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Large
Animals Need Riparian Zones
Riparian zones are utilized by
wildlife as a sort of "natural highway". As roads and highways are
important to humans, forested riverbanks are important to mammals and birds as they
journey up and down the river during daily movements and seasonal migrations. These
areas may be important corridors for more than just wildlife migration, however: as plant
and animal habitats shrink or become fragmented, riparian zones may allow for the
preservation of genetic variability by maintaining connections with other populations of
their species, thus maintaining the gene pool within a species.
![Whitetail deer](pictures/deer2.jpg)
Whitetail deer along the Scioto River near Columbus,
Ohio;
Jay DeLong photo
Animals need a degree of
safety when visiting a site for drinking water. Riparian areas offer escape cover. |
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Throughout North America,
riparian areas provide wildlife benefits far out of proportion to their extent on the
landscape. Riparian zones offer an all-in-one package of the three critical
resources for wildlife: cover, food and water. These ecosystems provide year-round habitat
for many species of mammals, amphibians, reptiles, and resident birds, as well as breeding
sites, wintering areas, and stopover habitats for migratory birds. The U.S. Forest Service found 359 out of 414 wildlife
animals studied in upland forests in Oregon and Washington occupy riparian zones or
wetlands during all or part of their lives.
Other researchers found that between 63 and 74% (depending on the area) of the 341
species of vertebrate animals in British Columbia's forested ecosystems are associated
with riparian zones.![Bunnell, F.L., and L.A. Dupuis. 1993. Riparian Habitats in British Columbia: Their Nature and Role. Proceedings, Riparian Habitat Management and Research, Kamloops, BC. Fraser River Action Plan](pictures/source.jpg) |
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![Yellow-crowned night heron](pictures/BSheron.jpg)
Yellow-crowned night heron in Virginia wetland; Bruce
Stallsmith photo |
Riparian zones are elongated
"edges" (narrow zones of overlap between two different ecosystems) that attract
edge specialists as well as species that represent the surrounding ecosystems. The
edge is valuable to a greater diversity of wildlife species than either habitat alone. The importance of this "edge effect" for many bird and
mammal species is well documented. |
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If left undisturbed, stands of trees
provide habitat for cavity nesting birds such as woodpeckers, owls, wood duck, common
merganser, bufflehead, and common goldeneye. Other species such as some herons, osprey and
bald eagle preferentially nest in large trees close to a water source. ![Osprey](pictures/FLosprey.jpg)
Osprey in a dead tree in the Ocala National Forest,
Florida; Jay DeLong photo |
Riparian zones have a larger quantity of deciduous growth than upland forests, and these
are generally faster-growing plants than those in adjacent upland habitats. There is also
an increase in the variety of herbaceous species in wetter areas. For these reasons,
riparian zones are favored foraging habitats for many species including deer, elk, and
moose. |
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© Robert Carillio s_r_enterprises@hotmail.com and Jay DeLong thirdwind@att.net
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