THE giants of the Madagascan forests, such as koala lemurs, each the size of a gorilla, died out half a millennium ago. But they left in their wake a host of tree species whose habitats are shrinking now they have no animals to disperse their seeds in droppings. With other lemurs critically endangered, swathes of Madagascar’s unique flora are living on borrowed time.
Sarah Federman of Yale University and her colleagues have linked lemur extinctions to the precarious future of the island’s large-seeded plants.
They found that the disappearance of 17 species of fruit-eating lemurs in the past few centuries has reduced the ability of lemurs to disperse seeds by up to a third. This means many of the island’s plants have lost their primary means of propagation.
The team discovered this by looking at the teeth and jaws of the extinct lemurs, to work out their diet. The giant lemurs ate large fruit with large seeds, which they then excreted widely across the island. With the big lemurs gone, some plants are in real trouble because their seeds are too big for other animals to eat (PNAS, DOI: 10/1073/pnas.1523825113).
Others are in danger – many trees are now dependent on the two largest surviving lemurs that are “unique and irreplaceable,” says Federman. Both are also critically endangered. The affected trees include most of the 33 species of Canarium hardwoods dominating the island’s forests. So, conserving lemurs should be an urgent priority, says Federman.
“This study is of utmost importance,” says Christoph Schwitzer of Bristol Zoo, UK, a member of the IUCN specialist group for primates. “It shows that protecting lemurs means protecting Madagascar’s forest ecosystems.”
This article appeared in print under the headline “Lemur survival key to stopping forest demise”