Chelonoidis carbonariaRed-footed Tortoise

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Geographic Range

Red-footed tortoises (Chelonoidis carbonaria) has a broad geographic range east of the Andes that extends from eastern Columbia through the Guianas, continuing south through eastern Brazil to Rio de Janeiro, and west to Bolivia, Paraguay and northern Argentina. They appear to be absent from all but the easternmost Amazon Basin. Red-footed tortoises are also native to Panama and western Columbian on mainland South America, and the island of Trinidad in the Caribbean. They have recently been introduced to other islands in the Caribbean. (Ernst, et al., 1997; Legler, 1963; Spiess, 1997)

Habitat

Chelonoidis carbonaria can be found in rainforests, dry thorny forests, temperate forests, and in savanna areas. It prefers heavily forested, humid habitats but avoids muddy areas due to low burrowing capacity of these habitats. This species is less common in forest clearings associated with palms, mangoes, and other vegetation. (Ernst, et al., 1997; Legler, 1963)

Physical Description

The carapace of red-footed tortoises ranges from dark-brown to blackish brown. Each scute contains a pale center called the areolae. Outer regions of each scute are golden-brown, and the edges tend to be dark-brown. The plastron can range from pale to a dark yellow, and the scales on the limbs and tail are enlarged and can range from yellow to dark reddish orange. Scales on the dorsal surface of the head have dark margins and are bright in color. Parietal scales are the brightest on the head, and frontal scales are typically more pale in comparison. Males are larger than females and have a more obtuse posterior anal notch. Females have an acute or rounded posterior anal notch and their xiphiplastron (the posterior-most scute) is not as heavily developed when compared to males. In males, the posterior edge of the xiphiplastron tends to form a thickened, nearly vertical free margin, whereas in females, it tends to be beveled inward and upward. Adults can reach 510 mm in carapace length. (Ernst, et al., 1997; Legler, 1963)

  • Sexual Dimorphism
  • male larger
  • Range length
    510 (high) mm
    20.08 (high) in

Development

At reproductive maturity, Chelonoidis carbonaria exhibits a central narrowing of the shell. In older individuals, the sides of the carapace expand, especially in females, and the abdominofemoral region becomes indented and slightly saddle-backed. The tail is longer and more distinct in males when compared to females. Males have a small opening between the carapace and plastron, which allows for movement of their heavier tail. Offspring sex is determined via ambient temperature during development. (Legler, 1963)

  • Development - Life Cycle
  • temperature sex determination

Reproduction

Chelonoidis carbonaria is polygynous, and males produce sounds and calls associated with distinct gular motions that are meant to attract potential mates and ward off competitors. Calls consist of a series of “clucks”, similar to those produced by chickens. Males compete for mates, and typically move their heads in a bobbing motion prior to wrestling. He who flips his competitor on his back gains access to the female and an opportunity to mate. (Campbell and Evans, 1967; Spiess, 1997)

Most red-footed tortoises become sexually mature by 200 to 250 mm in length, which typically occurs around 5 years of age. They mate throughout the year in captivity, but nesting occurs from June through September. Females may nest several times during a season, depositing 2 to 15 eggs per clutch. Incubation times range from 117 to 158 days. Hatchlings have a carapace length ranging from 39 to 45 mm and weigh 22 to 30 g. (Ernst, et al., 1997; Legler, 1963; Spiess, 1997)

  • Breeding season
    Red-footed tortoise mate throughout the year but nest from June to September.
  • Range number of offspring
    2 to 15
  • Average age at sexual or reproductive maturity (female)
    5 years
  • Average age at sexual or reproductive maturity (male)
    5 years

In order to ensure successful egg production, female Chelonoidis carbonaria store substantial energy in the form of fat and sequester minerals in their bones for the formation of the egg-shell. During egg development, they feed on a nutrient-rich diet in order to maintain mineral deposits. Chelonoidis carbonaria lay their eggs in flask shaped nests that are about 20 cm deep in the ground. Prior to oviposition, females become restless and search for a good nesting area. Once oviposited, eggs are covered and there is no parental care. Hatchlings dig their way out of the nest and are immediately independent. (Ernst, et al., 1997; Moskovits and Kiester, 1987; Spiess, 1997; Wilkinson, 2010)

  • Parental Investment
  • pre-hatching/birth
    • provisioning
      • female

Lifespan/Longevity

There is no information available regarding the average lifespan of Chelonoidis carbonaria.

Behavior

Red-footed tortoises "gaze follow" conspecifics, which consists of gazing in the same direction as conspecifics in the immediate area. They are diurnal and appear to avoid moving great distances. Outside of their reproductive behavior, little else is known of the general behavior of this species. (Wilkinson, 2010)

Home Range

There is no information available regarding the home range of red-footed tortoises.

Communication and Perception

Chelonoidis carbonaria produces a series of clucks, which sound similar to those produced by domestic chickens. Clucks are primarily produced by males during courting or mating. Juveniles may also cluck or chirp and produce these sounds on a regular basis while foraging. Prior to clucking, juveniles stop foraging and bob their head while producing the sound. Little else is known of communication and perception in this species. (Campbell and Evans, 1972)

Food Habits

Chelonoidis carbonaria feeds primarily on fruit during the wet season and flowers during the dry season. Throughout the year, they also consume dead and living foliage, soil, fungi, stems, sand, pebbles, and carrion. Males consume greater amounts of fruit compared to females. Geocehlone carbonaria occasionally ingests sand, which has been hypothesized to act as an abrasive agent enhancing digestion of plants materials. (Moskovits and Bjorndal, 1990)

  • Plant Foods
  • leaves
  • wood, bark, or stems
  • fruit
  • flowers

Predation

Other than humans, there is no information available concerning predators specific to Chelonoidis carbonaria. (Spiess, 1997)

Ecosystem Roles

As frugivores, red-footed tortoises may be important dispersers of seeds of tropical plants such as figs and bromeliads. One study found that viable seeds of both types of plants were found in the feces of several red-footed tortoises in Brazil. (Strong and Fragoso, 2006)

  • Ecosystem Impact
  • disperses seeds

Economic Importance for Humans: Positive

Red-footed tortoises are hunted for their meat throughout their geographic range. (Legler, 1963)

  • Positive Impacts
  • food

Economic Importance for Humans: Negative

There are no known adverse effects of G. carbonaria on humans. (Spiess, 1997)

Conservation Status

Chelonoidis carbonaria has not been evaluated by the International Union for Conservation of Nature (IUCN), however, many island populations are likely in serious decline as habitat loss and over hunting pose a serious threat throughout its geographic range. Chelonoidis carbonaria occurs in numerous wildlife reserves and national parks throughout its geographic range. Without current population estimates, it is difficult to predict the potential conservation and management needs for this species. The (Spiess, 1997)

Other Comments

Chelonoidis carbonaria is also referred to as Chelenoidis carbonaria and Testudo carbonaria. (IUCN, 1982)

Contributors

Khushwant Kaur (author), Indiana University-Purdue University Fort Wayne, Mark Jordan (editor), Indiana University-Purdue University Fort Wayne, John Berini (editor), Animal Diversity Web Staff.

Glossary

Neotropical

living in the southern part of the New World. In other words, Central and South America.

World Map

acoustic

uses sound to communicate

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

carrion

flesh of dead animals.

detritus

particles of organic material from dead and decomposing organisms. Detritus is the result of the activity of decomposers (organisms that decompose organic material).

diurnal
  1. active during the day, 2. lasting for one day.
ectothermic

animals which must use heat acquired from the environment and behavioral adaptations to regulate body temperature

folivore

an animal that mainly eats leaves.

food

A substance that provides both nutrients and energy to a living thing.

forest

forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.

frugivore

an animal that mainly eats fruit

herbivore

An animal that eats mainly plants or parts of plants.

heterothermic

having a body temperature that fluctuates with that of the immediate environment; having no mechanism or a poorly developed mechanism for regulating internal body temperature.

introduced

referring to animal species that have been transported to and established populations in regions outside of their natural range, usually through human action.

iteroparous

offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).

marsh

marshes are wetland areas often dominated by grasses and reeds.

motile

having the capacity to move from one place to another.

native range

the area in which the animal is naturally found, the region in which it is endemic.

omnivore

an animal that mainly eats all kinds of things, including plants and animals

oviparous

reproduction in which eggs are released by the female; development of offspring occurs outside the mother's body.

polygynous

having more than one female as a mate at one time

rainforest

rainforests, both temperate and tropical, are dominated by trees often forming a closed canopy with little light reaching the ground. Epiphytes and climbing plants are also abundant. Precipitation is typically not limiting, but may be somewhat seasonal.

sedentary

remains in the same area

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

sperm-storing

mature spermatozoa are stored by females following copulation. Male sperm storage also occurs, as sperm are retained in the male epididymes (in mammals) for a period that can, in some cases, extend over several weeks or more, but here we use the term to refer only to sperm storage by females.

swamp

a wetland area that may be permanently or intermittently covered in water, often dominated by woody vegetation.

terrestrial

Living on the ground.

tropical

the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.

tropical savanna and grassland

A terrestrial biome. Savannas are grasslands with scattered individual trees that do not form a closed canopy. Extensive savannas are found in parts of subtropical and tropical Africa and South America, and in Australia.

savanna

A grassland with scattered trees or scattered clumps of trees, a type of community intermediate between grassland and forest. See also Tropical savanna and grassland biome.

temperate grassland

A terrestrial biome found in temperate latitudes (>23.5° N or S latitude). Vegetation is made up mostly of grasses, the height and species diversity of which depend largely on the amount of moisture available. Fire and grazing are important in the long-term maintenance of grasslands.

visual

uses sight to communicate

year-round breeding

breeding takes place throughout the year

References

Campbell, H., W. Evans. 1972. Observations on the Vocal Behavior of Chelonians. Herpetologica, 28/3: 277-280.

Campbell, H., W. Evans. 1967. Sound production in two species of tortoises. Herpetologica, 23/3: 204-209.

Ernst, C., R. Altenburg, R. Barbour. 1997. "Geochelone carbonaria" (On-line). Turtles of the World. Accessed May 26, 2011 at http://nlbif.eti.uva.nl/bis/turtles.php?selected=beschrijving&menuentry=soorten&id=380.

IUCN, 1982. The IUCN Amphibia-Reptilia Red Data Book Part 1: Testudines, Crocodylia, Rhynchocaphalia. Gland, Switzerland: IUCN. Accessed June 15, 2011 at http://books.google.com/books?id=Nw8KKyu32v8C&pg=PA61&lpg=PA61&dq=Chelonoidis+carbonaria+IUCN&source=bl&ots=hBYuKrj0n8&sig=IDrMJWyAsL-dXO2VAoVJuRedu1I&hl=en&ei=hCD5TfqhCsrVgQeq46T7Cw&sa=X&oi=book_result&ct=result&resnum=1&ved=0CBoQ6AEwAA#v=onepage&q=Chelonoidis%20carbonaria&f=false.

Legler, J. 1963. Tortoises (Geochelone carbonaria) in Panama: distribution and variation. American Midland Naturalist, 70/2: 490-503.

Moskovits, D., A. Kiester. 1987. Activity levels and ranging behavior of the two Amazonian tortoises, Geochelone carbonaria and Geochelone denticulata, in north-western Brazil. Functional Ecology, 1/3: 203-214.

Moskovits, D., K. Bjorndal. 1990. Diet and food preferences of the tortoises Geochelone carbonaria and G. denticulata in northwestern Brazil. Herpetologica, 46/2: 207-218.

Spiess, P. 1997. "The Red-Footed Tortoise (Geochelone carbonaria), a South American Treasure" (On-line). Accessed March 27, 2011 at http://www.kingsnake.com/rockymountain/RMHPages/RMHredfoot.htm.

Strong, J., J. Fragoso. 2006. Seed dispersal by Geochelone carbonaria and Geochelone denticulata in northwestern Brazil. Biotropica, 38/5: 683-686.

Wilkinson, A. 2010. Gaze following in the red-footed tortoise (Geochelone carbonaria). Animal Cognition, 13/5: 765-769.