Introduction: The fauna of mangroves basically reflects the convergence of two types of habitat, a sheltered marine muddy intertidal habitat and a terrestrial forest. In temperate areas, mangroves form fairly open, one layered forests; in tropical areas they may be open or closed, often multilayered with distinct zonation. The terrestrial fauna is to a large extent, restricted to the forest canopy and the marine fauna to the substrate and lower levels of the forest, so a horizontal partitioning of the two dominant kinds of fauna occurs. A third component, a freshwater fauna may be present along the margins of the mangroves in the upper reaches of the estuary.
Within the two major faunal components, subdivision occur. For the terrestrial fauna, this may be related to the zonation of the mangroves themselves. For example certain species of insects are restricted to particular mangrove trees, e.g. the butterfly Hypochrysops epicurus is restricted to Avicennia marina. The terrestrial fauna may also be affected by the type of vegetation adjacent, this may be Malaleuca/eucalypt forest, Juncus sedgelands, Malaleuca swamps; rainforests or bare salt plains. In some cases, mangroves may provide the only refuge for terrestrial species, in others they serve as a corridor linking adjacent habitats.