowa, Kansas, Minnesota, Missouri, Montana, Nebraska, New Mexico, North Dakota, Oklahoma, South Dakota, Texas, Wisconsin, and Wyoming.Powell, Robert, Roger Conant, and Joseph T. Collins. 2016. Peterson Field Guide to Reptiles and Amphibians of Eastern and Central North America, 4th ed. Houghton Mifflin Co., Boston, Massachusetts. xiii, 494 pp. [page 391] {{ISBN|978-0-544-12997-9}}Stebbins, Robert C. and Samuel M. McGinnis. 2018. Peterson Field Guide to Western Reptiles and Amphibians, 4th ed. Houghton Mifflin Co., Boston, Massachusetts. xiii, 560 pp. [page 400] {{ISBN|9781328715500}}Uetz, Peter, Paul Freed, R. Aguilar, and J. Hošek (eds.). (2021) The Reptile Database, http://www.reptile-database.org, [https://reptile-database.reptarium.cz/species?genus=Pituophis&species=catenifer&search_param=%28%28search%3D%27Pituophis%27%29%29 Pituophis catenifer] (accessed March 5, 2022)Government of Canada: [https://www.canada.ca/en/environment-climate-change/services/species-risk-public-registry/cosewic-assessments-status-reports/bullsnake-2017.html Bullsnake (Pituophis catenifer sayi): COSEWIC assessment and status report 2017] (accessed March 13, 2022 )

File:Bull Snake Wyoming closeup.jpg]]

Adult bullsnakes average about {{convert|4|to|6|ft|m|1|abbr=on}} in length, and specimens of up to {{convert|8|ft|4|in|m|1|abbr=on}} have been recorded.{{cite book|author=Roots, Clive|title=Hibernation|publisher=Greenwood Publishing Group|year=2006|isbn=978-0-313-33544-0|page=89|url=https://books.google.com/books?id=WHQFuLZBIC0C&pg=PA89}} Possibly being the largest subspecies of gopher snake on average, mature specimens can have an average weight in the range of {{convert|1|-|1.5|kg|lb|abbr=on}}, though the heavier known specimens can attain {{convert|3.6|-|4.5|kg|lb|abbr=on}}, with larger specimens being quite bulky for a colubrid snake.{{Cite web |url=https://ojs.lib.byu.edu/ojs/index.php/wnan/article/viewFile/1128/985 |title = Western North American Naturalist |archive-url=https://archive.today/20130820040418/https://ojs.lib.byu.edu/ojs/index.php/wnan/article/viewFile/1128/985 |archive-date=20 August 2013 |url-status=dead}}Ernst, Carl; Ernst, Evelyn (2003). Snakes of the United States and Canada. Washington, District of Columbia: Smithsonian Books. {{ISBN|1588340198}}Sterner RT, Petersen BE, Shumake SA, Gaddis SE, Bourassa JB, Felix TA, ... Ames AD (2002). "Movements of a bullsnake (Pituophis catenifer) following predation of a radio-collared northern pocket gopher (Thomomys talpoides)". Western North American Naturalist 62 (2): 240-242.Kaufman GA, Gibbons JW (1975). "Weight-Length Relationships in Thirteen Species of Snakes in the Southeastern United States". Herpetologica 31 (1): 31-37. This makes bullsnakes among the largest snakes native to Canada and the United States, although they are generally not as long as indigo snakes nor as heavy or as large in diameter as rattlesnakes. They are usually yellow, with brown, white, black, or sometimes reddish blotching. The blotching pattern is large blotches on top, three sets of spots on the sides, and bands of black on the tail. Many color variations have been found, including albinos and white varieties. A scale count is required to distinguish juvenile bullsnakes from other juvenile gopher snakes.{{cite web|title=Bull Snake Details|url=http://eol.org/pages/1250345/details|website=Encyclopedia of Life}}

Bullsnakes are very powerful constrictors that eat small mammals, such as mice (including Peromyscus and Reithrodontomys spp.), moles, voles, rats (including Dipodomys spp.), pocket gophers, ground squirrels (including Spermophilus spp.), young rabbits and bats, as well as ground-nesting birds, birds' eggs,Schmidt KP, Davis DD (1941). Fieldbook of Snakes of the United States and Canada. New York: G.P. Putnam's Sons. 365 pp. (Pituophis sayi sayi, pp. 163-164 + Plate 18 + Figure 46 (map) on p. 161). smaller snakes (including Crotalus spp.), lizards (including Uta spp.) and insects.Pituophis catenifer (Gopher Snake). (n.d.). Animal Diversity Web. https://animaldiversity.org/accounts/Pituophis_catenifer/ Their climbing proficiency enables them to raid bird nests (and birdhouses) to eat the nestlings or sitting mother. One snake can eat five small birds within 15 minutes. Juvenile bullsnakes depend on small lizards, frogs, and baby mice.Conant R (1975). A Field Guide to Reptiles and Amphibians of Eastern and Central North America, Second Edition. Boston: Houghton Mifflin. xviii + 429 pp. {{ISBN|0-395-19979-4}} (hardcover), {{ISBN|0-395-19977-8}} (paperback). ("Genus Pituophis", p. 198).

The idea that bullsnakes occasionally eat rattlesnakes is sometimes given as a reason for humans not to harm bullsnakes when encountering them in the wild; however, a study of 1000 bullsnakes found only two had rattlesnake in their stomach contents, so this is a very rare occurrence.{{Cite web|last=Betty|date=2009-07-10|title=Bullsnakes vs Rattlesnakes|url=https://havesnakeswilltravel.com/bullsnakes-vs-rattlesnakes-by-bryon-shipley-rattlesnake-researcher/betty/|access-date=2021-07-06|website=Have Snakes Will Travel|language=en-US}}

File:Pituophis catenifer sayi 002.jpg

Though some bullsnakes can be docile, and with some time become accustomed to handling, most are quite defensive.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. ("Bull Snakes", pp. 96-97).

When bullsnakes detect live objects too big to be prey, they seem to perceive the object as a predator and take defensive action. Their first action is to remain quiet, not moving. Then, when they feel they are able to move away from the object, their next line of defense is to move away as quickly as possible. Bullsnakes, however, are not fast movers and often must take other defensive actions. When threatened by anything as large as a human, a bullsnake's next defensive action is to rear up and make itself look as large as possible, while at the same time hissing at the perceived threat. It typically then begins lunging and retreating at the same time to escape.{{Citation needed|date=May 2011}}

Bullsnakes can sometimes be mistaken for rattlesnakes and killed. Owing to its coloration, dorsal pattern, and semikeeled scalation, it superficially resembles the western diamondback rattler (Crotalus atrox), which is also common within the same range. The bullsnake capitalizes on this similarity by performing an impressive rattlesnake impression when threatened. First, it hisses, or forcibly exhales through a glottis or extension of the windpipe. The end of the glottis is covered by a piece of cartilage known as the epiglottis, which flaps back and forth when air is exhaled from the right lung, producing a convincing rattling sound. It also adopts a rattlesnake-like "S-curve" body posture as though about to strike. It commonly vibrates its tail rapidly in brush or leaves, and flattens its head to resemble the characteristic triangular shape of the rattlesnake. These defensive behaviors are meant to scare away threats, however, and not to sound an attack.{{Citation needed|reason=Your explanation here|date=June 2020}}

In contrast to rattlesnakes, which usually keep their tails elevated to sound the most efficient rattle, bullsnakes tend to keep their tails in contact with the ground, where they can be vibrated against leaves, for example.{{Citation needed|date=May 2011}}

Bullsnakes are ectothermic reptiles and need to regulate their body temperature via thermoregulation. They can often be observed basking in sunny areas when needing to warm up and will retreat into their burrows when needing to cool down. Research indicates that bullsnakes actually prefer burrows in open grassland areas as opposed to shaded woodland areas. This is because living in an open space makes thermoregulation easier. Rather than avoiding trees and overhanging vegetation to reach a sunny area bullsnakes can simply bask in the sun at the mouth of their burrows. Thermal gradients also play a role in bullsnake thermoregulation as different temperatures at different locations will determine where the snake will travel throughout the day to maintain its preferred body temperature. {{Cite journal |last1=Johnson |first1=Noah B. |last2=Poulin |first2=Ray G. |last3=Somers |first3=Christopher M. |date=May 2022 |title=Thermoregulation by Bullsnakes (Pituophis catenifer sayi): do burrows make life easier on the prairies? |url=https://cdnsciencepub.com/doi/full/10.1139/cjz-2021-0191?af=R#abstract |journal=Canadian Journal of Zoology |volume=100 |issue=5 |pages=303–314 |doi=10.1139/cjz-2021-0191 |hdl=1807/110545 |issn=0008-4301|hdl-access=free }}

In northern regions of their range, bullsnakes will enter a dormant state called brumation in order to conserve energy during the winter months. Bullsnakes will brumate in their burrows below the frostline typically from October to April. They will often nest in large colonies even with various species of snakes like rattlesnakes and garter snakes in order to conserve heat. Bullsnakes can also shut off blood flow to certain areas of the body to control body temperature. They will decrease blood flow to the head when they are too warm in order to expel heat from their tails, and will increase blood flow to their head in colder temperatures to conserve heat. {{Cite journal |last1=Amiel |first1=Joshua J. |last2=Chua |first2=Beverly |last3=Wassersug |first3=Richard J. |last4=Jones |first4=David R. |date=2011-05-01 |title=Temperature-dependent regulation of blood distribution in snakes |url=https://journals.biologists.com/jeb/article/214/9/1458/10674/Temperature-dependent-regulation-of-blood |journal=Journal of Experimental Biology |volume=214 |issue=9 |pages=1458–1462 |doi=10.1242/jeb.053934 |pmid=21490254 |issn=0022-0949|url-access=subscription }}

Bullsnakes breed in March or April (depending upon their location) and usually lay their eggs in April, May, or June (again, depending upon when the snakes breed). They typically lay 12 eggs in sand or other protected areas and leave the eggs to incubate unprotected. Clutches of five to 22 eggs have been observed. The eggs are elliptical, leathery, rough, sticky, and up to {{convert|70|mm|in|frac=4|abbr=on}} long.Wright AH, Wright AA (1957). Handbook of Snakes of the United States and Canada. Ithaca and London: Comstock Publishing Associates, a division of Cornell University Press. 1,105 pp. (in 2 volumes). (Pituophis catenifer sayi, pp. 604–609, Figure 175 + Map 46 on p. 589). The eggs typically hatch in August or September. Baby bull snakes are {{convert|20|–|46|cm|in|abbr=on}} at hatching. Their color is grayish until after their first shed.{{Citation needed|date=November 2013}}

{{Reflist}}

• Schlegel H (1837). Essai sur la physionomie des serpens, Volume II., Partie Descriptive {{In lang|fr}}. Amsterdam: M.H. Schonekat. 606 + xv pp. (Coluber sayi, new species, pp. 157–158.)

• [http://www.animalspot.net/bull-snake.html Animalspot.net: Bull Snake]
• [https://www.iowaherps.com/species/pituophis_catenifer_sayi IowaHerps.com: Pituophis catenifer sayi (Iowa Bullsnake)]

{{Taxonbar|from=Q4113884}}

{{Authority control}}

Category:Pituophis

Category:Snakes of North America

Category:Reptiles of Canada

Category:Reptiles of Mexico

Category:Reptiles of the United States

Category:Fauna of Central Mexico

Category:Fauna of Northern Mexico

Category:Fauna of the Great Plains

Category:Fauna of the Plains-Midwest (United States)

Category:Fauna of Western Canada

Category:Taxa named by Hermann Schlegel