Atelopus chiriquiensis – Chiriquí harlequin frog
These attractive diurnal frogs were appealing research subjects and occurred in high numbers in highlands on the border of Costa Rica and Panama. There are many scientific papers about this species, and they were primarily studied for their highly toxic tetradotoxins in their skin as well as their unique signaling and aggressive mating behavior. A study by Dr. Karen Lips in the las Tablas reserve of Costa Rica reports that they occurred in high numbers – up to 20 individuals seen in 100m of stream on a single visit, but the frogs experienced a severe chytridiomycosis-related decline over a 5-year period and were last seen in 1996.