When nearing the breeding season, Arrau turtles migrate to certain sites where the eggs are laid.
In some locations nesting occurs in large groups on beaches, which reduces the risk posed by predators.
Some beaches have as many as 500 nesting females.
Mating occurs in the water.
During and just before the nesting season the species frequently basks, typically in groups.
It is suspected that the additional heat accelerates the ovulation in the females.
At other times the species is generally not found on land.
When on land, it is usually very shy and retreats to the water at the slightest hint of danger.
The female lays an average of 75–123 eggs (average varies depending on region), which are placed during the night in a 60–80 cm (2.0–2.6 ft) deep nest that is dug on the beach.
The eggs are laid during the low water season and hatch as the water starts to rise.
If it rises too fast or too early, the nest is flooded and the young die within the eggs.
As long as nests are not dug up by predators, the hatching success rate is usually high, averaging at 83%.
The eggs hatch after about 50 days and the sex of the young depends on the nest temperature (females at higher temperatures, males at lower).
When hatching, the young are around 5 cm (2 in) long and dart directly for the water, but they emerge to the attentions of many predators so that only about five percent ever reach the adult feeding grounds.
When hatching, the females emit sounds which attract the young; they stay together for a period in the flooded forests.
Vocalizations appear to play an important role in the social life of this turtle and in addition to the "connect to newly hatched young" sound, four primary sounds have been documented during the nesting season: one used during migration, one before basking, one when nesting at night and finally one when in the water after nesting.

They can reach an age of 20 years or more in the wild, and captives have lived for at least 25 years.
Based on certain scientific models it has been estimated that the largest individuals perhaps are as old as 80 years.
When nearing the breeding season, Arrau turtles migrate to certain sites where the eggs are laid. In some locations nesting occurs in large groups on beaches, which reduces the risk posed by predators. Some beaches have as many as 500 nesting females. Mating occurs in the water. During and just before the nesting season the species frequently basks, typically in groups. It is suspected that the additional heat accelerates the ovulation in the females. At other times the species is generally not found on land. When on land, it is usually very shy and retreats to the water at the slightest hint of danger. The female lays an average of 75–123 eggs (average varies depending on region), which are placed during the night in a 60–80 cm (2.0–2.6 ft) deep nest that is dug on the beach. The eggs are laid during the low water season and hatch as the water starts to rise. If it rises too fast or too early, the nest is flooded and the young die within the eggs. As long as nests are not dug up by predators, the hatching success rate is usually high, averaging at 83%. The eggs hatch after about 50 days and the sex of the young depends on the nest temperature (females at higher temperatures, males at lower). When hatching, the young are around 5 cm (2 in) long and dart directly for the water, but they emerge to the attentions of many predators so that only about five percent ever reach the adult feeding grounds. When hatching, the females emit sounds which attract the young; they stay together for a period in the flooded forests. Vocalizations appear to play an important role in the social life of this turtle and in addition to the "connect to newly hatched young" sound, four primary sounds have been documented during the nesting season: one used during migration, one before basking, one when nesting at night and finally one when in the water after nesting.
They can reach an age of 20 years or more in the wild, and captives have lived for at least 25 years. Based on certain scientific models it has been estimated that the largest individuals perhaps are as old as 80 years.
Arrau turtle