Last August, conservation biologist Melissa Costales found herself in the famous cloud forest of Ecuador. 

Her team was wondering through a private reserve in search of rainfrogs — tiny brown amphibians that look like fallen leaves. 

Suddenly, one of the researchers spotted a patch of bright green and everyone crouched down in amazement. 

“There it was,” Costales told Nat Geo, “the legendary Atelopus mindoensis!”

Commonly known as the Mindo harlequin toad, the species hadn’t been seen alive in 30 years. The toad was believed to be extinct, fallen victim to the fungal disease known as chytrid.

Scientists believe that the chytrid fungus may be responsible for the extinction of up to 90 species in the past 50 years. 

An additional 500 species have experienced a significant decline. And about one in every four of those 500 species now hold on at less than 1/10th of their former population size.

Despite that, species like the Mindo harlequin toad are a beacon of hope. 

“The fact that it has reappeared after 30 years is possibly because they have become resistant to chytrid,” says Costales.

To learn more and view Melissa Costales’ published study on her discovery, click here.