sound, or simply jump to another location on the tree. The aggressive interaction is over when one male jumps to another (lower) leaf or flattens his body against the leaf signifying submissiveness. [7] Calling Though most vocal during the wet season, it has been reported that these frogs call throughout the year. [8] The call is used to attract a female to his territory and consists of short “chee-chee-chee”, with intermittent chirp sequences. The rate of this call ranges from 1 to 43 calls per hour, with a duration of 1.5–3 seconds. [5] The call is most intense whilst engaged in amplexus as well as after egg deposition. [7] When a male is in close proximity to another male, they call in a short series of rapid beeps. [7] Higher mating success has been seen to be correlated to longer length of calling. [10] History In the past thirty years there has been a major decline (about 40%) in amphibian populations in South America, with the emerald tree frog among them. This sudden population drop was strange and perplexing because there was very little disturbance in the area. After some research in the affected areas, there was speculation that the decline was a result of the fungus Batrachochytrium dendrobatidis, which causes chytridiomycosis in amphibians. Espadarana prosoblepon populations have remained relatively stable after the major population decline, keeping them on the IUCN species of least concern list. [6][4] Threats The emerald glass frog substantially declined in Monteverde, Costa Rica since the 1980s, though it has shown stability in other near areas. [5] There may be multiple causes for the decline including habitat destruction, negative agriculture, chemical implementation and disease. [4][5] Centrolene prosoblepon is threatened by Chytrid fungus (Batrachochytrium dendrobatidis) which causes chytridiomycosis that disrupts its skin and respiratory system. [6][7] Some frogs tend to be less threatened by Batrachochytrium dendrobatidis due to the variation in their physiology. [7] The emerald glass frog was able to persist during its decline which indicates high resistance to Batrachochytrium dendrobatidis. [7] Another threat is a chytrid collapse, which is when the majority of the population rapidly declines while a few persist. [8] There is very little information regarding predation but crabs and other small predators such as spiders have been reported to feed on Centrolene prosoblepon. [7] Generally, threats to the emerald glass frogs are related to its habitat such as deforestation, human intrusion and