The 22nd of May is the International day for Biological Diversity, and this year the theme is Island Biodiversity. Islands house a disproportionate amount of the world’s biodiversity: although less than 5% of the world’s land area, they are home to over 20% of the planet’s terrestrial biodiversity, and in the last 500 years 80% of vertebrate extinctions have been on islands. Invasive species have been implicated in over half of these extinctions.
The Threatened Island Biodiversity database lists over 500 islands with critically endangered species (the highest level of threat on the IUCN red list), over 80% of which have invasive species present. Ten critically endangered insular bird species have been saved from extinction by direct conservation intervention, including the Tahiti monarch (Pomarea tigra), coincidentally the 2014 winner of the first Birdlife International People’s Choice Award.
This year’s theme was chosen because 2014 is also the International Year of Small Island Developing States (SIDS). It is certainly not just conincidence that these two have occurred together. The fate of island biodiversity and small island states are intimately entwined, mutually reinforcing one another. Threats such as climate change do not discriminate between the livelihoods of humans, fauna or flora. To address such threats requires the empowerment of island communities, who can be confident they have the support of their big continental brothers and sisters, to work towards better livelihoods for themselves, and all the cultural and biological diversity under their custodianship.