Aye-aye and possums top list of mammals we should focus on saving

Biologists have come up with improved ways to prioritize conservation efforts based on how unique a species is and how endangered its relatives are.

To Michael Le Paige

Zoological Society of London (ZSL).

In 2007, ZSL researchers suggested that species should be prioritized based on how unique they are and how endangered they are. They developed a method called EDGE. This represents an evolutionarily different and globally endangered species.

The idea is that it is more important to preserve different branches of the tree of life than different twigs of the same branch. Species with no relatives going extinct suffer more losses than species with many relatives going extinct.

ZSL’s Rikki Gumbs said: For example, in 2018, her EDGE list of reptiles highlighted the uniqueness of Australian turtles, such as Mary River turtles (Elusor macrurus), which diverged from other species 40 million years ago. He says this has prompted more to be done to protect them.

However, I ran into some issues with EDGE. For example, because so little is known about some species, biologists often have to make guesses when he tries to calculate an EDGE score, he says Gumbs. And if a species has endangered relatives, those relatives should take precedence over other non-endangered species, he says.

Gums and his colleagues therefore developed an improved version of EDGE that better takes into account uncertainties and factors such as the status of endangered relatives, and applied it first to mammals. Did.

The improved system doesn’t make much of a difference in the top 100. It contains 97 of the same species, but in a different order. In his EDGE mammal list for 2007, the mountain pygmy possum (small baramis), aye (Dowbentonia madagascariensis) and the leadbeater possum (Gymnoberideus ledoviteri) were ranked 28, 16, and 54, respectively. These revised rankings are due to changes in our knowledge rather than revised techniques.

But the new method makes a big difference further down the rankings.

White or Yangtze River dolphin (Lipotes bexilifer) topped the first EDGE list. It is now believed to be extinct.

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