Long lived

1
Long -lived Thermal constraints Surface
areavolume Small - bask Left-right shunt!
Large Size (8 long leatherback!) Thermal
inertia
37 degree BT in 29 deg water Counter-current
exchange of heat in flippers
2
Most aquatic and sea turtles carnivorous
(jellyfish, sponges, molluscs) Terrestrial
tortoises often herbivorous
Green Sea turtle herbivorous - sea grass
3
Mating - Males have penis - internal
fertilization Tortoises call to attract mates,
male-male fights All turtles Oviparous!
4
All turtles lay eggs in soil
10- 100 or more eggs/clutch several
clutches/season
5
Female sea turtles come ashore at night to lay
eggs - Why?
6
28-130 day incubation Group needed to dig out and
to survive race
Race for the sea Often at night Orient by 1)
light, 2) wave motion 3) magnetic Exercise
imprinting
7
TDS (Temperature Dependent Sex Determination) Fig
10-9
Male Loggerhead sea turtles at different
temperatures
8
Young turtles drift with plankton, probably join
currents in Atlantic Conservation challenges
Long Life, low repro, slow devpt Loss of breeding
sites, harvest, development Captive
breeding? Helping young to water to avoid
predators?
9
Loggerhead trans-Pacific migration
See Figure 10-11 for an astonishing
movement from Brazil across the Atlantic to
Ascension Island How do they do
it? Olfaction? Magnetic orientation?