Muddy, mosquito-ridden mangrove swamps are difficult places to live. Few species of plants or invertebrates bother. As a result there aren’t many specialist mangrove-dwellers among the world’s mammals, and these forests, highly threatened halfway houses between land and sea, tend to be neglected by wildlife conservationists.
But what about non-specialist animals? Do species more typically found in regular forests also use mangroves if the opportunity arises? Surprisingly, that’s a question we have very few answers to, but one I set out to investigate for one of the most charismatic and threatened of all animal groups: Madagascar’s lemurs. And I was amazed by what I found.
I have long been fascinated by both mangroves and lemurs, but these two interests collided one magical evening in March 2015. My wife and I were carrying out a bird survey at Antsahampano, deep in the mangroves of north-west Madagascar, for the marine conservation organisation Blue Ventures. We camped the night on a small sandy island offshore and, as we always do, went for a night walk after dinner to see what we could find.
Louise Jasper, Author provided
We certainly weren’t expecting any lemurs – after all, we were about 3km from the nearest dry land, with nothing but mangroves in between – and we saw little but crabs for most of the way. But just as the rain started falling and we turned back for camp, we spotted the characteristic glimmer of a mammal’s eyes high in a tree, reflected in our torchlight. A fruit bat, I assumed, but as we got closer it turned out to be a northern giant mouse lemur, an endangered species with the wonderful scientific name Mirza zaza, found only in this part of Madagascar.
We were astonished. A lemur? All the way out here in the mangrove? I had already searched the existing literature and knew that only four lemur species had ever been reported in mangroves before, so this sighting really pricked my interest. It occurred to me that perhaps others had seen lemurs in mangroves too but their observations might never have made it into the scientific literature. And so I decided to crowd source.