Download African Reptiles - The Maryland Zoo in Baltimore

Survey
yes no Was this document useful for you?
   Thank you for your participation!

* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project

Document related concepts

Conservation movement wikipedia , lookup

Habitat wikipedia , lookup

Habitat conservation wikipedia , lookup

Transcript
African Reptiles
Interpretive Guide
Exhibit Theme: Not all animals make good pets; in fact, our enthusiasm for keeping them can
hurt their populations in the wild.
Common Threat: Over collection for the pet trade
Both African spur-thigh and leopard tortoises are collected from the wild to be sold as
pets. They are most often collected as juveniles and are unable to reproduce before
they are caught. This slows population reproduction rates, making it difficult for
populations to replenish their numbers.
Exhibit Conservation Message:
Not all animals are good pets for everyone. Tortoises may look cute when they are
young and small, but they live for many years, require a lot of care and can grow quite
large.
Conservation Ask: Be a responsible pet owner


Don’t support the wildlife pet trade; if you decide that you want an exotic pet,
make sure you acquire it from a responsible breeder.
Make sure you can properly care for the animal; consider housing, diet,
temperature requirements and the species’ lifespan.
 If you can no longer care for a pet, do not release it into the wild.
Relevant Conservation Partners: Turtle Survival Alliance
The TSA’s mission is to transform passion for turtles into effective conservation action
through a global network of living collections and recovery programs.
Recommended Biofacts: Egyptian tortoise shell
3/31/2016
African Reptiles Interpretive Guide
The Maryland Zoo
Egyptian Tortoise Shell
Recommended Biofact
Possible Hooks: What does a tortoise use their shell for? Would you like to feel a tortoise
shell? Do you think a tortoise can walk out of its shell?
Description:


Carapace made of bone, covered in keratin scutes (modified scales)
o Shed and re-grow scutes as the tortoise or turtle grows
Avoids predation by withdrawing into the shell
“Fun Facts”:



African spur-thigh tortoises are the largest mainland tortoise species
The leopard tortoise is the fourth largest tortoise species in the world
Turtles and tortoises are connected to their shells by their spine! They cannot walk out
of their shell.
Turtle vs. Tortoise:
Tortoise
Domed carapace
Thick, sturdy legs
Lives on land
3/31/2016
Turtle
Streamlined carapace
Webbed feet
Lives in the water
Egyptian Tortoise Shell
The Maryland Zoo
Leopard Tortoise
Geochelone pardalis
Description
 Size:
o Carapace length: 30-70 cm; average 45 cm (18 in)
 Weight:
o 15-54 kg; average 18 kg (40 lbs)
 Physical Description:
o Base color of the carapace may be tan, yellow, or sometimes shades of dusty
brown. The intensity of shell patterning varies. Blotches on the shell are most
often black and are typically only present on juveniles. The head, feet, and tail
vary in color but are usually tan to brown.
o Scutes often grow in a pyramid shape; a common shell deformity among leopard
tortoises called carapacial pyramiding
 Sexual Dimorphism: Males are slightly larger than females
In the Wild
Habitat and Range
 Range:
o Widely distributed through sub-Saharan Africa
 Habitat:
o Broad ecological tolerance; ranging from dry arid plains to temperate grassland
ecosystems and have also been found in mountainous terrain
 Most often found in dry shrub habitat with low lying vegetation
Diet
 Herbivorous:
o Most tortoise species eat grasses, although leopard tortoises primarily eat forbs
(herbaceous flowering plants, excluding grasses), as well as berries and
succulents.
 Obtains water mostly from the plants that they eat, particularly
succulents
Adaptations
 Camouflage and a thick heavy shell provide protection from predators
 Turtles do not have ears, but can sense vibrations that help them navigate their
environment.
 A keen sense of smell helps them locate food
 Tear and bite food with hard, sharp, beak–like mouths
 Large anal sacs in the abdominal cavity store large amounts of water; an important
adaptation for living in an arid environment
3/31/2016
Leopard Tortoise
The Maryland Zoo
Leopard Tortoise
Geochelone pardalis
Social Structure
 Typically solitary outside of the breeding season
Lifespan/Life Cycle
 Wild: Unknown
 Captivity: 80-100 years
Ecosystem relationships
 Predators:
o Adults are rarely killed by predators; their shell affords them great protection.
o Eggs and hatchlings are eaten by a wide variety of predators, including foxes,
coyotes, and mongooses.
o Humans occasionally eat adult leopard tortoises
 Important seed dispersers
o Ingest a large number of seeds while foraging, which they then redistribute
through defecation
Reproduction
 Breeding season: May through October
 Behavior:
o Males and females become aggressive when searching for a mate.
 Males establish dominance through aggressive behavior, such as butting
and ramming into rivals
 During courtship, males follow females and repeatedly run into them.
o Nesting: After successful mating, the female searches for a suitable nest site
 She excavates the nest by kicking away loose dirt; up to 12 inches deep
 Frequent urination in the dirt may help moisten the dirt, making it easier
to dig
 Clutch Size: Ranges from 5-30 eggs
o Larger females lay more eggs
o Can lay 5-7 clutches in a single breeding season, about 3-4 weeks apart
 Incubation: approximately 460 days
o Temperature-dependent sex determination: the temperature of the eggs can
affect the sex of the developing tortoise.
 Warm environment favors females
 Cooler environment favors males
 Maturation: Hatchlings grow rapidly and there is no parental care
Activity:
 Crepuscular
o Most active early in the morning and again in the evening, when temperatures
are more moderate
3/31/2016
Leopard Tortoise
The Maryland Zoo
Leopard Tortoise
Geochelone pardalis
o Seek shelter during hottest and coldest parts of the day
Other “Fun Facts”:
 Fourth largest tortoise species in the world
 Most widely distributed tortoise species in Africa
 Tortoises occasionally eat bone fragments, soil and stones. It is thought that these items
are eaten to supplement their diet with minerals such as calcium.
Conservation Status and Threats:
 Listed as a species of “Least Concern” by the IUCN Redlist
 Listed by MZIB as stable
 Protected under CITES Appendix II
 Threats:
o Collection for the pet trade
o Hunted for food and medicine
 Leopard tortoises are a food source for indigenous people.
 Sometimes used in traditional medicine
At the Zoo

The Zoo has 3 leopard tortoises on exhibit
o Two males: Gossamer and Gremlin
 One weighing about 22 lbs and about 29 years old (in2014)
 One weighing about 11 lbs and about 13 years old (in 2014)
o One female: Fern
 24 lbs, more than 29 years old
What We Can Do



Make environmentally responsible lifestyle decisions to help conserve habitat - conserve
energy and resources, reduce litter and pollution
Support the conservation efforts of local organizations like The Maryland Zoo as well as
organizations working in the field to protect wildlife and conserve habitat. Learn more
about them, spread the word, and consider donating or getting involved.
o Turtle Survival Alliance: The TSA is comprised of many zoo professionals and
conservationists working together to transform passion for turtles into effective
conservation action through a global network of living collections and recovery
programs.
Be a responsible pet owner - not all animals make good pets for everyone, make sure
that you know how to properly care for an animal before getting it as a pet
3/31/2016
Leopard Tortoise
The Maryland Zoo
Leopard Tortoise
Geochelone pardalis

o If you can no longer care for a pet, do not release it to the wild. Not only will that
captive animal struggle to survive in a wild environment, it can negatively affect
native wildlife and possibly spread captive diseases to the wild population.
If you decide that you want an exotic pet, make sure that you acquire it from a
responsible breeder - don’t support the wildlife pet trade
References:
 Animal Diversity Web:
http://animaldiversity.ummz.umich.edu/accounts/Psammobates_pardalis/
 The Maryland Zoo website: http://www.marylandzoo.org/animalsconservation/reptiles/leopard-tortoise/
 IUCN Redlist:
http://www.iucnredlist.org/details/163449/0
 http://blogs.scientificamerican.com/tetrapod-zoology/turtles-that-eat-bone-rocks-andsoil-and-turtles-that-mine/

3/31/2016
Leopard Tortoise
The Maryland Zoo
African Spur-thigh Tortoise
Geochelone sulcata
Description
 Length
o Average about 18 in (45 cm), but can reach 24-30 in (2-2.5 ft or 60-76 cm)
 Weight
o Average about 70-100 lbs (31-45kg)
o Can reach up to 240 lbs (105 kg)
 Physical Description:
o Largest of the African mainland tortoises (only Galapagos tortoises are larger)
o Yellow to brown carapace
o Prominent growth rings on scutes
o Large overlapping scales on front legs
o Two or three large, conical spurs on hind legs; function is unknown
 Sexual dimorphism:
o Males have slightly longer, thicker tails and a more concave plastron
In the Wild
Habitat and Range
 Range: Central Africa, from Southern Sahara, Senegal, Mauritania, Mali, Nigeria, Sudan,
Chad to Ethiopia
 Habitat: Hot and arid; desert fringes, dry savannas, deciduous bushland
o Native to the Sahara Desert and the Sahel, a transitional eco-region of semi-arid
grasslands, scrub, and savannah in northern Africa
Diet


Herbivorous: grasses, weeds, cactus
Rarely, if ever, drinks water – needs are met by the water in the plants that it eats
Adaptations
 Coloration provides excellent camouflage
 Avoids predation by withdrawing completely into their shells, leaving only the front
surfaces of their scaled forelegs and the soles of their back feet showing
 Bask in the morning to raise their body temperature after lower nighttime temperatures
 Well adapted for burrowing: strong forelimbs, claws
o Keeps them cool
o Avoids dehydration
o Hatchlings may use small mammal burrows instead of digging their own
 Move slowly to conserve energy: can go for long periods of time without eating
Social Structure:
 Spur-thigh tortoises are very aggressive towards each other, even as hatchlings.
3/31/2016
African Spur-thigh Tortoise
The Maryland Zoo
African Spur-thigh Tortoise
Geochelone sulcata
o Ramming into each other and attempts to flip each other over are common male
behaviors
Lifespan
 In the wild: 50 years
 In captivity: 60-80 years
Ecosystem Relationships
 Few predators
 Young often depend on small mammal burrows until they are large enough to dig their
own.
 Herbivorous; likely to impact plant communities in their ecosystem
Reproduction
 Breeding season: Anytime from June-March, but most frequently after the rainy season
in September through November
 Behavior:
o Very aggressive toward each other, particularly during the breeding season
 Males ram other males and females
 Attempt to flip each other
 Male circles around the female and occasionally rams her with his shell
o Nesting occurs in the fall
 The female searches for a suitable nest site, for as long as two weeks
 She excavates the nest by kicking away loose dirt
 Frequent urination in the dirt may help moisten the dirt, making it
easier to dig
 Nest is about 2 ft wide and 3 to 6 inches deep and can take up to 5 hours
to dig.
 Female may dig several nests before selecting one to lay eggs in
 Clutch size: Clutch size is 15-30 eggs, sometimes more.
o Once she decides to lay, one egg is laid every 3 minutes
 Incubation: Eggs hatch after about 8 months
 Maturation:
o Hatchlings are about 2-3 inches long
o No parental care
Activity
 Crepuscular: Most active early in the morning and again in the evening, when temperatures are
more moderate
o Retreat to a burrow during the hotter and colder parts of the day; when the
temperatures are too hot or too cold for them.
3/31/2016
African Spur-thigh Tortoise
The Maryland Zoo
African Spur-thigh Tortoise
Geochelone sulcata
Other “Fun Facts”:
 In some parts of Africa, the spur-thigh tortoise is culturally significant
o Symbol of virtue, happiness, fertility, longevity
o Regarded as a mediator between man and the gods
Threats and Conservation Status
 IUCN: Vulnerable
 CITES Appendix II with a zero annual export quota for specimens removed from the wild
and traded for primarily commercial purposes. This is difficult to enforce however,
because it is hard to differentiate between wild-caught and captive bred tortoises
 Threats:
o Habitat loss and degradation, overgrazing and desertification
o Over collection for the pet trade
 Juveniles are typically collected
 Take 15 years to reach maturity, so populations may not be able to
recover from over collection
At The Zoo


1 male: Dozer
3 females: Clover, Buttercup, Sweet Pea
What We Can Do



Make environmentally responsible lifestyle decisions to help conserve habitat –
conserve energy, reduce consumption, recycle and reuse whenever possible, reduce
litter and pollution
Support the conservation efforts of local organizations like The Maryland Zoo as well as
organizations working in the field to protect wildlife and conserve habitat. Learn more
about them, spread the word, and consider donating or getting involved.
o Turtle Survival Alliance: The TSA is comprised of many zoo professionals and
conservationists working together to transform passion for turtles into effective
conservation action through a global network of living collections and recovery
programs.
Be a responsible pet owner - not all animals make good pets for everyone, make sure
that you know how to properly care for an animal before getting it as a pet
o If you can no longer care for a pet, do not release it to the wild. Not only will that
captive animal struggle to survive in a wild environment, it can negatively affect
native wildlife and possibly spread captive diseases to the wild population.
3/31/2016
African Spur-thigh Tortoise
The Maryland Zoo
African Spur-thigh Tortoise
Geochelone sulcata






Do not support the illegal pet trade. The illegal pet trade contributes to the population
decline of many tortoise species.
References and Additional Resources
http://www.arkive.org/african-spurred-tortoise/centrochelys-sulcata/
http://www.marylandzoo.org/animals-conservation/reptiles/spur-thigh-tortoise/
http://www.iucnredlist.org/details/163423/0
http://animaldiversity.ummz.umich.edu/accounts/Geochelone_sulcata/
Cogger, H.G. and Zweifel, R.G.(2003). Encyclopedia of Reptiles and Amphibians, 3rdd Edition. San
Francisco, CA: Fog City Press
3/31/2016
African Spur-thigh Tortoise
The Maryland Zoo