The Mount Lefo brush-furred mouse, Lophuromys eisentrauti, is a species that is simultaneously one of the most highly endangered and most likely to become extinct very soon. That’s primarily because it’s found only in one place: Mount Lefo, in western Cameroon. There’s also the Tahiti monarch Pomarea nigra, a bird from French Polynesia, and Turkey’s Bay Lycian salamander, Lyciasalamandra billae.

That’s according to University of Southern Denmark biologist Dalia A. Conde and John E. Fa of the Durrell Wildlife Conservation Trust. Together with their colleagues, the researchers identified fifteen vertebrate species that are in the most immediate danger: six amphibians (including Brazil’s Santa Cruz dwarf frog Physalaemus soaresi, pictured above), six birds, and three mammals.

The lists of “most at risk species” are too numerous to count, because everybody has a different manner of calculating risk. Conde and Fa’s analysis relies on the Alliance for Zero Extinction (AZE), which is a consortium of conservation-related organizations whose goal is to protect Critically Endangered and Endangered species that are restricted to single sites, like the Mount Lefo brush-furred mouse. The AZE has identified 920 mammals, birds, amphibians, reptiles, conifers, and reef-building corals in 588 key sites. “These are arguably the most irreplaceable category of important biodiversity conservation sites,” wrote the researchers last week in the journal Current Biology.

They argue that successful conservation of those species at those particular sites would represent important progress towards targets 11 and 12 of the 20 Aichi Biodiversity Targets, which were initially laid out by the United Nations Convention on Biological Diversity as goals for the year 2010. (Target 11 is the establishment of protected areas; target 12 is the prevention of species extinctions.)

To quantify the conservation needs for the vertebrate species listed by the AZE as priorities, which includes 157 mammals, 165 birds, 17 reptiles and 502 amphibians, the researchers calculated a conservation opportunity index (COI) for each species. Roughly speaking, that’s the cost in US dollars of achieving long-term conservation success for each species, both in its natural habitat and by establishing insurance populations in zoos and similar facilities. Factors involved include the costs of land acquisition and management, the likelihood of political uncertainty affecting conservation efforts in situ, the impact of urban expansion on natural habitats, and so on.

When it came to estimating the costs for the zoo populations, factors considered were the costs of managing populations of at least 500 individuals as well as measures of breeding expertise for each species, either already acquired or in need of development. The researchers point out that zoos’ role in conservation is critical, especially for amphibians, for whom insurance populations will likely be necessary to protect from the widespread chytrid fungus.

Fifteen species had a high COI value for both their natural habitat and for their zoo population. Fifteen others were low on both. The vast majority of species were mixed. That is, it is easier to protect the species in its natural range than in the zoo, or vice versa.

Here’s the shocker: the total annual cost for “effectively managing” all AZE vertebrates according to their analysis – 841 species – is just $1.18 billion dollars. To effectively manage all species in zoos would cost an extra $160 million annually, for a total of $1.34 billion. “Such investment for protecting high-biodiversity value sites and threatened species within them is trivial when compared to what governments spend globally each year on other sectors,” the researchers say. The United States alone budgeted approximately $3.5 trillion in 2014, for example.

But there’s also the factor of time: high opportunities are meaningless if a species goes extinct before they can be saved. Conde and Fa illustrate this with the Christmas Island pipistrelle (Pipistrellus murrayi). Despite having an extremely high COI (9.5 out of 10 for its natural habitat; 5 out of 10 for zoos), this AZE bat species became extinct. On the other hand, the point out that successes are also possible, naming the Mauritius kestrel (Falco punctatus), whooping crane (Grus americana), pygmy hog (Porcula salvania) and ploughshare tortoise (Astrochelys yniphora).

There are fewer than five years remaining until the Aichi target date of 2020. If that goal is to be met, recommendations and evaluations like this one need to be implemented, and soon. – Jason G. Goldman | 27 March 2015

Source: Dalia A. Conde. Fernando Colchero, Burak Güneralp, Markus Gusset, Ben Skolnik, Michael Parr, Onnie Byers, Kevin Johnson, Glyn Young, Nate Flesness, Hugh Possingham, and John E. Fa. (2015). Opportunities and costs for preventing vertebrate extinctions, Current Biology, 25 (6) R219-R221. DOI: 10.1016/j.cub.2015.01.048.

Header image: Santa Cruz dwarf frog via Ivan Sazima.

