Wetlands: Boom and Bust

Founded with a mission of conserving waterfowl, the national wildlife refuge system today maintains the country's most productive inventory of wetland ecosystems. Just about every shape, size, and type of wetland is found on a refuge somewhere, and they're all in tip-top shape. Check out the new Audubon Guide series on national wildlife refuges. A few notable selections include the following:

Oxbow NWR (Harvard/Shirely/Ayer, Massachusetts) Water and wetlands are the major feature of this small, lush refuge not far from Boston. Boardwalks provide easy viewing of many beautiful wetland plants—blue flag iris, swamp milkweed, buttonbush. Several wetland types are here: shrub swamp, vernal pools, oxbow ponds, and marsh. Lots of neat frogs, turtles, and wetland-dependent birds, such as belted kingfisher and wood duck.

Horicon Marsh NWR (Mayville, Wisconsin) A modest drive from downtown Milwaukee, this is the largest cattail marsh in the nation (more than 21,000 acres) and among the largest on earth. Spring through fall, Horicon is a wildlife watcher's paradise. One of the Midwest's largest great blue heron rookeries is here, along with an immense nesting community of redhead ducks; fall waterfowl migration is a sight to behold.

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Lostwood NWR (Kenmare, North Dakota) A prairie pothole wonderland. Wetlands of every shape, size, and duration spangle this far-flung refuge. Birds, including many grassland species, are greatly varied, as are the many lovely wildflower species—blanketflower, blazingstar, milkvetch—that color the adjacent prairiescape.

Havasu NWR (Lake Havasu, AZ and Needles, CA) Prior to damming industrial-scale irrigation, the powerful Colorado River each spring and fall recharged a wealth of riverine wetlands along its floodplain. That natural cycle has been severely undercut, though a sizable remnant of this wetland type survives at Havasu. Water levels are controlled by refuge staff through a series of dikes and irrigation structures, which mimic the annual cycles of flooding and drying.

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