BONN, GERMANY - While nearly one million species are currently at risk of extinction, the United Nations University (UNU) in Bonn is drawing attention to “co-extinctions”: the chain reaction occurring when the complete disappearance of one species affects another.

The issue is in the spotlight ahead of the International Day for Biological Diversity, observed annually on 22 May, and covered in the most recent edition of UNU’s Interconnected Disaster Risks report.

Among the animals at risk is the gopher tortoise, one of the oldest living species on the planet. This tragic story of biodiversity loss is unfolding at the heart of the coastal plains of the southern United States.

Ecosystem ‘architect’

Their reduced number is not just problematic for the survival of the tortoise as a species, however, as these charismatic creatures also play a vital role in preserving the delicate balance of their coastal realm.

Gopher tortoises are not merely occupants of their habitat; they are architects, sculpting ecosystems and providing sanctuaries for over 350 other species. With their front legs functioning like shovels, they dig burrows that range in size from 20 to 30 feet (6 to 9 metres) long and from 6 to 8 feet (1.8 to 2.5 metres) deep.

From small insects to larger amphibians, each organism plays a vital role in the ecosystem's intricate web of life these burrows provide. For some, the burrows of the gopher tortoise are a safe haven for breeding and nurturing offspring, while for others, they offer respite from predators and the elements.

Should the gopher tortoise vanish, it is likely a domino effect would be felt throughout the ecosystem.

Among the most vulnerable is the critically endangered dusky gopher frog, a species already teetering on the brink of extinction. Reliant on the tortoise's burrows for shelter and survival, the disappearance of the tortoise would most likely put the frog’s survival at risk too.