leatherback sea turtle dermochelys coriacea jordan taylor 2-10-14 “a hypocrite is the kind of...
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Leatherback Sea Turtle Dermochelys coriacea
Jordan Taylor2-10-14
“A hypocrite is the kind of politician who would cut down a redwood tree, then mount the stump and make a speech for conservation.”
Adlai E. Stevens
Bio:• Life History• Physical Characteristics• Reproduction• Diet• Habitat• Territory & Range• Behavior• Predators• Parasites• Diseases• Endangered, Why?• Status• Conservation Management• Chain Reaction
Hatchlings: Adult female nests She returns to the sea Developing hatchlings do not have sex chromosomes
Gender is determined temperature Mix of Males/Females-
“Pivotal” temperature- 83-85 degrees Fahrenheit
Females- Hotter temp
Males- Colder temp
After 45 to 70 days- Break out of eggs Caruncle: Temporary tooth located on their snout Remain in the nest Absorb yolk, attached by umbilical to their abdomen Provides energy for first few days, to the nest to offshore waters Remain until the temperature of the sand cools Less likely to be eaten by predators or overheat at night Clues to find the water including:
Slope of the beach White crests of the waves Light of the ocean horizon
Life History:
Juveniles: Size of dinner plates Return to coastal until they reach sexual maturity
(adulthood) Feed over enormous areas-
Shallow waters Sexual maturity-
15 years Leave coastal areas/migrate Thousands of miles To breeding areas to mate
Life History: Cont.
Adults: Females-
Nesting- Come ashore to lay eggs Wait for darkness before leaving water Digs nest with rear flippers 100 or more ping-pong ball sized eggs May take a few hours or more Cover and disguise nest before returning to water Never sees hatchlings once born Six weeks to two months later
Nesting season ends- Return to hunting grounds Not nesting again 2 to 3 years Continue to mature 30 year in captivity 50-70 year old in wild May live a century
Life Cycle: Cont.
Largest sea turtles 4 to 8 feet in length 500 to 2000 pounds Shell-
small bones covered by rubbery skin with seven longitudinal ridges or keels
Skin- Black with pale spotting Pink spot on the dorsal surface of the head in adults Paddle-like clawless limbs: black with white margins/pale spotting.
Jaw- Tooth-like point located on each side of the gray upper jaw lower jaw is hooked
Physical Characteristics:
Nesting- March to July 5 to 7 times 11 nests 9 to 10 days of Constructs at night in clutches with an average of 80 to 85 eggs Eggs 2 inches in diameter Incubation takes 55 to 75 days
Hatchlings: Hatch at night Return to their nesting beaches every 2 to 3-years Sexual maturity about 16 years Coloration-
Black with white flipper margins and keels
Significant Nesting Areas- Caribbean-
Puerto Rico U.S. Virgin Islands
Southeast Florida Largest Nesting Areas-
Northern South America West Africa
Reproduction:
Jellyfish Sea urchins Squid Crustaceans Tunicates Fish Blue-green algae Floating seaweed
Diet:
TunicatesSea urchins
Crustaceans
Habitat: • Beaches:– Deep water– Rough seas– Vegetation– Sloped- Safe distance from dry sand and water
Distributed worldwide in tropical and temperate waters of the Atlantic, Pacific, and Indian Oceans
Small numbers far north: British Columbia Newfoundland the British Isles
Small numbers far south: Australia Cape of Good Hope Argentina
Recent estimates for the North Atlantic: Range of 34,000 to 94,000 adult
Territory & Range:
Independent Migrate:
Great distances between nesting and feeding grounds
Located: High concentrations of jellyfish Feed near the surface Highest concentrations of prey
Behavior:
Predators: Humans- #1 predator Eggs:
Lizards Birds-
Knots Plovers Raptors
Mammals- Raccoons Dogs
Hatchlings: Cephalopods Sharks Large fish
Adult leatherbacks: Jaguars Killer whales Large sharks
Predators:
Piping Plover
Red Knot
Cephalopods
Fibropapilloma- Water pollution
Tumors Found on Body: Lungs Kidneys Liver
Causes: Oil spills Runoff- Chemicals Fertilizers Toxic waste
Destroys food sources: Aquatic plants Animals
Diseases:
Once the world’s largest population Exploitation by humans:
Eggs meat Commercial fisheries/Over harvesting Long-line fishing- Long fishing line with multiply hooks
Other factors: Loss of nesting habitat from coastal development Confusing hatchlings by beachfront lighting Native predators/non-native predators Marine pollution/debris Watercraft strikes
Endangered, Why?:
Delaware: Seen in the Chesapeake Bay Less frequently the Delaware Bay Habitat loss/ change Continues loss of open space to development
Federal: Registered June 2nd,1970 Endangered through out range
Listed endangered both state & federal governments
Status:
Increase hatchling populations: Southeastern U.S. and U.S. Caribbean-
Nest protection efforts/beach habitat protection Reduce leatherback deaths from long-line fishery Coastal counties/communities have developed lighting regulations U.S. nesting beaches continue for long-term protection
Pacific coasts of- Mexico Costa Rica Other Central American countries
Eliminating Long-Line Fishing: WWF-
Working with fisheries to switch to more turtle-friendly fishing hooks ("circle" hooks) Satellite devices:
Tracks turtle movements
Conservation Management:
Leatherback sea turtles are predators: Affect prey population densities is unknown Might have been important before their
populations were reduced by harvesting Leatherback eggs and hatchlings:
Food source for egg predator populations
Chain Reaction:
All In All…
• Populations decreasing• Support conservation groups• Stop pollution• Encourage local fisherman to be apart of
conservation • Effect our eco-systems• Encourage others• Spread the word• Be involved in local conservation projects
http://www.fws.gov/northflorida/seaturtles/turtle%20factsheets/leatherback-sea-turtle.htm
http://worldwildlife.org/species/leatherback-turtle http://www.nmfs.noaa.gov/pr/species/turtles/leatherback.htm http://conserveturtles.org/seaturtleinformation.php?page=leatherback http://www.seeturtles.org/915/leatherback-turtle.html http://www.turtles.org/leatherd.htm http://animaldiversity.ummz.umich.edu/accounts/Dermochelys_coriac
ea/#behavior
http://people.wcsu.edu/pinout/herpetology/dcoriacea/conservation.html
http://www.delawareonline.com/article/20060512/LIFE/605120326/Delaware-home-15-species-turtles
Resources: