Bullsnake
Encyclopedia
The bullsnake is a large non-venomous colubrid
snake
, widespread in the central part of the United States
, northern Mexico
, and southwestern Saskatchewan
and Alberta
Canada
. It is currently considered a subspecies of the gopher snake (Pituophis catenifer
). The epithet sayi is in honor of zoologist
Thomas Say
.
, northern Mexico
, and southwestern Saskatchewan
and Alberta
Canada
. This includes the U.S. states of Arizona
, Colorado
, Idaho
, Illinois
, Indiana
, Iowa
, Kansas
, Minnesota
, Missouri
, Montana
, Nebraska
, Nevada
, New Mexico
, North Dakota
, Oklahoma
, Oregon
, South Dakota
, Texas
, Utah
, Wisconsin
, eastern Washington
, and Wyoming
.
s nor as large in diameter as rattlesnake
s. They are usually yellow
in color, with brown
, black
or sometimes red
dish colored blotching. The blotching pattern is as follows: 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 juvenile gopher snakes.
s, birds' eggs and lizards. Juvenile bullsnakes depend on small lizards, frogs, and baby mice. Bullsnakes kill their prey via constriction.
(The idea that bullsnakes occasionally eat rattlesnake
s is sometimes touted as a reason for humans not to harm bull snakes when encountering them in the wild, although a better reason is the bullsnake's role in controlling warm-blooded vermin such as rodents.)
Though some bullsnakes can be docile, and with some time become accustomed to handling, most bullsnakes are quite defensive and known for their perceived "bad attitude".
When threatened by anything as large as a human, a bullsnake's primary defense is to rear up and make it look as large as possible. They typically then begin lunging and backtracking at the same time in order to escape.
Bullsnakes are sometimes mistaken for rattlesnakes and killed by laypersons. Due to its coloration, dorsal pattern, and semi-keeled scalation; the Bullsnake superficially resembles the Western Diamondback Rattler (Crotalus atrox
), which is also common within the same range. The bullsnake capitalizes on this similarity by performing a very impressive rattlesnake impression when threatened. First, it hisses, or forcibly exhales through a bisected glottis, which flaps back and forth producing a very convincing "rattle" sound. It will also take on a rattlesnake-like "S-curve" body posture, as if it is going to strike. The bullsnake will commonly vibrate its tail rapidly amongst the brush or leaves, and flatten its head to make it take on a more characteristic triangular-shaped head of the rattlesnake. These defensive behaviors are meant to scare away threats, however, not sound an attack.
In contrast to rattlesnakes, which usually keep their tail elevated in order to sound the most efficient rattle, bullsnakes tend to keep their tail in contact with the ground, in order to beat it against something to make a sound.
Their rattlesnake mimicry is so impressive that it is sometimes the bullsnake's very undoing when discovered by humans.
Colubrid
A colubrid is a member of the snake family Colubridae. This broad classification of snakes includes about two-thirds of all snake species on earth. The earliest species of the snake family date back to the Oligocene epoch. With 304 genera and 1,938 species, Colubridae is the largest snake family...
snake
Snake
Snakes are elongate, legless, carnivorous reptiles of the suborder Serpentes that can be distinguished from legless lizards by their lack of eyelids and external ears. Like all squamates, snakes are ectothermic, amniote vertebrates covered in overlapping scales...
, widespread in the central part of the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
, northern Mexico
Mexico
The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...
, and southwestern Saskatchewan
Saskatchewan
Saskatchewan is a prairie province in Canada, which has an area of . Saskatchewan is bordered on the west by Alberta, on the north by the Northwest Territories, on the east by Manitoba, and on the south by the U.S. states of Montana and North Dakota....
and Alberta
Alberta
Alberta is a province of Canada. It had an estimated population of 3.7 million in 2010 making it the most populous of Canada's three prairie provinces...
Canada
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...
. It is currently considered a subspecies of the gopher snake (Pituophis catenifer
Pituophis catenifer
Pituophis catenifer is a harmless colubrid species found in North America. Six subspecies are currently recognized, including the nominate subspecies described here. The specific name catenifer is Latin for 'chain bearing', referring to the dorsal color pattern.-Description:Adults specimens are...
). The epithet sayi is in honor of zoologist
Zoology
Zoology |zoölogy]]), is the branch of biology that relates to the animal kingdom, including the structure, embryology, evolution, classification, habits, and distribution of all animals, both living and extinct...
Thomas Say
Thomas Say
Thomas Say was an American naturalist, entomologist, malacologist, herpetologist and carcinologist. A taxonomist, he is often considered to be the father of descriptive entomology in the United States. He described more than 1,000 new species of beetles and over 400 species of insects of other...
.
Range
Bullsnakes can be found throughout the central United StatesUnited States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
, northern Mexico
Mexico
The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...
, and southwestern Saskatchewan
Saskatchewan
Saskatchewan is a prairie province in Canada, which has an area of . Saskatchewan is bordered on the west by Alberta, on the north by the Northwest Territories, on the east by Manitoba, and on the south by the U.S. states of Montana and North Dakota....
and Alberta
Alberta
Alberta is a province of Canada. It had an estimated population of 3.7 million in 2010 making it the most populous of Canada's three prairie provinces...
Canada
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...
. This includes the U.S. states of Arizona
Arizona
Arizona ; is a state located in the southwestern region of the United States. It is also part of the western United States and the mountain west. The capital and largest city is Phoenix...
, Colorado
Colorado
Colorado is a U.S. state that encompasses much of the Rocky Mountains as well as the northeastern portion of the Colorado Plateau and the western edge of the Great Plains...
, Idaho
Idaho
Idaho is a state in the Rocky Mountain area of the United States. The state's largest city and capital is Boise. Residents are called "Idahoans". Idaho was admitted to the Union on July 3, 1890, as the 43rd state....
, Illinois
Illinois
Illinois is the fifth-most populous state of the United States of America, and is often noted for being a microcosm of the entire country. With Chicago in the northeast, small industrial cities and great agricultural productivity in central and northern Illinois, and natural resources like coal,...
, Indiana
Indiana
Indiana is a US state, admitted to the United States as the 19th on December 11, 1816. It is located in the Midwestern United States and Great Lakes Region. With 6,483,802 residents, the state is ranked 15th in population and 16th in population density. Indiana is ranked 38th in land area and is...
, Iowa
Iowa
Iowa is a state located in the Midwestern United States, an area often referred to as the "American Heartland". It derives its name from the Ioway people, one of the many American Indian tribes that occupied the state at the time of European exploration. Iowa was a part of the French colony of New...
, Kansas
Kansas
Kansas is a US state located in the Midwestern United States. It is named after the Kansas River which flows through it, which in turn was named after the Kansa Native American tribe, which inhabited the area. The tribe's name is often said to mean "people of the wind" or "people of the south...
, Minnesota
Minnesota
Minnesota is a U.S. state located in the Midwestern United States. The twelfth largest state of the U.S., it is the twenty-first most populous, with 5.3 million residents. Minnesota was carved out of the eastern half of the Minnesota Territory and admitted to the Union as the thirty-second state...
, Missouri
Missouri
Missouri is a US state located in the Midwestern United States, bordered by Iowa, Illinois, Kentucky, Tennessee, Arkansas, Oklahoma, Kansas and Nebraska. With a 2010 population of 5,988,927, Missouri is the 18th most populous state in the nation and the fifth most populous in the Midwest. It...
, Montana
Montana
Montana is a state in the Western United States. The western third of Montana contains numerous mountain ranges. Smaller, "island ranges" are found in the central third of the state, for a total of 77 named ranges of the Rocky Mountains. This geographical fact is reflected in the state's name,...
, Nebraska
Nebraska
Nebraska is a state on the Great Plains of the Midwestern United States. The state's capital is Lincoln and its largest city is Omaha, on the Missouri River....
, Nevada
Nevada
Nevada is a state in the western, mountain west, and southwestern regions of the United States. With an area of and a population of about 2.7 million, it is the 7th-largest and 35th-most populous state. Over two-thirds of Nevada's people live in the Las Vegas metropolitan area, which contains its...
, New Mexico
New Mexico
New Mexico is a state located in the southwest and western regions of the United States. New Mexico is also usually considered one of the Mountain States. With a population density of 16 per square mile, New Mexico is the sixth-most sparsely inhabited U.S...
, North Dakota
North Dakota
North Dakota is a state located in the Midwestern region of the United States of America, along the Canadian border. The state is bordered by Canada to the north, Minnesota to the east, South Dakota to the south and Montana to the west. North Dakota is the 19th-largest state by area in the U.S....
, Oklahoma
Oklahoma
Oklahoma is a state located in the South Central region of the United States of America. With an estimated 3,751,351 residents as of the 2010 census and a land area of 68,667 square miles , Oklahoma is the 28th most populous and 20th-largest state...
, Oregon
Oregon
Oregon is a state in the Pacific Northwest region of the United States. It is located on the Pacific coast, with Washington to the north, California to the south, Nevada on the southeast and Idaho to the east. The Columbia and Snake rivers delineate much of Oregon's northern and eastern...
, South Dakota
South Dakota
South Dakota is a state located in the Midwestern region of the United States. It is named after the Lakota and Dakota Sioux American Indian tribes. Once a part of Dakota Territory, South Dakota became a state on November 2, 1889. The state has an area of and an estimated population of just over...
, Texas
Texas
Texas is the second largest U.S. state by both area and population, and the largest state by area in the contiguous United States.The name, based on the Caddo word "Tejas" meaning "friends" or "allies", was applied by the Spanish to the Caddo themselves and to the region of their settlement in...
, Utah
Utah
Utah is a state in the Western United States. It was the 45th state to join the Union, on January 4, 1896. Approximately 80% of Utah's 2,763,885 people live along the Wasatch Front, centering on Salt Lake City. This leaves vast expanses of the state nearly uninhabited, making the population the...
, Wisconsin
Wisconsin
Wisconsin is a U.S. state located in the north-central United States and is part of the Midwest. It is bordered by Minnesota to the west, Iowa to the southwest, Illinois to the south, Lake Michigan to the east, Michigan to the northeast, and Lake Superior to the north. Wisconsin's capital is...
, eastern Washington
Eastern Washington
Eastern Washington is the portion of the U.S. state of Washington east of the Cascade Range. The region contains the city of Spokane , the Tri-Cities, the Columbia River and the Grand Coulee Dam, the Hanford Nuclear Reservation and the fertile farmlands of the Yakima Valley and the...
, and Wyoming
Wyoming
Wyoming is a state in the mountain region of the Western United States. The western two thirds of the state is covered mostly with the mountain ranges and rangelands in the foothills of the Eastern Rocky Mountains, while the eastern third of the state is high elevation prairie known as the High...
.
Description
Bullsnakes average about 6 feet (1.8 m) in length, and specimens of up to 100 inches (2.5 m) have been recorded. This makes them among the largest US snakes, although generally not as long as indigo snakeIndigo snake
The eastern indigo snake is a large nonvenomous snake with an even blue-black coloration, with some specimens having a reddish-orange to tan color on the throat, cheek and chin. This smooth- scaled snake is considered to be the largest native snake species in the United States with the longest...
s nor as large in diameter as rattlesnake
Rattlesnake
Rattlesnakes are a group of venomous snakes of the genera Crotalus and Sistrurus of the subfamily Crotalinae . There are 32 known species of rattlesnake, with between 65-70 subspecies, all native to the Americas, ranging from southern Alberta and southern British Columbia in Canada to Central...
s. They are usually yellow
Yellow
Yellow is the color evoked by light that stimulates both the L and M cone cells of the retina about equally, with no significant stimulation of the S cone cells. Light with a wavelength of 570–590 nm is yellow, as is light with a suitable mixture of red and green...
in color, with brown
Brown
Brown is a color term, denoting a range of composite colors produced by a mixture of orange, red, rose, or yellow with black or gray. The term is from Old English brún, in origin for any dusky or dark shade of color....
, black
Black
Black is the color of objects that do not emit or reflect light in any part of the visible spectrum; they absorb all such frequencies of light...
or sometimes red
Red
Red is any of a number of similar colors evoked by light consisting predominantly of the longest wavelengths of light discernible by the human eye, in the wavelength range of roughly 630–740 nm. Longer wavelengths than this are called infrared , and cannot be seen by the naked eye...
dish colored blotching. The blotching pattern is as follows: 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 juvenile gopher snakes.
Diet
Bullsnakes eat small mammals, such as mice, rats, pocket gophers, ground squirrels, rabbits, as well as ground nesting birdBird
Birds are feathered, winged, bipedal, endothermic , egg-laying, vertebrate animals. Around 10,000 living species and 188 families makes them the most speciose class of tetrapod vertebrates. They inhabit ecosystems across the globe, from the Arctic to the Antarctic. Extant birds range in size from...
s, birds' eggs and lizards. Juvenile bullsnakes depend on small lizards, frogs, and baby mice. Bullsnakes kill their prey via constriction.
(The idea that bullsnakes occasionally eat rattlesnake
Rattlesnake
Rattlesnakes are a group of venomous snakes of the genera Crotalus and Sistrurus of the subfamily Crotalinae . There are 32 known species of rattlesnake, with between 65-70 subspecies, all native to the Americas, ranging from southern Alberta and southern British Columbia in Canada to Central...
s is sometimes touted as a reason for humans not to harm bull snakes when encountering them in the wild, although a better reason is the bullsnake's role in controlling warm-blooded vermin such as rodents.)
Behavior
When threatened by anything as large as a human, a bullsnake's primary defense is to rear up and make it look as large as possible. They typically then begin lunging and backtracking at the same time in order to escape.
Bullsnakes are sometimes mistaken for rattlesnakes and killed by laypersons. Due to its coloration, dorsal pattern, and semi-keeled scalation; the Bullsnake superficially resembles the Western Diamondback Rattler (Crotalus atrox
Crotalus atrox
Crotalus atrox, the "western diamondback rattlesnake", is a venomous rattlesnake species found in the United States and Mexico. It is likely responsible for the majority of snakebite fatalities in northern Mexico and the second greatest number in the USA after C. adamanteus. No subspecies are...
), which is also common within the same range. The bullsnake capitalizes on this similarity by performing a very impressive rattlesnake impression when threatened. First, it hisses, or forcibly exhales through a bisected glottis, which flaps back and forth producing a very convincing "rattle" sound. It will also take on a rattlesnake-like "S-curve" body posture, as if it is going to strike. The bullsnake will commonly vibrate its tail rapidly amongst the brush or leaves, and flatten its head to make it take on a more characteristic triangular-shaped head of the rattlesnake. These defensive behaviors are meant to scare away threats, however, not sound an attack.
In contrast to rattlesnakes, which usually keep their tail elevated in order to sound the most efficient rattle, bullsnakes tend to keep their tail in contact with the ground, in order to beat it against something to make a sound.
Their rattlesnake mimicry is so impressive that it is sometimes the bullsnake's very undoing when discovered by humans.