Branson’s plan to save lemurs is turning heads.

If you build Madagascar’s lemurs a new home, will they come? And can you trust them not to trash the place?

Sir Richard Branson, private moon shot funder, Virgin Group kingpin, kooky billionaire du jour, has been turning heads with his announcement that he plans to import 30 ring-tailed lemurs from zoos to one of his privately owned islands in the British Virgin Islands. The idea is to give endangered or threatened species a new place to live and breed—Madagascar’s civil war has meant a resurgence in lemur habitat loss, and ring-taileds are listed as “near threatened”—but biologists and conservationists are pointing out how Branson could be doing the island’s native ecosystem a serious disservice. “It’s pretty weird,” Simon Stuart, chair of the International Union for the Conservation of Nature’s Species Survival Commission, told the BBC. “What else lives on the island, and how might they be affected?”

On the one hand, it’s rather charming that Branson has such a hands-on approach to problems of conservation (he’s also founded the Virgin Green Fund to tackle next-generation fuel development), which are often depressingly intractable. But the ...