Marine reptiles
Loggerhead sea turtle
Caretta caretta
Epipelagic zone
With a massive head and jaws strong enough to crush a whole conch shell, this ocean globetrotter returns, decades later, to the exact beach where it hatched — guided by a built-in magnetic compass.
🗺️ Geographic range
Found in temperate and subtropical waters of the Atlantic, Pacific, and Indian Oceans, and the Mediterranean Sea (where it is the most common sea turtle); major nesting sites include Florida, Oman, Greece, and Australia.
📊 Population
A mixed global picture: some nesting populations (southeastern US, Mediterranean) are stabilizing or increasing thanks to beach protection measures, while others, notably in the Pacific, remain severely depleted. Main threats are fisheries bycatch, coastal development destroying nesting beaches, and warming sand that skews hatchling sex ratios.
Habitat
- Mediterranean Sea · Epipelagic zone · Permanent
🥚 Reproduction
Females return to nest on their natal beach every 2–3 years, laying several clutches of about 100 eggs each, with no parental care afterward.
Behaviour
- Diet
- A durophagous diet — crabs, whelks, hard-shelled conchs — supplemented by jellyfish, fish eggs, and squid during open-ocean migrations.
- Hunting
- Uses powerful jaws to crush hard-shelled prey, sometimes diving below the thermocline to feed on it.
- Communication
- Largely non-vocal; low-frequency vocalizations have nonetheless been recorded in nesting females.
- Social life
- Largely solitary outside mating and nesting periods.
Physiology
- Anatomy
- A disproportionately large head and jaws relative to body size — the source of its 'loggerhead' name.
- Respiration
- Breathes air via lungs and can hold its breath for over 30 minutes at rest.
- Vision
- Good underwater vision, but poorly adapted to artificial light, which dangerously disorients hatchlings on lit beaches.
- Adaptations
- Has salt glands behind the eyes that excrete excess salt as 'tears,' and a magnetic sense enabling navigation across thousands of kilometers.
🔗 Web of marine life
Predators
Partners
⚡ Its extraordinary abilities
- Senses Earth's magnetic field to find its way back to its natal beach after thousands of kilometers of migration
- A jaw powerful enough to crush shellfish no other sea turtle species can access
🏆 Records
Among the longest documented transoceanic migrations of any sea turtle
Documented transoceanic migrations of several thousand kilometers, e.g. juveniles crossing the entire Pacific from Japan to Baja California.
Source: NOAA Fisheries
If you cross paths with this animal…
Risk: Very low; bites are exceptional, usually defensive or due to mistaking a swimmer for a jellyfish.
Behaviour: Rather shy and avoids humans, but may bite if cornered or handled.
Advice: Observe from a distance, never touch, chase, or block the path to the sea, especially for nesting females and hatchlings.
💡 Did you know?
- Hatchlings use Earth's magnetic field as a built-in GPS from the moment they crawl to the sea.
- Its name comes from its oversized head and jaws, strong enough to crack a whole whelk or horseshoe crab shell.
