Mangrove-dependent Animals Globally Threatened

Substantial numbers of terrestrial vertebrates are restricted to
mangrove forests. Many of these specialized species are listed as
threatened by the International Union for the Conservation of Nature.
Prospects for mangrove-restricted animals are bleak, because more than
two percent of mangrove forests are lost each year.More than 40
percent of a sample of amphibians, reptiles, mammals, and birds that
are restricted to mangrove ecosystems are globally threatened with
extinction, according to an assessment published in the July/August
issue of BioScience. The study, by David A. Luther of the University
of Maryland and Russell Greenberg of the Smithsonian Migratory Bird
Center, was based on an extensive literature search and expert
consultations. The conclusions emphasize the vulnerability of animals
that are dependent on a habitat rapidly being lost or degraded through
coastal development, overexploitation, pollution, and changes in sea
level and salinity.
Mangroves, which are salt-tolerant woody plants concentrated along
coastal margins, generally in warm regions, have long been known to
support many species of animals. Hundreds of vertebrates are sometimes
found in mangroves, but Luther and Greenberg concentrated on the 69
terrestrial vertebrate species and subspecies that seem restricted to
mangroves: 48 birds, 14 reptiles, 6 mammals, and 1 amphibian. These
include several species with striking adaptations, such as specialized
glands to excrete salt. The ground foragers among them feed primarily
on crabs, but many of the birds feed on insects. For unclear reasons,
mangrove-restricted species and subspecies are concentrated in Asia
and Australia.Between the early 1980s and 2001, between 19 and 35
percent of the world's mangrove forest area was lost. At this rate of
loss--about 2 percent each year--mangroves could be extinct in 100
years. Only 27 of the terrestrial vertebrates that are dependent on
mangroves have been assessed by the IUCN (International Union for the
Conservation of Nature), and 13 of those are classified as threatened
on the IUCN Red List, Luther and Greenberg report. They urge research
aimed at predicting how continuing changes to mangrove forests are
likely to affect the species found there: such information could guide
attempts to conserve these specialized ecosystems.

http://www.sciencedaily.com/releases/2009/07/090701082905.htm