What is an EDGE Species? In our world, countless species have emerged and endured, evolving to withstand extinctions, and acquiring remarkable adaptations along the way. Take, for example, the tortoises and crocodiles, whose lineage stretches back to the era of dinosaurs. And let’s not forget our feathered friends, the birds, who have evolved and transformed from their direct dinosaur ancestors. Yet, amidst this diverse tapestry of life, there exist certain species that possess a unique and extraordinary distinction—they have few if any, relatives in their phylogenetic tree.
Recognizing the immense value of these evolutionary wonders, conservationists have come to understand that protecting endemic and scarce species alone is not sufficient. The species with rich evolutionary histories demand our attention, as they often hold not just ecological significance but also cultural importance. These extraordinary species are known as EDGE species, determined by their EDGE scores, a measure of their evolutionary distinctiveness.
What is an EDGE Species?
EDGE is an acronym for Evolutionarily Distinct and Globally Endangered Species. This scoring system considers a species’ high evolutionary distinctiveness and its conservation status based on the IUCN Red List. The evolutionary distinctiveness (ED) is calculated based on the species phylogeny, highlighting its uniqueness with its ancestors. It quantifies how genetically distinct a species is compared to others and represents the length of its evolutionary branch, indicating the amount of unique evolutionary history it possesses. A higher ED score indicates a more distinct and evolutionarily significant lineage.
The conservation status (GE) is determined by the IUCN Red List, with higher scores associated with more critical conservation statuses such as Critically Endangered, Endangered, or Vulnerable. Combining both values, the EDGE score is calculated, with the House mouse receiving the lowest score and the Yangtze River dolphin, declared functionally extinct, receiving the highest score.
As conservationists battle to find solutions for the concerning decline in species due to the alarming effects of anthropogenic activities, a question arises: what is worth more? It becomes a classic Noah’s Ark question. While most conservation efforts focus on protecting species with few individuals in the population or those declining at a rapid pace, or on preserving endemic species that highlight the richness of particular ecosystems or biodiversity, researchers have increasingly recognized that certain species stand out due to their unique ancestry and evolution. These species have a different story to tell and often play crucial roles as keystone species. Their uniqueness can have adverse effects on other species and the overall food web.
How are EDGE Species being conserved?
Stepping forward to safeguard these rare treasures, the EDGE of Existence program was initiated by the Zoological Society of London (ZSL) in January 2007. This pioneering conservation program aims to study, raise awareness, and provide support for the most unique and threatened creatures that contribute to the planet’s biodiversity. The program’s logo features the long-beaked echidna, symbolizing the dedication to protecting these exceptional species. The echidna is one of the most unique mammals, with a remarkable evolutionary history, including its ability to lay eggs.
To guide their efforts, the program utilizes EDGE scores and the updated EDGE2 protocol, which classify species into priority, EDGE, and focal categories. The top 100 EDGE species have been identified and catalogued in a comprehensive database, organized by class, including corals, amphibians, reptiles, sharks and rays, birds, and mammals. This data differentiates the program from the IUCN by incorporating EDGE scores and providing insights into the attention each species receives from conservation programs.
EDGE Fellowship
Each year, the EDGE of Existence program selects a focal species for intensive study and conservation support. They also offer a fellowship program, providing individuals with a two-year funding opportunity to work on EDGE species, with a particular emphasis on focal species. Preference is given to applicants from countries where the focal species are found, fostering local engagement and expertise. Furthermore, specific areas across five continents, such as the humid forests of Madagascar and the mountainous Western Ghats region of India, have been designated as EDGE zones.
The EDGE of Existence program has achieved significant milestones in its conservation efforts. They have focused on a diverse range of EDGE species, including the Hooded Grebe, Cuban Greater Funnel-eared bat, Cuban solenodon, Pygmy Sloth, Chinese giant salamander, Sagalla caecilian, Attenborough’s Long-beaked Echidna, Ganges River Dolphin, Red Slender Loris, Pygmy Hippo, and Wild Camels, among others.
Positive Conservation Stories of EDGE Species
These conservation efforts have resulted in noteworthy achievements. ZSL scientists rediscovered the Hispaniolan Solenodon in Haiti, a species previously thought to be extinct, in 2007. Additionally, ZSL EDGE scientists conducted the first close examination in 70 years of a subspecies of slender loris, and an online campaign by EDGE raised over £5,000 for a reforestation program to support loris populations in Sri Lanka. Other achievements include the successful prevention of the New Zealand government’s plans to mine 7,000 hectares of land, protecting the habitat of the priority EDGE amphibian, Archey’s frog, due to public pressure.
EDGE fellow Alfredo Hernández Díaz successfully bred the Critically Endangered Taylor’s salamander (Ambystoma taylori) in captivity, a species found exclusively in one lake in Mexico. EDGE Fellow Ashish Bashyal documented over 100 gharial hatchlings in Bardia National Park, Nepal, where breeding had not been observed since 1982.
Furthermore, Mexico EDGE Fellow Alejandro Calzada discovered a new population of the Critically Endangered granular salamander in Mexico, which resides within a protected area or reserve. EDGE Fellow Caleb Ofori Boateng published the discovery of a new species of Puddle frog, and EDGE Fellow Emmanuel Amoah recorded the first-ever West African slender-snouted crocodile nest in Ghana. EDGE Fellow Diana Renaud, as part of the EDGE Seychelles project, played a crucial role in establishing legislation to protect Sheath-tailed bats and their roosts.
These examples represent a fraction of the notable achievements made by the EDGE of Existence program in its conservation efforts. Through scientific research, public engagement, and international collaboration, they continue to have a significant impact on the protection and preservation of these unique and threatened species.
Conclusion
In conclusion, the conservation of EDGE species is vital for preserving their unique evolutionary histories and the rich tapestry of life on our planet. The EDGE of Existence program, led by the Zoological Society of London (ZSL), has made significant achievements in studying and protecting these exceptional species. Through initiatives such as identifying priority species, conducting research, and engaging local communities, the program has shown tangible results.
Help us Help Them! Think Wildlife Foundation is a non profit organization with various conservation initiatives. Our most prominent campaign is our Caring for Pari intiative. Pari is a rehabilitated elephant at the Wildlife SoS Hospital. 25% of the profits from our store are donated to the elephant hospital for Pari. Other than buying our wonderful merchandise, you could donate directly to our Caring For Pari fundraiser.
Written by: Amalendu Sasikumar Nair