Nine-banded Armadillo
Encyclopedia
The nine-banded armadillo (Dasypus novemcinctus), or the nine-banded, long-nosed armadillo, is a species of armadillo
found in North
, Central
, and South America
, making it the most widespread of the armadillos. Its ancestors originated in South America, and remained there until 3 million years ago, when the formation of the Isthmus of Panama
allowed them to enter North America as part of the Great American Interchange
.
The nine-banded long-nosed armadillo is a solitary, mainly nocturnal animal, found in many kinds of habitats, from mature and secondary rainforest
s to grassland
and dry scrub
. It is an insectivorous
animal, feeding chiefly on ant
s, termite
s, and other small invertebrate
s. The armadillo can jump 3–4 ft (91.4–121.9 cm) straight in the air if sufficiently frightened, making it a particular danger on roads.
s, and tropical rainforest
s. They cannot thrive in particularly cold or dry environments, as their large surface area, which is not well insulated by fat, makes them especially susceptible to heat and water loss.
The nine-banded armadillo has been rapidly expanding its range both north and east within the United States
. The armadillo crossed the Rio Grande
from Mexico
in the late 19th century, and was introduced in Florida
at about the same time by humans. By 1995, the species had become well-established in Texas
, Oklahoma
, Louisiana
, Arkansas
, Mississippi
, Alabama
, and Florida, and had been sighted as far afield as Kansas
, Missouri
, Tennessee
, Georgia
and South Carolina
. A decade later, the armadillo had become established in all of those areas and continued its migration, being sighted as far north as southern Nebraska
, southern Illinois
, and southern
Indiana
.
The primary cause of this rapid expansion is explained simply by the existence of few or no natural predators of the armadillo within the United States, little desire on the part of Americans to hunt or eat the armadillo, and the animals' high reproductive rate. The northern expansion of the armadillo is expected to continue until the species reaches as far north as Ohio
, Pennsylvania
, and New Jersey
and all points southward on the East Coast of the United States
. Further northward and westward expansion will probably be limited by the armadillo's poor tolerance of harsh winters, due to its lack of insulating fat and its inability to hibernate
.
As of 2009, newspaper reports indicated the nine-banded armadillo seems to have expanded its range northward as far as Lincoln, Nebraska
in the west, and as far north as Kentucky Dam
and Evansville, Indiana
in the east.. In late 2009, the state of North Carolina began considering the establishment of a hunting season for armadillo, following reports that the species has been moving into the southern reaches of the state (roughly between the areas of Charlotte, North Carolina
and Wilmington, North Carolina
).
Outside the United States, the nine-banded armadillo ranges southward through Central and South America into northern Argentina
and Uruguay
, where it is still expanding its range.
In 1995, armadillos were only seen in the southern tip of South Carolina; however, in two to three years they had swept across most of the state.
s. They forage for meals by thrusting their snouts into loose soil and leaf litter and frantically digging in erratic patterns, stopping occasionally to dig up grubs, beetle
s, ant
s, termite
s, and worms, which their sensitive noses can detect through 8 inches (20.3 cm) of soil. They then lap up the insects with their sticky tongues. They supplement their diets with amphibian
s, small reptile
s, fungi, tuber
s, and carrion
.
The outer shell is composed of ossified
dermal scute
s covered by nonoverlapping, keratinized epidermal
scales
, which are connected by flexible bands of skin. This armor covers the back, sides, head, tail, and outside surfaces of the legs. The underside of the body and the inner surfaces of the legs have no armored protection. Instead, they are covered by tough skin and a layer of coarse hair. The vertebrae are specially modified to attach to the carapace
.
The claws on the middle toes of the forefeet are elongated for digging, though not to the same degree as those of the much larger giant armadillo
of South America.
Their low metabolic rate and poor thermoregulation
make them best suited for semi-tropical environments.
Unlike the South American three-banded armadillos
, the nine-banded armadillo cannot roll itself into a ball. It is, however, capable of floating across rivers by inflating its intestine
s, or by sinking and running across riverbeds. The second is possible due to its ability to hold its breath for up to six minutes, an adaptation originally developed for allowing the animal to keep its snout submerged in soil for extended periods while foraging. Although nine is the typical number of bands on the nine-banded armadillo, the actual number varies by geographic range.
Armadillos possess the teeth typical of all sloth
s, and anteater
s. The teeth are all small, peg-like molars
with open roots and no enamel
. Incisor
s do form in the embryos, but quickly degenerate and are usually absent by birth.
Armadillos mark their territory with urine, feces, and excretions from scent gland
s found on the eyelids, nose, and feet. Females tend to have exclusive, clearly defined territories. Males have larger territories, but theirs often overlap, and can coincide with the ranges of several females. Territorial disputes are settled by kicking and chasing.
When they are not foraging, armadillos shuffle along fairly slowly, stopping occasionally to sniff the air for signs of danger. If alarmed, they can flee with surprising speed. If this method of escape fails, the armadillo may quickly dig a shallow trench and lodge itself inside. Predators are rarely able to dislodge the animal, and abandon their prey when they cannot breach the armadillo’s armor.
and November–January in the Southern Hemisphere
. A single egg is fertilized, but implantation is delayed for three to four months to ensure the young will not be born during an unfavorable time. Once the zygote
does implant in the uterus, a gestation period of four months occurs, during which the zygote splits into four identical embryo
s, each of which develops its own placenta
, so blood and nutrients are not mixed between them. After birth, the quadruplets remain in the burrow, living off the mother’s milk for approximately three months. They then begin to forage with the mother, eventually leaving after six months to a year.
Nine-banded armadillos reach sexual maturity at the age of one year, and reproduce every year for the rest of their 12–15 year lifespans. A single female can produce up to 56 young over the course of her life. This high reproductive rate is a major cause of the species’ rapid expansion.
s, cotton rat
s, burrowing owl
s, and rattlesnake
s, all of which can be found living in abandoned armadillo burrows.
They are typically hunted for their meat, which is said to taste like pork, but are more frequently killed as a result of their tendency to steal the eggs of poultry and game birds. This has caused certain populations of the nine-banded armadillo to become threatened, although the species as a whole is under no immediate threat.
They are also valuable for use in medical research, as they are one of the few animals susceptible to the human disease leprosy
.
In Texas, nine-banded armadillos are raised to participate in armadillo racing, a small-scale, but well-established sport in which the animals scurry down a 40-foot track.
, the species was hunted for its meat in East Texas
, where it was known as the poor man’s pork, or the "Hoover hog" by those who considered President Herbert Hoover
to be responsible for the depression. Earlier, German settlers in Texas
would often refer to the armadillo as Panzerschwein ("armored pig"). In 1995, the nine-banded armadillo was, with some resistance, made the state small mammal of Texas, where it is considered a pest and is often seen dead on the roadside
. They first forayed into Texas across the Rio Grande
from Mexico in the 19th century, eventually spreading across the southeast United States.
North American subspecies
exhibit reduced genetic variability
compared with the subspecies of South America, indicating the armadillos of North America are descended from a relatively small number of individuals that migrated from south of the Rio Grande.
Armadillo
Armadillos are New World placental mammals, known for having a leathery armor shell. Dasypodidae is the only surviving family in the order Cingulata, part of the superorder Xenarthra along with the anteaters and sloths. The word armadillo is Spanish for "little armored one"...
found in North
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...
, Central
Central America
Central America is the central geographic region of the Americas. It is the southernmost, isthmian portion of the North American continent, which connects with South America on the southeast. When considered part of the unified continental model, it is considered a subcontinent...
, and South America
South America
South America is a continent situated in the Western Hemisphere, mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere. The continent is also considered a subcontinent of the Americas. It is bordered on the west by the Pacific Ocean and on the north and east...
, making it the most widespread of the armadillos. Its ancestors originated in South America, and remained there until 3 million years ago, when the formation of the Isthmus of Panama
Isthmus of Panama
The Isthmus of Panama, also historically known as the Isthmus of Darien, is the narrow strip of land that lies between the Caribbean Sea and the Pacific Ocean, linking North and South America. It contains the country of Panama and the Panama Canal...
allowed them to enter North America as part of the Great American Interchange
Great American Interchange
The Great American Interchange was an important paleozoogeographic event in which land and freshwater fauna migrated from North America via Central America to South America and vice versa, as the volcanic Isthmus of Panama rose up from the sea floor and bridged the formerly separated continents...
.
The nine-banded long-nosed armadillo is a solitary, mainly nocturnal animal, found in many kinds of habitats, from mature and secondary rainforest
Rainforest
Rainforests are forests characterized by high rainfall, with definitions based on a minimum normal annual rainfall of 1750-2000 mm...
s to grassland
Grassland
Grasslands are areas where the vegetation is dominated by grasses and other herbaceous plants . However, sedge and rush families can also be found. Grasslands occur naturally on all continents except Antarctica...
and dry scrub
Deserts and xeric shrublands
Deserts and xeric shrublands is a biome characterized by, relating to, or requiring only a small amount of moisture.-Definition and occurrence:...
. It is an insectivorous
Insectivore
An insectivore is a type of carnivore with a diet that consists chiefly of insects and similar small creatures. An alternate term is entomophage, which also refers to the human practice of eating insects....
animal, feeding chiefly on ant
Ant
Ants are social insects of the family Formicidae and, along with the related wasps and bees, belong to the order Hymenoptera. Ants evolved from wasp-like ancestors in the mid-Cretaceous period between 110 and 130 million years ago and diversified after the rise of flowering plants. More than...
s, termite
Termite
Termites are a group of eusocial insects that, until recently, were classified at the taxonomic rank of order Isoptera , but are now accepted as the epifamily Termitoidae, of the cockroach order Blattodea...
s, and other small invertebrate
Invertebrate
An invertebrate is an animal without a backbone. The group includes 97% of all animal species – all animals except those in the chordate subphylum Vertebrata .Invertebrates form a paraphyletic group...
s. The armadillo can jump 3–4 ft (91.4–121.9 cm) straight in the air if sufficiently frightened, making it a particular danger on roads.
Habitat
The nine-banded armadillo evolved in a warm rainy environment and is still most commonly found in regions resembling its ancestral home. However, it is a very adaptable animal that can also be found in scrublands, open prairiePrairie
Prairies are considered part of the temperate grasslands, savannas, and shrublands biome by ecologists, based on similar temperate climates, moderate rainfall, and grasses, herbs, and shrubs, rather than trees, as the dominant vegetation type...
s, and tropical rainforest
Tropical rainforest
A tropical rainforest is an ecosystem type that occurs roughly within the latitudes 28 degrees north or south of the equator . This ecosystem experiences high average temperatures and a significant amount of rainfall...
s. They cannot thrive in particularly cold or dry environments, as their large surface area, which is not well insulated by fat, makes them especially susceptible to heat and water loss.
Range
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
. The armadillo crossed the Rio Grande
Rio Grande
The Rio Grande is a river that flows from southwestern Colorado in the United States to the Gulf of Mexico. Along the way it forms part of the Mexico – United States border. Its length varies as its course changes...
from 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...
in the late 19th century, and was introduced in Florida
Florida
Florida is a state in the southeastern United States, located on the nation's Atlantic and Gulf coasts. It is bordered to the west by the Gulf of Mexico, to the north by Alabama and Georgia and to the east by the Atlantic Ocean. With a population of 18,801,310 as measured by the 2010 census, it...
at about the same time by humans. By 1995, the species had become well-established in 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...
, 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...
, Louisiana
Louisiana
Louisiana is a state located in the southern region of the United States of America. Its capital is Baton Rouge and largest city is New Orleans. Louisiana is the only state in the U.S. with political subdivisions termed parishes, which are local governments equivalent to counties...
, Arkansas
Arkansas
Arkansas is a state located in the southern region of the United States. Its name is an Algonquian name of the Quapaw Indians. Arkansas shares borders with six states , and its eastern border is largely defined by the Mississippi River...
, Mississippi
Mississippi
Mississippi is a U.S. state located in the Southern United States. Jackson is the state capital and largest city. The name of the state derives from the Mississippi River, which flows along its western boundary, whose name comes from the Ojibwe word misi-ziibi...
, Alabama
Alabama
Alabama is a state located in the southeastern region of the United States. It is bordered by Tennessee to the north, Georgia to the east, Florida and the Gulf of Mexico to the south, and Mississippi to the west. Alabama ranks 30th in total land area and ranks second in the size of its inland...
, and Florida, and had been sighted as far afield as 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...
, 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...
, Tennessee
Tennessee
Tennessee is a U.S. state located in the Southeastern United States. It has a population of 6,346,105, making it the nation's 17th-largest state by population, and covers , making it the 36th-largest by total land area...
, Georgia
Georgia (U.S. state)
Georgia is a state located in the southeastern United States. It was established in 1732, the last of the original Thirteen Colonies. The state is named after King George II of Great Britain. Georgia was the fourth state to ratify the United States Constitution, on January 2, 1788...
and South Carolina
South Carolina
South Carolina is a state in the Deep South of the United States that borders Georgia to the south, North Carolina to the north, and the Atlantic Ocean to the east. Originally part of the Province of Carolina, the Province of South Carolina was one of the 13 colonies that declared independence...
. A decade later, the armadillo had become established in all of those areas and continued its migration, being sighted as far north as southern 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....
, southern 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,...
, and southern
Southern Indiana
Southern Indiana, in the United States, consists of the 33 counties located in the southernmost part of the state. The region's history and geography has led to a blend of Northern and Southern culture distinct from the remainder of Indiana. It is often considered to be part of the Upland South...
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...
.
The primary cause of this rapid expansion is explained simply by the existence of few or no natural predators of the armadillo within the United States, little desire on the part of Americans to hunt or eat the armadillo, and the animals' high reproductive rate. The northern expansion of the armadillo is expected to continue until the species reaches as far north as Ohio
Ohio
Ohio is a Midwestern state in the United States. The 34th largest state by area in the U.S.,it is the 7th‑most populous with over 11.5 million residents, containing several major American cities and seven metropolitan areas with populations of 500,000 or more.The state's capital is Columbus...
, Pennsylvania
Pennsylvania
The Commonwealth of Pennsylvania is a U.S. state that is located in the Northeastern and Mid-Atlantic regions of the United States. The state borders Delaware and Maryland to the south, West Virginia to the southwest, Ohio to the west, New York and Ontario, Canada, to the north, and New Jersey to...
, and New Jersey
New Jersey
New Jersey is a state in the Northeastern and Middle Atlantic regions of the United States. , its population was 8,791,894. It is bordered on the north and east by the state of New York, on the southeast and south by the Atlantic Ocean, on the west by Pennsylvania and on the southwest by Delaware...
and all points southward on the East Coast of the United States
East Coast of the United States
The East Coast of the United States, also known as the Eastern Seaboard, refers to the easternmost coastal states in the United States, which touch the Atlantic Ocean and stretch up to Canada. The term includes the U.S...
. Further northward and westward expansion will probably be limited by the armadillo's poor tolerance of harsh winters, due to its lack of insulating fat and its inability to hibernate
Hibernation
Hibernation is a state of inactivity and metabolic depression in animals, characterized by lower body temperature, slower breathing, and lower metabolic rate. Hibernating animals conserve food, especially during winter when food supplies are limited, tapping energy reserves, body fat, at a slow rate...
.
As of 2009, newspaper reports indicated the nine-banded armadillo seems to have expanded its range northward as far as Lincoln, Nebraska
Lincoln, Nebraska
The City of Lincoln is the capital and the second-most populous city of the US state of Nebraska. Lincoln is also the county seat of Lancaster County and the home of the University of Nebraska. Lincoln's 2010 Census population was 258,379....
in the west, and as far north as Kentucky Dam
Kentucky Dam
Kentucky Dam is a hydroelectric dam on the Tennessee River on the county line between Livingston County and Marshall County in the U.S. state of Kentucky...
and Evansville, Indiana
Evansville, Indiana
Evansville is the third-largest city in the U.S. state of Indiana and the largest city in Southern Indiana. As of the 2010 census, the city had a total population of 117,429. It is the county seat of Vanderburgh County and the regional hub for both Southwestern Indiana and the...
in the east.. In late 2009, the state of North Carolina began considering the establishment of a hunting season for armadillo, following reports that the species has been moving into the southern reaches of the state (roughly between the areas of Charlotte, North Carolina
Charlotte, North Carolina
Charlotte is the largest city in the U.S. state of North Carolina and the seat of Mecklenburg County. In 2010, Charlotte's population according to the US Census Bureau was 731,424, making it the 17th largest city in the United States based on population. The Charlotte metropolitan area had a 2009...
and Wilmington, North Carolina
Wilmington, North Carolina
Wilmington is a port city in and is the county seat of New Hanover County, North Carolina, United States. The population is 106,476 according to the 2010 Census, making it the eighth most populous city in the state of North Carolina...
).
Outside the United States, the nine-banded armadillo ranges southward through Central and South America into northern Argentina
Argentina
Argentina , officially the Argentine Republic , is the second largest country in South America by land area, after Brazil. It is constituted as a federation of 23 provinces and an autonomous city, Buenos Aires...
and Uruguay
Uruguay
Uruguay ,officially the Oriental Republic of Uruguay,sometimes the Eastern Republic of Uruguay; ) is a country in the southeastern part of South America. It is home to some 3.5 million people, of whom 1.8 million live in the capital Montevideo and its metropolitan area...
, where it is still expanding its range.
In 1995, armadillos were only seen in the southern tip of South Carolina; however, in two to three years they had swept across most of the state.
Diet
Nine-banded armadillos are generally insectivoreInsectivore
An insectivore is a type of carnivore with a diet that consists chiefly of insects and similar small creatures. An alternate term is entomophage, which also refers to the human practice of eating insects....
s. They forage for meals by thrusting their snouts into loose soil and leaf litter and frantically digging in erratic patterns, stopping occasionally to dig up grubs, beetle
Beetle
Coleoptera is an order of insects commonly called beetles. The word "coleoptera" is from the Greek , koleos, "sheath"; and , pteron, "wing", thus "sheathed wing". Coleoptera contains more species than any other order, constituting almost 25% of all known life-forms...
s, ant
Ant
Ants are social insects of the family Formicidae and, along with the related wasps and bees, belong to the order Hymenoptera. Ants evolved from wasp-like ancestors in the mid-Cretaceous period between 110 and 130 million years ago and diversified after the rise of flowering plants. More than...
s, termite
Termite
Termites are a group of eusocial insects that, until recently, were classified at the taxonomic rank of order Isoptera , but are now accepted as the epifamily Termitoidae, of the cockroach order Blattodea...
s, and worms, which their sensitive noses can detect through 8 inches (20.3 cm) of soil. They then lap up the insects with their sticky tongues. They supplement their diets with amphibian
Amphibian
Amphibians , are a class of vertebrate animals including animals such as toads, frogs, caecilians, and salamanders. They are characterized as non-amniote ectothermic tetrapods...
s, small reptile
Reptile
Reptiles are members of a class of air-breathing, ectothermic vertebrates which are characterized by laying shelled eggs , and having skin covered in scales and/or scutes. They are tetrapods, either having four limbs or being descended from four-limbed ancestors...
s, fungi, tuber
Tuber
Tubers are various types of modified plant structures that are enlarged to store nutrients. They are used by plants to survive the winter or dry months and provide energy and nutrients for regrowth during the next growing season and they are a means of asexual reproduction...
s, and carrion
Carrion
Carrion refers to the carcass of a dead animal. Carrion is an important food source for large carnivores and omnivores in most ecosystems. Examples of carrion-eaters include vultures, hawks, eagles, hyenas, Virginia Opossum, Tasmanian Devils, coyotes, Komodo dragons, and burying beetles...
.
Anatomy
Nine-banded armadillos weigh 12 –. Head and body length is 15 –, which combines with the 5 – tail for a total length of 20 –. They stand 6 – tall.The outer shell is composed of ossified
Ossification
Ossification is the process of laying down new bone material by cells called osteoblasts. It is synonymous with bone tissue formation...
dermal scute
Scute
A scute or scutum is a bony external plate or scale, as on the shell of a turtle, the skin of crocodilians, the feet of some birds or the anterior portion of the mesonotum in insects.-Properties:...
s covered by nonoverlapping, keratinized epidermal
Epidermis (zoology)
The Epidermis is an epithelium that covers the body of an eumetazoan . Eumetazoa have a cavity lined with a similar epithelium, the gastrodermis, which forms a boundary with the epidermis at the mouth.Sponges have no epithelium, and therefore no epidermis or gastrodermis...
scales
Scale (zoology)
In most biological nomenclature, a scale is a small rigid plate that grows out of an animal's skin to provide protection. In lepidopteran species, scales are plates on the surface of the insect wing, and provide coloration...
, which are connected by flexible bands of skin. This armor covers the back, sides, head, tail, and outside surfaces of the legs. The underside of the body and the inner surfaces of the legs have no armored protection. Instead, they are covered by tough skin and a layer of coarse hair. The vertebrae are specially modified to attach to the carapace
Carapace
A carapace is a dorsal section of the exoskeleton or shell in a number of animal groups, including arthropods such as crustaceans and arachnids, as well as vertebrates such as turtles and tortoises. In turtles and tortoises, the underside is called the plastron.-Crustaceans:In crustaceans, the...
.
The claws on the middle toes of the forefeet are elongated for digging, though not to the same degree as those of the much larger giant armadillo
Giant Armadillo
The giant armadillo , colloquially tatou, ocarro, tatu-canastra or tatú carreta, is the largest living species of armadillo...
of South America.
Their low metabolic rate and poor thermoregulation
Thermoregulation
Thermoregulation is the ability of an organism to keep its body temperature within certain boundaries, even when the surrounding temperature is very different...
make them best suited for semi-tropical environments.
Unlike the South American three-banded armadillos
Tolypeutes
The genus Tolypeutes contains the two species of three-banded armadillos. They are restricted to South America, mostly Brazil.- Species :There are two recognized species:* Tolypeutes matacus – Southern Three-banded Armadillo...
, the nine-banded armadillo cannot roll itself into a ball. It is, however, capable of floating across rivers by inflating its intestine
Intestine
In human anatomy, the intestine is the segment of the alimentary canal extending from the pyloric sphincter of the stomach to the anus and, in humans and other mammals, consists of two segments, the small intestine and the large intestine...
s, or by sinking and running across riverbeds. The second is possible due to its ability to hold its breath for up to six minutes, an adaptation originally developed for allowing the animal to keep its snout submerged in soil for extended periods while foraging. Although nine is the typical number of bands on the nine-banded armadillo, the actual number varies by geographic range.
Armadillos possess the teeth typical of all sloth
Sloth
Sloths are the six species of medium-sized mammals belonging to the families Megalonychidae and Bradypodidae , part of the order Pilosa and therefore related to armadillos and anteaters, which sport a similar set of specialized claws.They are arboreal residents of the jungles of Central and South...
s, and anteater
Anteater
Anteaters, also known as antbear, are the four mammal species of the suborder Vermilingua commonly known for eating ants and termites. Together with the sloths, they compose the order Pilosa...
s. The teeth are all small, peg-like molars
Molar (tooth)
Molars are the rearmost and most complicated kind of tooth in most mammals. In many mammals they grind food; hence the Latin name mola, "millstone"....
with open roots and no enamel
Tooth enamel
Tooth enamel, along with dentin, cementum, and dental pulp is one of the four major tissues that make up the tooth in vertebrates. It is the hardest and most highly mineralized substance in the human body. Tooth enamel is also found in the dermal denticles of sharks...
. Incisor
Incisor
Incisors are the first kind of tooth in heterodont mammals. They are located in the premaxilla above and mandible below.-Function:...
s do form in the embryos, but quickly degenerate and are usually absent by birth.
Behavior
Nine-banded armadillos are solitary, largely nocturnal animals that come out to forage around dusk. They are extensive burrowers, with a single animal sometimes maintaining up to 12 burrows on its range. These burrows are roughly 8 inches (20.3 cm) wide, 7 feet (2.1 m) deep, and 25 feet (7.6 m) long.Armadillos mark their territory with urine, feces, and excretions from scent gland
Scent gland
Scent glands are found in the genital area of most mammals and in various other parts of the body, such as the underarms of humans and the preorbital glands of deer and muskox. They produce a semi-viscous fluid which contains pheromones. These odor-messengers indicate information such as status,...
s found on the eyelids, nose, and feet. Females tend to have exclusive, clearly defined territories. Males have larger territories, but theirs often overlap, and can coincide with the ranges of several females. Territorial disputes are settled by kicking and chasing.
When they are not foraging, armadillos shuffle along fairly slowly, stopping occasionally to sniff the air for signs of danger. If alarmed, they can flee with surprising speed. If this method of escape fails, the armadillo may quickly dig a shallow trench and lodge itself inside. Predators are rarely able to dislodge the animal, and abandon their prey when they cannot breach the armadillo’s armor.
Reproduction
Mating takes place during a two to three-month-long mating season, which occurs from July–August in the Northern HemisphereNorthern Hemisphere
The Northern Hemisphere is the half of a planet that is north of its equator—the word hemisphere literally means “half sphere”. It is also that half of the celestial sphere north of the celestial equator...
and November–January in the Southern Hemisphere
Southern Hemisphere
The Southern Hemisphere is the part of Earth that lies south of the equator. The word hemisphere literally means 'half ball' or "half sphere"...
. A single egg is fertilized, but implantation is delayed for three to four months to ensure the young will not be born during an unfavorable time. Once the zygote
Zygote
A zygote , or zygocyte, is the initial cell formed when two gamete cells are joined by means of sexual reproduction. In multicellular organisms, it is the earliest developmental stage of the embryo...
does implant in the uterus, a gestation period of four months occurs, during which the zygote splits into four identical embryo
Embryo
An embryo is a multicellular diploid eukaryote in its earliest stage of development, from the time of first cell division until birth, hatching, or germination...
s, each of which develops its own placenta
Placenta
The placenta is an organ that connects the developing fetus to the uterine wall to allow nutrient uptake, waste elimination, and gas exchange via the mother's blood supply. "True" placentas are a defining characteristic of eutherian or "placental" mammals, but are also found in some snakes and...
, so blood and nutrients are not mixed between them. After birth, the quadruplets remain in the burrow, living off the mother’s milk for approximately three months. They then begin to forage with the mother, eventually leaving after six months to a year.
Nine-banded armadillos reach sexual maturity at the age of one year, and reproduce every year for the rest of their 12–15 year lifespans. A single female can produce up to 56 young over the course of her life. This high reproductive rate is a major cause of the species’ rapid expansion.
Effect on the environment
The foraging of nine-banded armadillo can cause mild damage to the root systems of certain plants, but they make up for their disruptive habits by providing homes for skunkSkunk
Skunks are mammals best known for their ability to secrete a liquid with a strong, foul odor. General appearance varies from species to species, from black-and-white to brown or cream colored. Skunks belong to the family Mephitidae and to the order Carnivora...
s, cotton rat
Cotton rat
A cotton rat is any member of the rodent genus Sigmodon. They are called cotton rats because they build their nests out of cotton, and can damage cotton crops. Cotton rats have small ears and dark coats, and are found in North and South America....
s, burrowing owl
Burrowing Owl
The Burrowing Owl is a tiny but long-legged owl found throughout open landscapes of North and South America. Burrowing Owls can be found in grasslands, rangelands, agricultural areas, deserts, or any other open dry area with low vegetation. They nest and roost in burrows, such as those excavated...
s, and 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, all of which can be found living in abandoned armadillo burrows.
They are typically hunted for their meat, which is said to taste like pork, but are more frequently killed as a result of their tendency to steal the eggs of poultry and game birds. This has caused certain populations of the nine-banded armadillo to become threatened, although the species as a whole is under no immediate threat.
They are also valuable for use in medical research, as they are one of the few animals susceptible to the human disease leprosy
Leprosy
Leprosy or Hansen's disease is a chronic disease caused by the bacteria Mycobacterium leprae and Mycobacterium lepromatosis. Named after physician Gerhard Armauer Hansen, leprosy is primarily a granulomatous disease of the peripheral nerves and mucosa of the upper respiratory tract; skin lesions...
.
In Texas, nine-banded armadillos are raised to participate in armadillo racing, a small-scale, but well-established sport in which the animals scurry down a 40-foot track.
Hoover hog
During the Great DepressionGreat Depression
The Great Depression was a severe worldwide economic depression in the decade preceding World War II. The timing of the Great Depression varied across nations, but in most countries it started in about 1929 and lasted until the late 1930s or early 1940s...
, the species was hunted for its meat in East Texas
East Texas
East Texas is a distinct geographic and ecological area in the U.S. state of Texas.According to the Handbook of Texas, the East Texas area "may be separated from the rest of Texas roughly by a line extending from the Red River in north central Lamar County southwestward to east central Limestone...
, where it was known as the poor man’s pork, or the "Hoover hog" by those who considered President Herbert Hoover
Herbert Hoover
Herbert Clark Hoover was the 31st President of the United States . Hoover was originally a professional mining engineer and author. As the United States Secretary of Commerce in the 1920s under Presidents Warren Harding and Calvin Coolidge, he promoted partnerships between government and business...
to be responsible for the depression. Earlier, German settlers in 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...
would often refer to the armadillo as Panzerschwein ("armored pig"). In 1995, the nine-banded armadillo was, with some resistance, made the state small mammal of Texas, where it is considered a pest and is often seen dead on the roadside
Roadkill
Roadkill is an animal or animals that have been struck and killed by motor vehicles. In the United States of America, removal and disposal of animals struck by motor vehicles is usually the responsibility of the state's state trooper association or department of transportation.-History:During the...
. They first forayed into Texas across the Rio Grande
Rio Grande
The Rio Grande is a river that flows from southwestern Colorado in the United States to the Gulf of Mexico. Along the way it forms part of the Mexico – United States border. Its length varies as its course changes...
from Mexico in the 19th century, eventually spreading across the southeast United States.
Subspecies
- Dasypus novemcinctus aequatorialis Lönnberg, 1913
- Dasypus novemcinctus fenestratus Peters, 1864
- Dasypus novemcinctus hoplites G.M. Allen, 1911
- Dasypus novemcinctus mexianae Hagmann, 1908
- Dasypus novemcinctus mexicanus Peters, 1864
- Dasypus novemcinctus novemcinctus Linnaeus, 1758
North American subspecies
Subspecies
Subspecies in biological classification, is either a taxonomic rank subordinate to species, ora taxonomic unit in that rank . A subspecies cannot be recognized in isolation: a species will either be recognized as having no subspecies at all or two or more, never just one...
exhibit reduced genetic variability
Genetic variability
Genetic variability is a measure of the tendency of individual genotypes in a population to vary from one another. Variability is different from genetic diversity, which is the amount of variation seen in a particular population. The variability of a trait describes how much that trait tends to...
compared with the subspecies of South America, indicating the armadillos of North America are descended from a relatively small number of individuals that migrated from south of the Rio Grande.