Geoscience Reference
In-Depth Information
7
Wetland wildlife
tal agencies. Even though other wetland func-
tions are equally important, it is wildlife that
most attracts public interest and political support
for conserving wetland environments. Typically
it is animals near the top of the food chain
that garner the most attention, namely birds,
mammals and large reptiles (Fig. 7-2). Less
attention is given to smaller and inconspicuous
animals, although colorful butterl ies are excep-
tions (see Color Plate 6-14). Nevertheless,
smaller vertebrates and invertebrates, particu-
larly insects, are present in great abundance and
diversity within wetlands.
Wetland animals must deal with low oxygen
levels and other constraints just as the plants
must. Many animals, unlike plants, can move,
which gives them more ways to cope with
wetland environments. They have adapted
several morphological and behavioral means to
handle anaerobic conditions (Table 7-1). Many
other animal adaptations are concerned with
feeding, breeding, and raising young in order to
exploit the rich potential and relative safety of
wetlands (Dugan 2005). The method of feeding
and means of locomotion are usually most
instructive for understanding these adaptations.
In other words, mouths and jaws indicate how
and what an animal eats, and limbs are special-
ized for swimming, digging, climbing, running,
l ying, and other means of moving. In the fol-
lowing discussion, representative invertebrates
and vertebrates are considered for selected
groups of wetland animals.
Chinese characters for Mandarin duck
(
Aix galericulata
) courtesy of L. Huang.
7.1 Introduction
Wetlands are some of the most productive eco-
systems in the world and are home to a rich
variety of invertebrate and vertebrate animals
ranging from delicate damsell ies (suborder
Zygoptera) to the Bengal tiger (
Panthera tigris
).
As with hydrophytes, many of these animals
have special adaptations for living exclusively in
wetland environments; others may visit wet-
lands frequently or occasionally, but are not
dependent on wetlands for their survival. Wild-
life is the most visible and understandable
aspect of wetlands for most people. We hunt,
i sh, and harvest all manner of wildlife
-
diverse
i sh and shelli sh, ducks and geese, fur-bearing
mammals, etc. Wetlands are particularly popular
for bird watching (Fig. 7-1) as well as observing
all other types of common and rare animals.
Protecting wildlife has been the primary
inspiration for preserving and restoring wetland
habitats worldwide, as demonstrated by Ramsar,
Ducks Unlimited, the Nature Conservancy, and
many other organizations as well as governmen-
