SOUTHEAST - 4
HORICON MARSH WETLAND TYPES Jack Bartholmai Marsh, sedge meadow, shrub carr
ECOLOGY & SIGNIFICANCE is composed primarily of emergent marsh species, particularly cattails. The site is primarily deep-water Horicon Marsh is the largest freshwater cattail marsh marsh although other wetland types occur. in the United States, boasting more than 32,000 • wetland acres. The site has garnered many superlatives This Wetland Gem is a mecca for wildlife with 300 DODGE COUNTY and recognitions; it is designated as a Wetland of species of birds, snapping turtle, garter snake, white- International Importance and as both a Globally and tailed deer, red fox, river otter, muskrat and many other State Important Bird Area. Horicon Marsh is a shallow, animal species. Horicon Marsh is best known for hosting
- peat-filled lake bed that was created by glacial scouring tremendous numbers of waterfowl during migration, and impounding of the basin by a recessional moraine including more than 250,000 Canada geese and 100,000 at the end of the last ice age. The northern two-thirds of ducks in the fall. Significant numbers of shorebirds the marsh is managed as a National Wildlife Refuge and also use Horicon as a migratory stopover during draw the southern third is managed as a State Wildlife Area. downs and low water levels. The site supports significant The site provides stopover habitat for huge numbers of breeding populations of waterbirds such as least bittern, migratory waterfowl and supports a number of rare and American bittern, black-crowned night-heron, American endangered species. white pelican and great blue heron. Horicon also hosts FLORA & FAUNA the largest breeding population of redhead duck east of the Mississippi River. Other rare birds include black tern, The marsh has a long history of human alteration and Forster’s tern, king rail and great egret. impacts including ditching, draining and muck farming that occurred before the lands were bought and restored THREATS by public agencies. Restoration has had outstanding Polluted runoff from agricultural practices on surrounding results, but the legacy of these historical alterations still lands degrades water quality and accelerates sedimentation. influences current marsh habitats. An extensive system Increasing watershed development and invasive species of dikes and ditches are used to manage the wetlands also threaten wetland habitat quality. Proximity to both via water level manipulations in order to counteract the Milwaukee and Madison means large numbers of visitors; remaining ditches and maximize the value of wetlands for waterfowl and other wildlife. Vegetation at Horicon recreational use may also impact site wetlands.
ACCESS
HORICON MARSH Owners: USFWS, WDNR Property of Inter Recognitions & Designations: Ramsar Convention Wetland Conservancy Globally Importantnational Importance, American Bird Conservancy WI Land Legacy Place, The Nature Priority Area, Bird Conservation Initiative Important Bird Conservation WI Bird Area, Wisconsin Unit of the Ice Age National Scientific Reserve Area, of This site offers a variety of recreational opportunities, including the new Horicon Funding for this project provided by The McKnight Foundation, Marsh International Education Center. which seeks to improve the For details, visit www.horiconmarsh.org, quality of life for present and future generations through the WDNR Horicon Marsh State Wildlife grantmaking, coalition-building Area website: www.dnr.state.wi.us/org/ and encouragement of strategic policy reform. land/wildlife/wildlife_areas/horicon, and the USFWS National Wildlife Refuge website: www.fws.gov/midwest/horicon.
Sources: Horicon National Wildlife Refuge (USFWS) Horicon Marsh State Wildlife Area (WDNR) wisconsinwetlands.org Wisconsin Land Legacy Report (WDNR) The Prairie-Forest Border: An Ecoregional Plan (TNC) American white pelicans — Jack Bartholmai Wisconsin Important Bird Areas (WBCI)