Lagos — Scientists at the recently concluded 10th conference of the parties to the convention on biological diversity (CBD) in Nagoya, Japan, have warned that the most comprehensive assessment of the world's vertebrates confirms an extinction crisis with one-fifth of species threatened.
However, the situation would be worse were it not for current global conservation efforts, according to a study launched at the 10th Conference of the Parties to the Convention on Biological Diversity, CBD, in Nagoya, Japan.
The study, to be published in the international journal Science, used data for 25,000 species from The IUCN Red List of Threatened Speciesâ„¢, to investigate the status of the world's vertebrates (mammals, birds, amphibians, reptiles and fishes) and how this status has changed over time. The results show that, on average, 50 species of mammal, bird and amphibian move closer to extinction each year due to the impacts of agricultural expansion, logging, over-exploitation and invasive alien species.
"The 'backbone' of biodiversity is being eroded," says the emminent American ecologist and writer Professor Edward O. Wilson, at Harvard University. "One small step up the Red List is one giant leap forward towards extinction. This is just a small window on the global losses currently taking place."
Southeast Asia has experienced the most dramatic recent losses, largely driven by the planting of export crops like oil palm, commercial hardwood timber operations, agricultural conversion to rice paddies and unsustainable hunting. Parts of Central America, the tropical Andes of South America, and even Australia, have also all experienced marked losses, in particular due to the impact of the deadly chytrid fungus on amphibians.
Whilst the study confirms previous reports of continued losses in biodiversity, it is the first to present clear evidence of the positive impact of conservation efforts around the globe. Results show that the status of biodiversity would have declined by nearly 20 percent if conservation action had not been taken.
"History has shown us that conservation can achieve the impossible, as anyone who knows the story of the White Rhinoceros in southern Africa is aware," says Dr Simon Stuart, Chair of IUCN's Species Survival Commission and an author on the study. "But this is the first time we can demonstrate the aggregated positive impact of these successes on the state of the environment."
The study highlights 64 mammal, bird and amphibian species that have improved in status due to successful conservation action. This includes three species that were extinct in the wild and have since been re-introduced back to nature: the California Condor, Gymnogyps californianus, and the Black-footed Ferret, Mustela nigripes, in the United States, and Przewalski's Horse, Equus ferus, in Mongolia.
Conservation efforts have been particularly successful at combatting invasive alien species on islands. The global population of the Seychelles Magpie-robin, Copsychus sechellarum, increased from fewer than 15 birds in 1965 to 180 in 2006 through control of introduced predators, like the Brown Rat, Rattus norvegicus, and captive-breeding and re-introduction programmes. On Mauritius, six bird species have undergone recoveries in status, including the Mauritius Kestrel, Falco punctatus, whose population has increased from just four birds in 1974 to nearly 1,000.
The authors caution that their study represents only a minimum estimate of the true impact of conservation, highlighting that some nine percent of threatened species have increasing populations. Their results show that conservation works, given resources and commitment. They also show that global responses will need to be substantially scaled up, because the current level of conservation action is outweighed by the magnitude of threat. In this light, policy-makers at the CBD meeting in Nagoya have been calling for a very significant increase in resources - from extremely low current levels - to make the objectives of the Convention achievable.
Recently, a United Nations-sponsored study called The Economics of Ecosystems and Biodiversity (TEEB) calculated the cost of losing nature at $2-5 trillion per year, predominantly in poorer parts of the world. A recent study found one-fifth of more than 5,000 freshwater species in Africa are threatened, putting the livelihoods of millions of people dependent on these vital resources at risk.