An estimated 210,000 baby turtles recently entered the world during a mass hatching event at Brazil's Abufari Biological Reserve, according to the Wildlife Conservation Society and the Chico Mendes Institute for Biodiversity Conservation.

Impressive as the baby turtle brigade was, the species is still threatened and endangered. All of the newborns are giant South American river turtles, also known as Arrau turtles.

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The hatching event happens every year during the dry season in Brazil — so conservationists planned in advance. They managed to mark and release approximately 15,000 of the baby turtles.

"The marked turtles will hopefully provide important data that will help inform conservation plans to safeguard this species from exploitation," Camila Ferrara, Aquatic Turtle Specialist for the WCS Brazil Program, said in a press release.

Before the turtles hatched, Ferrara and her team surveyed river sandbanks of the Purus River basin in western Brazil. This is where the turtles are known to nest.

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The researchers constructed a fence around all of the turtle nests that they were able to identify. They then collected the hatchlings as they emerged from their eggs.

Each collected baby turtle was marked so that they can be easily identified in future surveys. Data from such recaptured turtles helps conservationists to calculate dispersal patterns and survival rates.

Unfortunately, only a small number of the turtles reach adulthood.

Baby turtles turn out to be tasty and easy snacks for many predators. In fact, the evolutionary reason for the mass hatching is to overwhelm these natural predators with sheer volume. Some baby turtles are invariably snatched and eaten, but while that’s happening, siblings of the victims can continue to make their way down to the river.

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Other turtles, such as the Olive Ridley and Kemp's Ridley sea turtles, hatch in a similar "en masse" way for the same reasons.

Here's footage of Olive Ridley sea turtles nesting along the Bay of Bengal:

The giant South American river turtle, which grows to nearly three feet in length, is only found in the Amazon River basin. Conservationists aren't the only people interested in the turtles. Other people are hunting them and consuming their eggs, contributing all the more to the turtle's population decline in recent years.

"Turtles are among the most endangered species of vertebrates in the region and worldwide," said Julie Kunen, executive director of WCS's Latin America and the Caribbean Program. "Monitoring programs for these and other turtles and tortoises will provide a foundation for sound management plans in the years to come."

Image: C. Ferrara/Wildlife Conservation Society