Abstract
Wetland loss in North America has been considerable and well documented, and the establishment of exotic species in remaining wetlands can further reduce their ability to support native flora and fauna. In the Chesapeake Bay and Great Lakes ecosystems, exotic mute swans (Cygnus olor) have been found to negatively impact wetlands through degradation of submerged aquatic vegetation (SAV) communities. Mute swan populations have expanded into many areas of mid-continental North America outside the Great Lakes ecosystem, but the environmental impact of these populations is not well known. Mid-continental wetlands in North America differ in physical characteristics (e.g., size, depth, and permanency) and aquatic vegetation species composition compared to wetlands in other areas where mute swans have been studied and, thus, may be more or less susceptible to degradation from swan herbivory. To investigate the impact of mute swan herbivory on SAV communities in mid-continent wetlands, we used exclosures to prevent swans from foraging in 2 wetland complexes in central Illinois. Above-ground biomass of vegetation did not differ between exclosures and controls; however, mean below-ground biomass was greater in exclosures (52.0 g/m2, SE = 6.0) than in controls (34.4 g/m2 SE = 4.0). Thus, although swan densities were lower in our study region compared to that of previous studies, we observed potentially detrimental impacts of swan herbivory on below-ground biomass of SAV. Our results indicate that both above-ground and below-ground impacts of herbivory should be monitored, and below-ground biomass may be most sensitive to swan foraging.
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References
Allin CC, Husband TP (2003) Mute swan impact on submerged aquatic vegetation and macroinvertebrates in a Rhode Island coastal pond. Northeastern Naturalist 10:305–318
Angeler DG, Alvarez-Cobelas M, Sanchez-Carillo S, Rodrigo MA (2001) Assessment of exotic fish impacts on water quality and zooplankton in a degraded semi-arid floodplain wetland. Aquatic Sciences 64:76–86
Atlantic Flyway Council (2003) Atlantic Flyway mute swan management plan: 2003–2013. Prepared by the Snow Goose, Brant, and Swan Committee
Badzinski SS, Ankney CD, Petrie SA (2006) Influence of migrant tundra swans (Cygnus columbianus) and Canada geese (Branta canadensis) on aquatic vegetation at Long Point, Lake Erie, Ontario. Hydrobiologia 567:195–211
Bailey M, Petrie SA, Badzinski SS (2008) Diet of mute swans in lower Great Lakes coastal marshes. Journal of Wildlife Management 72:726–732
Bellrose FC (1980) Ducks, geese, and swans of North America, 3rd edn. Stackpole, Harrisburg
Bellrose FC, Havera SP, Paveglio FL, Steffeck DW (1983) The fate of lakes in the Illinois River valley. Illinois Natural History Survey, Biological Notes 119. Champaign, Illinois
Benedict RJ, Hepp GR (2000) Wintering waterbird use of two aquatic plant habitats in a southern reservoir. Journal of Wildlife Management 64:269–278
Bowyer MW, Stafford JD, Yetter AP, Hine CS, Horath MM, Havera SP (2005) Moist-soil plant seed production for waterfowl at Chautauqua National Wildlife Refuge, Illinois. American Midland Naturalist 154:331–341
Dahl TE (1990) Wetlands losses in the United States, 1780s to 1980s. U.S. Department of the Interior, Fish and Wildlife Service, Washington
Devries JH, Brook RW, Howerter DW, Anderson MG (2008) Effects of spring body condition and age on reproduction in mallards (Anas platyrhyncos). Auk 125:618–628
Effler SW, Brooks CM, Whitehead K, Wagner B, Doerr SM, Perkins M, Seigfried CA, Walrath L, Canale RP (1996) Impact of zebra mussel invasion on river water quality. Water Environmental Research 68:205–214
Engel S (1995) Eurasian watermilfoil as a fishery management tool. Fisheries 20:20–25
Havera SP (1999) Waterfowl of Illinois: Status and management. Illinois Natural History Survey special publication 21. Champaign, Illinois
Hindman LJ, Harvey WF (2001) Status and management of mute swans in Maryland. In: Perry MC (ed) Mute swans and their Chesapeake Bay habitats: Proceedings of a symposium. USGS/BRD/ITR-2004-0005. U.S. Ecological Survey, Reston, Virginia
Holm TE (2002) Habitat use and activity patterns of mute swans at a molting and wintering site in Denmark. Waterbirds 25:183–191
Jonzen N, Nolet BA, Santamaría L, Svensson MGE (2002) Seasonal herbivory and mortality compensation in a swan-pondweed system. Ecological Modeling 147:209–219
Kiorboe T (1980) Distribution and production of submerged macrophytes in Tipper Grund (Ringkobing Fjord, Denmark), and the impact of waterfowl grazing. Journal of Applied Ecology 17:675–687
LaMontagne JM, Jackson LJ, Barclay RMR (2003) Compensatory growth responses of Potamogeton pectinatus to foraging by migrating trumpeter swans in spring stop over areas. Aquatic Botany 76:235–244
Ludyanskiy ML, McDonald D, MacNeill D (1993) Impact of the zebra mussel, a bivalve invader. BioScience 43:533–544
Mills EL, Leach JH, Carlton JT, Secor CL (1993) Exotic species in the Great Lakes: a history of biotic crises and anthropogenic introductions. Journal of Great Lakes Research 19:1–54
Mills EL, Strayer DL, Scheuerell MD, Carlton JT (1996) Exotic species in the Hudson River basin: a history of invasions and introductions. Estuaries and Coasts 19:814–823
Mississippi Flyway Council Technical Section (2006) Swan Committee Report. Winter 2006
Mulder CH, Ruess RW (1998) Effects of herbivory on arrowgrass: interactions between geese, neighboring plants, and abiotic factors. Ecological Monographs 68:275–293
Nolet BA (2004) Overcompensation and grazing optimization in a swan-pondweed system. Freshwater Biology 49:1391–1399
O’Hare MT, Stillman RA, Mcdonnell J, Wood LR (2007) Effects of mute swan grazing on a keystone macrophyte. Freshwater Biology 52:2463–2475
Perry MC, Osenton PC, Lhones EJR (2004) Food habits of mute swans in Chesapeake Bay. In: Perry MC (ed) Mute swans and their Chesapeake Bay habitats: Proceedings from a Symposium. USGS/BRD/ITR-2004-0005. U.S. Ecological Survey, Reston, Virginia
Person BB, Herzog MP, Ruess RW, Sedinger JS, Anthony RM, Babcock CA (2003) Feedback dynamics of grazing lawns: coupling vegetation change with animal growth. Oecologia 135:583–592
Petrie SA (2004) Review of the status of mute swans on the Canadian side of the lower Great Lakes. In: Perry MC (ed) Mute swans and their Chesapeake Bay habitats: Proceedings from a Symposium. USGS/BRD/ITR-2004-0005. U.S. Ecological Survey, Reston, Virginia
Petrie SA, Francis CM (2003) Rapid increase in the lower Great Lakes population of feral mute swans: a review and recommendation. Wildlife Society Bulletin 31:407–416
Reese JG (1975) Productivity and management of feral mute swans in Chesapeake Bay. Journal of Wildlife Management 39:280–286
Richards JH (1984) Root growth response to defoliation in two Agropyron bunchgrasses: field observations with an improved root periscope. Oecologia 64:21–25
Rodriguez-Villafane C, Becares E, Fernandez-Alaez M (2007) Waterfowl grazing effects on submerged macrophytes in a shallow Mediterranean lake. Aquatic Botany 86:25–29
Sakai AK, Allendorf FW, Holt JS, Lodge DM, Molofsky J, With KA, Baughman S, Cabin RJ, Cohen JE, Ellstrand NC, McCauley DE, O’Neil P, Parker IM, Thompson JN, Weller SG (2001) The population biology of invasive species. Annual Review of Ecological Systems 32:305–332
Smith CS, Barko JW (1990) Ecology of Eurasian water milfoil. Journal of Aquatic Plant Management 28:55–64
Stafford JD, Horath MM, Yetter AP, Smith RV, Hine CS (2010) Historical and contemporary characteristics and waterfowl use of Illinois River valley wetlands. Wetlands 30:565–576
Tatu KS, Anderson JT, Hindman LJ, Seidel G (2007) Mute swans impact on submerged aquatic vegetation in Chesapeake Bay. Journal of Wildlife Management 71:1431–1439
Tiner RW Jr (1984) Wetlands of the United States: current status and recent trends. National Wetlands Inventory, Washington
Willey CH, Halla BF (1972) Mute Swans of Rhode Island. Rhode Island Department of Natural Resources, Division of Fisheries and Wildlife. Pamphlet, no. 8, Providence, Rhode Island, USA
Acknowledgments
We thank the following IDNR employees who assisted in the design and implementation of this project: D. Holm, J. Buhnerkempe, R. Marshalla, B. Douglass, and S. Weimer. A. Janke created the figure. Funding was through the Federal Aid in Wildlife Restoration program administered through the IDNR (project W-153-R). S. Badzinski provided helpful comments on a previous draft of this manuscript, and A. Janke helped create figures. Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government.
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Stafford, J.D., Eichholz, M.W. & Phillips, A.C. Impacts of Mute Swans (Cygnus olor) on Submerged Aquatic Vegetation in Illinois River Valley Backwaters. Wetlands 32, 851–857 (2012). https://doi.org/10.1007/s13157-012-0316-6
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DOI: https://doi.org/10.1007/s13157-012-0316-6