16 May Celebrating Endangered Species Day! Endemic and Endangered: Stories of a frog and a tanager.
Blogpost written by Alejandra Rojas, Naturalist Guide and Avian Program Coordinator
Photo 1: The endemic & endangered Golfodulcean Poison-arrow Frog and Black-cheeked Ant Tanager (Photo credit: Manuel Sanchez Mendoza)
What does a Golfodulcean Poison-arrow Frog and a Black-cheeked Ant-tanager have in common?
Not only are they endemic to the Osa Peninsula in Costa Rica, but they are also endangered – a term used to describe when there are so few individuals surviving that the species is at risk of no longer existing in the wild. There are many reasons that could drive a species to this status, including: habitat loss, illegal pet trade, introduction of exotic species, diseases, illegal hunting or overfishing.
Why does the Osa have so many endemic species?
Because of its geological formation where it evolved as an island before merging with the Costa Rica mainland (nearly 2 million years ago), the Osa Peninsula harbors a high level of endemic species. Endemic species are those which are found exclusively in one location in the world. This endemism, together with the immense concentration of life forms found in this region, is the reason why the Osa is globally known as a biodiversity hotspot and has such an important conservation value.
Why are these endemic species endangered?
Although the Golfodulcean Poison-arrow Frog and the Black-cheeked Ant-tanager can be found in areas close to the Osa Peninsula, populations are isolated, and in the case of the frogs, are considered a rarity. According to the IUCN Red List of Threatened Species (2017) both species are endangered because of their small distribution range, confined to protected areas, where logging and continuously habitat loss around these areas are the major threats to both species nowadays. In the case of the frog, water pollution due to gold mining in the Osa is also a huge threat.
What is it like to experience these endemic & endangered species?
If you have never had the chance to explore nature in the Osa and see these animals, I invite you to go on an imaginary hike: It´s 5:15 am and we embrace an early morning hike into the rainforest. Binoculars in hand, a nice flute-like sound indulge our senses: it is the Black-cheeked Ant-tanager, but we have not seen it yet. This bird performs this particular song only in the early morning, sometimes accompanied by the howler monkeys´ chorus.
Time passes and a chatter-like sound captures our attention. Should we look up to the canopy? No, we better focus in the understory, where this species inhabit. As all tanagers, the Black-cheeked Ant-tanager fly in family groups and forage in the lower levels of the forest in search of small arthropods and fruits- a behavior that makes them important for controlling defoliating arthropods and also for dispersing seeds. Wait! Be careful with these bunch of army ants passing through the trail; let´s find a good place to enjoy the show: the Black-cheeked Ant-tanagers are following the “ant swarm” with a mixed flock. We watch for 10 minutes until they disappear in the vegetation, following the path of the ants.
Photo 2: Black-cheeked Ant Tanager (Photo credit: Manuel Sanchez Mendoza)
As we keep walking in the rainforest another sound captures our attention: the Golfodulcean Poison-arrow frog- a diurnal species (active both day and night). We can hear two calls but they are far away; maybe if we move towards a creek we can find them. Indeed, as we approach a small creek, we spot two males calling together on top of a log! These frogs are very territorial and we are witnessing a territorial display. Their colors (known in biology as aposematic coloration) are warning us that they are highly toxic. Continuing our walk along the creek, we find another male, but this time carrying tiny larvae on his back. He will soon deposit them in the water for their next life stage. Our hike concludes and we are thrilled to have successfully found these two endangered species that can only be seen in the Osa.
Photo 3: The endemic & endangered Golfodulcean Poison-arrow Frog (Photo credit: Manuel Sanchez Mendoz
Why are endangered species important?
Experiencing nature is one way we can understand the importance of protecting endangered species. Each species, endangered or not, has a role to play in the greater ecosystem, whether by dispersing seeds, controlling other species, or by directly helping other species maintain the ecosystem health. These two endemic species- the Golfodulcean Poison-arrow Frog and the Black-cheeked Ant-tanager- are also important because they act as umbrella species. This means that if we protect their habitat we are also protecting the habitat of other important species, including other endangered animals and plants as the Jaguar (Panthera onca), the Scarlet macaw (Ara macao) and the Nazareno or Purpleheart (Peltogyne purpurea) found in the Osa.
Is it too late? Not yet!
Do we still have time to save the Golfodulcean Poison-arrow Frog and the Black-cheeked Ant-tanager? Yes, but we need ongoing efforts to conserve the vital ecosystems that support these animals and the surrounding biodiversity. Because these species are restricted to protected areas and they know no political boundaries, it is even more important to prioritize the buffer areas, forest patches and biological corridors that connect their habitat and are the last stronghold for their survival.
Please help Osa Conservation continue to save these amazing species and so much more! 100% of your donations goes toward helping conserve the habitats and ecosystems on which these species and so many more rely! You can visit our page here to make a donation or visit here to learn about visiting the Osa and seeing these incredible creatures for yourself! Every effort counts!