Brazilian Giant Tortoise - AbsoluteAstronomy.com

The Brazilian giant tortoise, forest tortoise, South American tortoise, South American yellow-footed tortoise, or yellow-footed tortoise (Chelonoidis denticulata, formerly Geochelone denticulata) is a species of tortoise in the family Testudinidae. It is found in Bolivia

Bolivia

Bolivia officially known as Plurinational State of Bolivia , is a landlocked country in central South America. It is the poorest country in South America...

, Brazil

Brazil

Brazil , officially the Federative Republic of Brazil , is the largest country in South America. It is the world's fifth largest country, both by geographical area and by population with over 192 million people...

, Colombia

Colombia

Colombia, officially the Republic of Colombia , is a unitary constitutional republic comprising thirty-two departments. The country is located in northwestern South America, bordered to the east by Venezuela and Brazil; to the south by Ecuador and Peru; to the north by the Caribbean Sea; to the...

, Ecuador

Ecuador

Ecuador , officially the Republic of Ecuador is a representative democratic republic in South America, bordered by Colombia on the north, Peru on the east and south, and by the Pacific Ocean to the west. It is one of only two countries in South America, along with Chile, that do not have a border...

, French Guiana

French Guiana

French Guiana is an overseas region of France, consisting of a single overseas department located on the northern Atlantic coast of South America. It has borders with two nations, Brazil to the east and south, and Suriname to the west...

, Guyana

Guyana

Guyana , officially the Co-operative Republic of Guyana, previously the colony of British Guiana, is a sovereign state on the northern coast of South America that is culturally part of the Anglophone Caribbean. Guyana was a former colony of the Dutch and of the British...

, Peru

Peru

Peru , officially the Republic of Peru , is a country in western South America. It is bordered on the north by Ecuador and Colombia, on the east by Brazil, on the southeast by Bolivia, on the south by Chile, and on the west by the Pacific Ocean....

, Suriname

Suriname

Suriname , officially the Republic of Suriname , is a country in northern South America. It borders French Guiana to the east, Guyana to the west, Brazil to the south, and on the north by the Atlantic Ocean. Suriname was a former colony of the British and of the Dutch, and was previously known as...

, Trinidad and Tobago

Trinidad and Tobago

Trinidad and Tobago officially the Republic of Trinidad and Tobago is an archipelagic state in the southern Caribbean, lying just off the coast of northeastern Venezuela and south of Grenada in the Lesser Antilles...

, and Venezuela

Venezuela

Venezuela , officially called the Bolivarian Republic of Venezuela , is a tropical country on the northern coast of South America. It borders Colombia to the west, Guyana to the east, and Brazil to the south...

Physical characteristics and appearance

There are several yellow head scales and a horizontal bar behind its eye. 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...

(shell top) is black with a small, distinct yellow area around the areola

Areola

This article is about the breast tissue. For the entomology term, see the glossary of Lepidopteran terms. For an artistic cloud motif, see aureola. For the cactus feature, see Areole....

on each scute (shell scale). Adult males reach a length of up to 13.5 inches (30.4 cm) in length, while the maximum size of females is 11.25 inches (28.9 cm) in length. Mature specimens have distinctive incurving of sides, giving them a well-defined "waist". The plastron (shell bottom) is a relatively bland yellow-brown; there may be some reddish tint and vague dark marks along areas of more recent growth. The plastron is extremely concave in adult males. Consequently, the male is much lighter than the female. The female has a very flat plastron and short, stubby tail. There is quite a bit of variation in coloring, with the legs and head often having patches of orange, yellow or red. The skin is black with bright yellow marks on the head and lower jaw

Mandible

The mandible pronunciation or inferior maxillary bone forms the lower jaw and holds the lower teeth in place...

. Many of the scales on the limbs and tail are bright scarlet. Specimens from west of the Andes

Andes

The Andes is the world's longest continental mountain range. It is a continual range of highlands along the western coast of South America. This range is about long, about to wide , and of an average height of about .Along its length, the Andes is split into several ranges, which are separated...

have a grayish or brownish carapace. Light limb scales are yellowish or slightly orange, but not scarlet. The plastron ranges from predominantly yellow to black. Note: There is considerable variation in color over the range of the red-footed tortoise

Red-footed tortoise

The red-footed tortoise is a tortoise native to South America. It has also been introduced to many islands in the Caribbean. It draws its name from the red or orange scales visible on its limbs, as well as its head and tail...

, so no one description will accurately describe every specimen.

This species is sexually dimorphic and it is easy to distinguish male and female. The male has an extreme plastral concavity and is subsequently much lighter. There is a pinching off at the midsection of the carapace. The female is much heavier, with a flat plastron and more symmetrical, curved carapace. The female also has a shorter tail compared to the male. The male is quite vocal at mating time with a low moan produced.

The yellow-footed tortoise is much larger with constant yellow markings compared to the red-footed tortoise (Chelonoidis carbonaria).

Natural habitat

There is some disagreement as to which habitat

Habitat

* Habitat , a place where a species lives and grows*Human habitat, a place where humans live, work or play** Space habitat, a space station intended as a permanent settlement...

is the preferred type for yellow-footed tortoises. Some feel that yellow-foots prefer grasslands and dry forest

Tropical and subtropical dry broadleaf forests

The tropical and subtropical dry broadleaf forest biome, also known as tropical dry forest, is located at tropical and subtropical latitudes. Though these forests occur in climates that are warm year-round, and may receive several hundred centimeters of rain per year, they have long dry seasons...

areas, and that rain-forest habitat is most likely marginal. Others suggest that humid forest is the preferred habitat. Regardless, they are found in drier forest areas, grasslands, and the savanna, or rainforest belts adjoining more open habitats. The red-footed tortoise

Red-footed tortoise

shares some of its range with the yellow-footed tortoise. In ranges that are shared in Surinam, the red-footed tortoise has moved out of the forests into grasslands (that are a result of slash and burn agriculture

Slash and burn

Slash-and-burn is an agricultural technique which involves cutting and burning of forests or woodlands to create fields. It is subsistence agriculture that typically uses little technology or other tools. It is typically part of shifting cultivation agriculture, and of transhumance livestock...

) while the yellow-footed tortoise has remained in the forest.

Behavior

These turtles make a sound like a baby cooing with a raspy voice. Tortoises also identify each other using body language. The male tortoise makes head movements toward other males, but the females do not make these head movements. Male tortoises also swing their heads back and forth in a continuous rhythm as a mating ritual

Courtship

Courtship is the period in a couple's relationship which precedes their engagement and marriage, or establishment of an agreed relationship of a more enduring kind. In courtship, a couple get to know each other and decide if there will be an engagement or other such agreement...

. Mating occurs all year round for the Yellow Footed Tortoise. There is no parental care of the young and the baby tortoises will fend for themselves, starting by eating calcium

Calcium

Calcium is the chemical element with the symbol Ca and atomic number 20. It has an atomic mass of 40.078 amu. Calcium is a soft gray alkaline earth metal, and is the fifth-most-abundant element by mass in the Earth's crust...

rich vegetables.

Diet

This South American tortoise eats many kinds of foliage. They are too slow to capture any fast animals. In the wild, their diet consist of grass

Grass

Grasses, or more technically graminoids, are monocotyledonous, usually herbaceous plants with narrow leaves growing from the base. They include the "true grasses", of the Poaceae family, as well as the sedges and the rushes . The true grasses include cereals, bamboo and the grasses of lawns ...

es, fallen fruit, 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...

, plants, bone

Bone

Bones are rigid organs that constitute part of the endoskeleton of vertebrates. They support, and protect the various organs of the body, produce red and white blood cells and store minerals. Bone tissue is a type of dense connective tissue...

s, mushrooms, excrement, and slow moving animals such as snail

Snail

Snail is a common name applied to most of the members of the molluscan class Gastropoda that have coiled shells in the adult stage. When the word is used in its most general sense, it includes sea snails, land snails and freshwater snails. The word snail without any qualifier is however more often...

s, worms, and others they are able to capture. In captivity, they are fed oranges, apples, melons, endive, collard greens

Collard greens

Collard greens are various loose-leafed cultivars of Brassica oleracea , the same species as cabbage and broccoli. The plant is grown for its large, dark-colored, edible leaves and as a garden ornamental, mainly in Brazil, Portugal, the southern United States, many parts of Africa, Montenegro,...

, dandelions, plantain, ribwort, clover, shredded carrots, insects, worms, cuttlebone, tortoise vitamins, edible flowers, and alfalfa pellets. Each yellow-footed tortoise in the wild reaches the age of maturity at about 8–10 years. The fecundity of a female generally depends on the size, the bigger they are, the more eggs they can produce. On average, a female will create approximately 6–16 eggs per year, although some female individuals may not reproduce each year. The eggs have brittle shells and are elongated to spherical, approximately 3–6 cm in diameter. The egg size will increase with the body size of the turtle. The young are self-sufficient from birth. The yellow-footed tortoise can live for approximately 50–60 years.

Reproduction and growth

Breeding is synchronized with the onset of the rainy season, (from July to September) where a general increase in activity is noted. Males identify each other eliciting a characteristic head movement, a series of jerks away from and back to mid-position. Another male will make the same head movements. If he gets no head movement in response, it is the first indication that the other tortoise is a female. Scientific experimentation and observation has also indicated that the head coloration has to be correct. He will then sniff the cloacal region of the other tortoise. Copulation usually follows, though sometimes there is a period of biting at the legs. During courtship and copulation the male makes clucking sounds that sound very much like a chicken. There is a set pattern in pitches of the clucking sounds. Rival males will battle, attempting to overturn each other, however neither the males nor females will defend a territory. They are considered nomadic in their movements. It is interesting to note than in almost every tortoise species where male combat occurs, the males are always larger than the females. This is in comparison to aquatic species, where the males are usually smaller than the females and do not engage in male to male combat. It is thought that species with male combat evolved larger males because larger males have a better chance of winning a bout and mating with a female, thus passing on their larger size to their offspring. Species with smaller males evolved because smaller males are more mobile and can mate with a large number of females, thus passing on their genes.

Conservation status

Chelonoidis denticulata is an endangered species. The major populations are located in 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...