Clarion Island is the furthest and oldest member of the Revillagigedo Archipelago, a small chain of islands located off the western coast of Mexico. Recent discoveries about its endemic species have galvanized worldwide attention. Spiny-Tailed Iguanas, of the genus Ctenosaura, have a particularly interesting one. They extend human presence in the Americas back some 425,000 years. This surprising revelation speaks to the complex evolutionary backstory of these reptiles. More than a sea change, it’s a correction to decades worth of bad wildlife management assumptions on the island.
Clarion Island, thought to be over five million years old, is a juxtaposition of geological formations and biodiversity. The island is home to some 15 endemic species, including snakes, lizards and scores of birds. The Revillagigedo Archipelago supports an incredibly diverse marine life, attracting the attention of both scientists and conservationists alike. This marine ecosystem is unique when compared to other famous ecosystems such as the Galapagos and Hawaiian Islands.
Unique Ecosystem of Clarion Island
Clarion Island’s ecosystem has developed independently, giving rise to a unique assemblage of wildlife. The island had previously been heavily vegetated by dense stands of prickly-pear cactus. Getting through that kind of environment took jungle knives to do so. This special ecosystem thus allowed a multitude of species to thrive, among them the Spiny-Tailed Iguanas.
Recent studies utilizing DNA analyses have indicated that the Spiny-Tailed Iguanas diverged from their mainland counterparts approximately 425,000 years ago. This divergence shows that iguanas naturally dispersed to the island. They probably floated on mats of vegetation when the water was high. These unexpected discoveries continue to shine a light on both the persistence and plasticity of species living in fragmented landscapes.
The introduction of non-native species, both intentional and unintentional, has wreaked havoc on Clarion Island’s delicate island ecosystem. In addition to the goats, the Mexican military introduced sheep, pigs, and rabbits while using the island as a military base in the 1970s. The introduction of these species razed thousands of acres of native vegetation. In response, Spiny-Tailed Iguanas found themselves in the public eye and their habitat was radically altered.
Impact of Introduced Species
The introduction of sheep and pigs brought to Clarion Island drastic ecological repercussions. With so much of the native vegetation wiped out, the dynamic of the ecosystem changed. The Spiny-Tailed Iguanas, which had initially stayed camouflaged beneath layers of thick vegetation, were suddenly unprotected and out in the open. This modification darkened calls about the alteration’s effect on the long-term survival of the iguana population.
In order to address these ecological issues, wildlife management actions on Clarion Island have centered on the control or eradication of non-native species. The program met its goal of eliminating sheep and pigs and has made significant progress towards eliminating the population of rabbits and iguanas. New genetic findings complicate this narrative. With the latest finding, Spiny-Tailed Iguanas join the ranks of the island’s unique, native wildlife. This unexpected finding should lead us to reconsider our existing management practices.
Bayesian evolutionary analyses reveal ancestral origin of iguanas’ lineage. In doing so, they made clear the ancient presence of these creatures on the island. These wisdoms are inspiring management masters to re-evaluate their conservation modus operandi. Realizing that these iguanas represent an important part of Clarion Island’s ecosystem requires a more balanced approach in the future.
Reassessing Wildlife Management
Recent findings on Spiny-Tailed Iguanas have ignited passionate debate between natural resource professionals. These days, their work is focused on understanding the iguanas’ role in the ecology of Clarion Island. Probably the biggest concern people had about these iguanas is that they were invasive, because just like other introduced species their populations were skyrocketing. Today, they’re considered an important component of the island’s unusual biodiversity.
Conservationists are examining Clarion Island’s deep history. They are determined to find the best possible solutions to protect the species and deal with the negative effects of introduced animals. In doing so, we hope to bring that balance back. Concurrently, we need to ensure other species’ survival that has lived inextricably to the island.