The Red List Index of species survival:
What is the long-term impact of Durrell’s conservation programmes on its target species’ chances of survival?
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Changes in the chances of Survival
The Red List Index (RLI) measures the impact of Durrell’s conservation work.
It compares the way the overall extinction risk of 17 of its target mammal, bird and amphibian species has changed to a theoretical scenario in which conservation has not taken place. The RLI measures changes in the chances of survival of each species by tracking its movement over time through IUCN Red List categories of extinction risk. These categories are assigned by independent experts who follow the rigorous and authoritative IUCN Red List assessment process. Eight of Durrell’s target species have moved into lower Red List categories since 1988 – six Mauritian birds, the Golden Lion Tamarin and the Mallorcan Midwife Toad – meaning their numbers have significantly increased and therefore their risk of extinction decreased.
This has driven a striking upward trendin the RLI, demonstrating that Durrell’s programmes are moving many species away from extinction. Without conservation efforts, some of these species would almost certainly have gone extinct in the wild, and overall our species would have been in far worse shape than they are today.
A 2010 scientific paper in a world-leading journal showed that, at a global level since the 1980s, 63 mammal, bird and amphibian species have moved down the Red List because of conservation.
That means Durrell and its partners have led or contributed to more than 10% of these globally significant improvements in the status of species.
With intervention
Durrell's programmes have resulted in an overall 49% increase in the chances of survival of our target species as their populations recover back to safer levels
Without intervention
Without Durrell's programmes, we predict an overall 23% decrease in the chances of survival of our target species, including at least five species that would have gone extinct and many more that would have declined in numbers
Durrell Red List Index
Echo parakeet
Red List Rating:
Endangered
Without Conservation:
Extinct
Durrell's Impacts
In the 1980s, the echo parakeet of Mauritius numbered just 12 individuals and would probably have gone extinct without intensive hands-on conservation by Durrell and its partner, the Mauritian Wildlife Foundation. Durrell led the first captive breeding programme outside Mauritius and supported reintroductions of birds back to the wild, nest box provision and supplementary feeding allowing the parakeet to increase numbers in the wild to 500 birds today.
Durrell Red List Index
Malagasy giant jumping rat
Red List Rating:
Endangered
Without Conservation:
Critically Endangered
Durrell's Impacts
Restricted to in a single dry forest in western Madagascar which was dwindling fast due to agricultural encroachment and logging, the giant jumping rat faced a very uncertain future. Durrell played a key role in the establishment of the Menabe Antimea protected area and led schemes to improve the livelihoods of local communties to reduce pressure on the forest, thereby arresting population declines and likely avoiding the species being uplisted to Critically Endangered.
Durrell Red List Index
Mallorcan midwife toad
Red List Rating:
Vulnerable
Without Conservation:
Critically Endangered
Durrell's Impacts
Once known only from a fossil, this amphibian has been downlisted from Critically Endangered to Vulnerable thanks to a major collaborative conservation effort in the 1980s and 90s. Durrell was invited by the Mallorcan Government to lead the essential captive breeding programme that supplied animals for release back into the wild and driving the recovery of the wild population.
Durrell Red List Index
Mauritius kestrel
Red List Rating:
Vulnerable
Without Conservation:
Extinct
Durrell's Impacts
After centuries of population decline, by the 1970s only 4 Mauritius kestrels survived and the species would have been extinct today were it not for intensive hands-on conservation by Durrell and its partner the Mauritian Wildlife Foundation. A successful captive breeding and reintroduction programme, provision of next boxes and invasive predator control has recovered the species to 400 birds today, which is now recognised as one of the icons of global bird conservation.
Durrell Red List Index
Narrow striped mongoose
Red List Rating:
Vulnerable
Without Conservation:
Vulnerable
Durrell's Impacts
Found only in the dry forests of western Madagascar, the little-known narrow-striped mongoose is threatened by deforestation and is currently Vulnerable on the IUCN Red List. Durrell played a key role in the establishment of the Menabe Antimea protected area, which includes a programme to improve the livelihoods of local forest-dependent communties, protecting at least 30% of the global range of this species.
Durrell Red List Index
Olive white eye
Red List Rating:
Critically Endangered
Without Conservation:
Critically Endangered
Durrell's Impacts
Since 1990, Durrell have supported the Mauritian Wildlife Foundation to conduct captive breeding and release programmes, along with invasive predator control, to conserve the Critically Endangered species. The olive-white eye is now recovering in the Black River Gorges National Park and has been re-introduced onto an offshore island.
Durrell Red List Index
Pink pigeon
Red List Rating:
Endangered
Without Conservation:
Extinct in the Wild
Durrell's Impacts
The pink pigeon of Mauritius once numbered just 16 birds and would probably have gone extinct in the wild without intensive hands-on conservation by Durrell and its partner, the Mauritian Wildlife Foundation. Durrell led the first captive breeding programme outside Mauritius, supporting the reintroduction of birds back to the wild which, combined with invasive predator control and supplementary feeding, have increased numbers in the wild to 400 today.
Durrell Red List Index
Pygmy hog
Red List Rating:
Critically Endangered
Without Conservation:
Critically Endangered
Durrell's Impacts
Once thought to be extinct, a small population of the Critically Endangered pygmy hog was rediscovered in a single patch of grassland in the Himalayan foothills of Assam. Durrell established and manages the only captive breeding programme in existence, thereby safeguarding the species, and supplying animals for reintroduction and the re-establishment of populations at two new sites.
Durrell Red List Index
Rodrigues fruit bat
Red List Rating:
Critically Endangered
Without Conservation:
Critically Endangered
Durrell's Impacts
After decades of forest loss and hunting, by the 1970s the Rodrigues fruitbat had dwindled to 100 or so individuals. Durrell established the first captive population of this Critically Endangered species and supported our local parter, the Mauritian Wildlife Foundation, in forest restoration and close monitoring of the species enabling the fruitbat to recover to an impressive 10,000 individuals today.
Durrell Red List Index
Alaotran gentle lemur
Red List Rating:
Critically Endangered
Without Conservation:
Critically Endangered
Durrell's Impacts
The Alaotran gentle lemur is the only primate in the world to live exlusively in a wetland but agricultural encroachment and fires have driven severe declines in its sole marsh habitat. Durrell implemented improved protection from poaching and led development of the Lake Alaotra protected area, along with improving local livelihoods and fisheries management, in order to reduce pressures on the marsh. Without these measures this Critically Endangered lemur would be in a much worse state today.
Durrell Red List Index
Mauritius fody
Red List Rating:
Endangered
Without Conservation:
Critically Endangered
Durrell's Impacts
Since 1989, Durrell have supported the Mauritian Wildlife Foundation to conduct captive breeding and release programmes along with invasive predator control to recover the Mauritius fody from just 100 breeding pairs to a much safer number today and is now classified as Endangered. Without these interventions this species would have remained as Critically Endangered.
Durrell Red List Index
Madagascar teal
Red List Rating:
Endangered
Without Conservation:
Endangered
Durrell's Impacts
This duck was once so poorly studied no one even knew where they bred. In the 1990s, Durrell led the first ever surveys of this species identifying the mangrove forests hugging the west coast of Madagascar as vital nesting habitats and in desperate need of protection. Since then Durrell has worked with local communitiues and charities to protect key nesting and wintering sites in attempt to halt the decline of this species.
Durrell Red List Index
Meller's duck
Red List Rating:
Endangered
Without Conservation:
Endangered
Durrell's Impacts
An exceptionally poorly known species, Durrell have led vital surveys of the Mellers duck in very remote highland areas of Madagascar to locate key breeding sites. Since then Durrell has worked with local communitiues and charities to protect these sites in attempt to halt the decline of this species.
Durrell Red List Index
Rodrigues fody
Red List Rating:
Near Threatened
Without Conservation:
Extinct in the Wild
Durrell's Impacts
Destruction of its forest habitat and impacts of invasive species reduced the Rodrigues fody to just 6 pairs in the wild and on the brink of extinction. Durrell initiated the first captive breeding programme to safeguard the species and since the 1980s has supported the Mauritian Wildlife Foundation to restore forests, enabling the the species to recover to 8000 birds today. In 2013, the Rodriges fody was downlisted to Near Threatened representing one of the largest recoveries of any threatened bird.
Durrell Red List Index
Rodrigues warbler
Red List Rating:
Near Threatened
Without Conservation:
Extinct
Durrell's Impacts
The Rodrigues warbler once numbered just 8 pairs and would likely be extinct without the sustained protection and restoration of key forest habitats. Since the 1980s, Durrell has supported the Mauritian Wildlife Foundation to restore forests and closely monitor the warbler population which now numbers 4,000. In 2013, it was downlisted to Near Threatened as a result of these efforts
Durrell Red List Index
Black lion tamarin
Red List Rating:
Endangered
Without Conservation:
Endangered
Durrell's Impacts
Almost entirely restricted to a single national park in the Atlantic rainforests of Brazil, this tamarin has lost most of its range through deforestation. In the 1960s, Durrell established the first captive population outside of Brazil and with our local partner, IPE, carried out the first reintroductions back into the wild. We have since worked closely with local partners to develop key conservation insitutions and skills to drive the recovery of this species which is now recognised as Endangered.
Durrell Red List Index
Golden lion tamarin
Red List Rating:
Endangered
Without Conservation:
Endangered
Durrell's Impacts
Once listed as Critically Endangered, the Golden lion tamarin has lost almost 98% of its original Atlantic rainforest habitat in Brazil. Durrell established the first captive breeding programme outside Brazil and has since worked closely with local partners to develop key conservation skills to drive the recovery of this species which has since been downlisted to Endangered.