Puerto Rican Coqui Frog (Eleutherodactylus coqui) guarding eggs

Puerto Rican Coquis are famous for their serenade of island residents every evening. This frog is truly part of the Puerto Rican island culture. The frogs guard developing egg masses (depicted here) and will wait with the eggs until small frogs hatch from the eggs. The larval stage passes while the developing amphibian is in the egg. This is known as direct development. There are a host of species of Coqui Frogs on Puerto Rico, some have declined sharply. Much science has gone into understanding these frogs. AmphibiaWeb had a great explanation of the science behind one of the recent studies: Narins and Smith (1983) noted that body size and call characteristics in males of Puerto Rican frogs are different when populations from differing elevations are compared. Small frogs have a short and high-pitched call when found living in low elevation forests. But in montane forests at elevation, the calls are longer, low in pitch, and the frogs have larger bodies. Fast-forward 23 years to 2006: Narins and Meenderink (2014) re-studied the same sites; at a given altitude, today's frogs are smaller with shorter and higher-pitched calls. Based on temperature data, they suggest that these changes in calls result from a warming climate that has displaced populations to higher, cooler regions. If these climatic changes continue, male calls may change to the point where females no longer recognize and respond to the mating calls, which likely would be detrimental to mating success and its survival. Caribbean islands are hotspots for amphibian endemism and we need to do everything we can to keep these biological communities around.