麻豆传媒高清版

Nature鈥檚 Backbone at Risk

Madagascar's flying fox has recently been identified as threatened with extinction due to over hunting. 麻豆传媒高清版 is working with partners in Madagascar to reduce the pressure on populations: (photo credit: Evan Bowen-Jones) The most comprehensive assessment of the world鈥檚 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 today at the 10^th Conference of the Parties to the Convention on Biological Diversity, CBD, in Nagoya, Japan.

The study, published in the international journal Science (The Impact of Conservation on the Status of the World's Vertebrates Hoffmann et al. 26 October 2010: science.1194442v1-1194442
DOI: 10.1126/science.1194442 ), used data for 25,000 species from The IUCN Red List of Threatened Species鈩�, to investigate the status of the world鈥檚 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.

鈥淭he 鈥榖ackbone鈥� of biodiversity is being eroded,鈥� said the great American ecologist and writer Professor Edward O. Wilson, at Harvard University. 鈥淥ne 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.鈥�

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 at least an additional 20 percent if conservation action had not been taken.

鈥淭his study effectively illustrates why we need to invest in conservation projects鈥� said Dr Richard Jenkins, post-doctoral researcher at 麻豆传媒高清版 and an author on the study. 鈥溌槎勾�媒高清版 is working in Madagascar, funded by the UK government's Darwin Initiative, to stem the illegal hunting of protected species for food."

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鈥檚 Horse, Equus ferus, in Mongolia.

Conservation efforts have been particularly successful at combatting invasive alien species on islands. The global population of Seychelles Magpie-robin, Copsychus sechellarum, increased from fewer than 15 birds in 1965 to 180 in 2006 through control of introduced predators, like 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.

In South America, protected areas and a combination of the Convention on International Trade in Endangered Species (CITES) and the Vicu帽a Convention helped spark the recovery of the Vicu帽a Vicugna vicugna. Similarly, legislation enacted to ban commercial whaling has seen the Humpback Whale, Megaptera novaeangliae, move from Vulnerable to Least Concern. Unfortunately, very few amphibians have yet shown signs of recovery, but international efforts are escalating, including a programme to reintroduce the Kihansi Spray Toad, Nectophrynoides asperginis, back into the wild in Tanzania.

The authors caution that their study represents only a minimum estimate of the true impact of conservation, highlighting that some 9% 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 鈥� from extremely low current levels - to make the objectives of the Convention achievable.

鈥淭his is clear evidence for why we absolutely must emerge from Nagoya with a strategic plan of action to direct our efforts for biodiversity in the coming decade鈥� said Julia Marton-Lef猫vre, Director General of IUCN. 鈥淚t is a clarion call for all of us 鈥� governments, businesses, citizens 鈥� to mobilize resources and drive the action required. Conservation does work -- but it needs our support, and it needs it fast!鈥�

The paper highlights that the percentage of species threatened among vertebrates ranges from 13 percent  of birds to 41 percent of amphibians. Although the study focused on vertebrates, it also reports on the levels of threat among several other groups assessed for the IUCN Red List, including14 percent of seagrasses, 32 percent of freshwater crayfish, and 33 percent of reef-building corals.

The level of threat among cycads is extremely critical, with 63 percent threatened with extinction. Cycads, the most ancient group of seed plants alive today, are subject to extremely high levels of illegal harvesting and trade, and are in danger of going the same way as the dinosaurs.

Recently, a UN-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.

Failure to meet the internationally agreed 2010 target to reduce biodiversity loss does not mean that conservation efforts have been in vain, as this study demonstrates. However, the erosion of biodiversity has reached such dangerous levels that we cannot afford to fail again. Ambitious targets are needed for 2020, and to meet them will require urgent and concerted action on a greatly expanded scale. It is time for the world鈥檚 Governments, meeting in Nagoya, to rise effectively to this global challenge. 

Publication date: 27 October 2010