Galapagos Tortoise

Scientific Name: Chelonoidis

Type: Reptile

Size: Up to 2m

Diet: Herbivorous (Leafy plants, flowers, fruit)

Lifespan: 100+ years

Status: Vulnerable (Differs by island)

Facts

Tortoises continuously grow from birth to death, with older specimens weighing up to 400 kg.
Gender can be observed from tail length, since males have longer tails than females.
There are two major shell-shapes; domed and saddled. Domed are found on vegetation heavy islands while saddled is found on barren islands.
Tortoises spend 2/3 of their day resting, either sleeping or warming themselves in the sun.
Tortoises also have a symbiotic relationship with finches, who pick parasites of their skin and shell.

Evolutionary Adaptations

Structural

Thick shell for protection from predators.
Thick scales on front legs for barreling through undergrowth.
Varied saddle across islands, high saddle for reaching high fruit, low saddle for vegetated islands.
Long neck for reaching high food.
Males have divot in the bottom of shell to better mate with females (fits into bump on female's shell).
Air chambers in shell to reduce wait of heavy shell without sacrificing strength (similar to bird bones).
Air chambers in shell also help tortoise float and keep buoyancy, allowing travel across small bodies of water such as rivers.

Behavioural

Tucking head into shell to protect vitals and limbs from attack.
Migration during the year to reach food sources in the rainy or dry times.
Follows set paths through the undergrowth, based on previous paths, which reduces energy consumption (will walk through fences and barbed wire without a care).
Will sit in warm mud baths to warm up or sit in the shade to cool down (is a reptile and cold-blooded)

Physiological

Slow metabolism and large water stores helps them survive for up to a year without food, good for droughts.
Gender at birth decided by heat, and since on the equator, produces more egg-laying females.

Archipelago Variation

Santa Cruz Tortoise

As seen at the El Chato Tortoise Reserve, they have a lower saddle for pushing through undergrowth, and are now a separate species due to lifestyle and shape.

Isabela Tortoise

As seen at the Isabela Tortoise Breeding Centre, they have a slightly higher saddle for better neck reach and a slightly different head shape.