Most modern zoos claim to play a crucial role in conservation, yet very few are able to measure or report the difference they make to threatened species. This week, world-renowned conservation charity and Amphibian Survival Alliance Partner Durrell Wildlife Conservation Trust launched a series of pioneering online performance indicators, known as the ‘Durrell Index’, designed to measure and communicate the organisation’s achievements in preventing species extinctions.

[vc_row][vc_column width=”2/3″][text_output]One of the most important impact indicators in the Durrell Index is the International Union for Conservation of Nature (IUCN) ‘Red List Index of Species Survival’. This indicator tracks the conservation status of a set of Durrell’s target species over time, compared to a predicted ‘no conservation’ scenario. The results showed that eight species have moved into lower, less-threatened Red List categories since 1988, meaning their risk of extinction decreased as a result of Durrell’s conservation efforts in partnership with in-country collaborators. An example is the Mallorcan midwife toad, re-graded from ‘Critically Endangered’ to ‘Vulnerable’ between 1996 and 2004 as a result of captive breeding and reintroduction combined with control of introduced species. This is the first use of this globally-recognised indicator to evaluate the impact of a conservation organisation and is outlined in a recently published research paper in the journal Biological Conservation.

According to IUCN-led research, only 63 bird, mammal and amphibian species have been re-graded to a less threatened status on the Red List as a result of conservation. Of these, 12% are Durrell-led or supported projects; this represents a huge ‘market share’ of success for a relatively small charity.

Richard Young, Head of Conservation Science at Durrell said, “The Durrell Index shows that conservation focussed zoos can make a real, significant and measurable difference and can save species from extinction. Our founder Gerald Durrell pioneered the role of zoos in conservation and with the Durrell Index we are spearheading how zoos can measure their conservation impact”.[/text_output][/vc_column][vc_column width=”1/3″]


The mountain chicken (Leptodactylus fallax)

[/text_output][line][text_output]For more information please visit

Young, R.P., Hudson, M. A., Terry, A. M.R., et al. (2014) Accounting for conservation: Using the IUCN Red List Index to evaluate the impact of a conservation organization. Biological Conservation. 180: 84–96. DOI:10.1016/j.biocon.2014.09.039.[/text_output][/vc_column][/vc_row]

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