In Search of Endemics in Colombia

At the end of February, our newest travel consultant Amy Englert got the chance to escape from Colorado’s cold weather and visit the remote Chocó department in Colombia.  Chocó is located along the northwestern coastline, and makes up some of the world’s rainiest lowlands, receiving between 300 and 500 inches of rainfall yearly.  This area has been isolated both geographically and politically: there are no roads connecting the interior of the country to the thick rainforests of the department, and up until fairly recently, conflicts in the area made it a rarely visited destination.  All of these factors have combined to create an incredibly diverse and relatively unspoiled destination for birders, whale-watchers, and nature lovers alike.  Endemic species are those that are found only in a specific area, and some estimates have given the percentage of endemism in Chocó as high as 40% – ensuring a unique wildlife watching experience! 

 

Welcome to the small village of Termales in Colombia's Choco Department.
Welcome to the small village of Termales in Colombia’s Choco Department.
Walking through the town of Termales, Colombia after a rain.
Walking through the town of Termales, Colombia after a rain.

Our group sighted a notable endemic on this trip, the harlequin poison frog (Oophaga histrionica).  This rare frog is commonly seen on a hiking trail from the small village of Termales to a local waterfall.  The night before the hike was scheduled, it rained all night and cleared in the morning, creating perfect conditions for frog spotting.  We headed out on the trail, with prior instruction to stay on the trail, and not move any of the vegetation just off the trail, as the frogs are highly territorial and susceptible to disturbance.  We heard the characteristic piping song of the male frogs long before we spotted any, as well as sighting several less ostentatiously colored species.  After hiking for about an hour, we saw our first harlequin frog.  Though only a few inches long, they are easily spotted in the leaf litter due to their conspicuous red and black patterning.

Spotting a harlequin poison frog, a notable endemic in Colombia's Choco department.
Spotting a harlequin poison frog, a notable endemic in Colombia’s Choco department.

The natural history of these frogs is reflected in the genus name, oophagia, meaning “egg-eater.”  After the female lays viable eggs in the leaf litter, the tadpoles hatch and are carried to a water source, typically inside of a bromeliad.  The tadpoles are obligate egg-eaters, and the female frog will continue to lay unfertilized eggs for the tadpoles to eat until they metamorphose into adult frogs.  The adult frogs are used by the indigenous Emberá people to tip their arrows, used for both hunting and defense.  The toxin present on the skin of poison dart frogs is a potent deterrent against predation and helps to explain both their unmistakable warning coloration and their fairly brazen diurnal behavior.  All of this together makes for a fascinating amphibian-watching hike in El Chocó.

Harlequin poison frog in Colombia.
Harlequin poison frog in Colombia.