The two predominate threats to this area include urbanization and the spread or intensification of agriculture. Along with these changes in the landscape come secondary impacts such as the loss of wetlands, increased sediment and run-off, introduction of pests and invasive species. Some of the private lands within this area are currently being managed under a Conservation Reserve Program agreement. Changes in the 2012 Farm Bill and the overall reduction of CRP lands within the next 5 years make the management of these lands uncertain for the future. The reduction of CRP lands will likely result in increased agriculture as well as potential increases in development and deforestation on private lands.
The Prairie Coteau Complex IBA focuses on prairie, grassland and marsh birds because the availability of quality habitats for these species are becoming less common in the southwest region of the state. This IBA hosts a number of species of conservation concern including: Henslow's Sparrow, Burrowing Owl and Chestnut-collared Longspur (endangered); Horned Grebe, Wilson's Phalarope and Loggerhead Shrike (threatened); and Marbled Godwit, Franklin's Gull, Forster's Tern, Short-eared Owl, and Nelson's Sparrow (species of special concern). In total, 251 species have been observed here including 71 Species of Greatest Conservation Need. Likewise, this IBA supports assemblages of species that represent high quality, rare habitat types such as sedge wetlands and native prairie.
MN-1e. Species Diversity
IBA criteria for species diversity calls for the site to support at least 12 species of shorebirds; at least 23 have been observed within the Prairie Coteau Complex:
MN-2a. Endangered, threatened or species of special concern
Eight federally listed species have been recorded within this IBA complex:
Data for the Forster?s Tern and Burrowing Owl are considered in a historical perspective as they were both documented prior to 1990. The Forster?s tern was recorded in the Natural Heritage Database (last record 1976). Likewise, the most recent records for Burrowing Owls were collected during research that was conducted from 1985-1987 (M. Martell 1990, Martell et. al. 2001).
MN-2b. Species of conservation concern
Thirty-nine Minnesota species of conservation concern have been observed within the Prairie Coteau IBA (Appendix 1). Three species that have been seen reliably and have consistent numbers are the Upland Sandpiper (79 in 2009), Dickcissel (69 in 2006), and Bobolink (49 in 2006, and 78 in 2009).
MN-3. Rare, threatened, or unique habitat assemblages
The Prairie Coteau IBA has 7 of the 9 species representative of sedge wetland (rich fen, poor fen, wet meadow) habitat type:
Le Conte's Sparrow
This IBA has 25 of the 28 species representative for native prairie (dry, mesic, wet prairie):
Le Conte's Sparrow
The major threat to this area, which is directly related to most of the threats on the list, is the expiration of Conservation Reserve Program lands in the 2012 Farm Bill. This introduces uncertainty as to how these lands will be managed, with the likely reality being that private lands once managed for wildlife will return to agriculture, biomass production and grazed lands. With the conversion of prairie and wetlands back into agriculture comes the drainage of marshes, increased use of pesticides and potential for over grazing, all of which negatively impact the remaining remnants of native prairie and wetland habitats.
This region was historically covered by native prairie with patches of interspersed wetlands, predominately shaped by climate, grazing and fire. Since the early 1900s the native tallgrass prairie has been converted predominately into agricultural fields. Fire suppression practices have also altered the landscape by allowing prairie succession and reducing the diversity of native grasses that once thrived here. Likewise, long duration, high intensity grazing regimes have impacted the prairie, creating grasslands that are less diverse and more susceptible to erosion and weed infestation.
Wind development is another growing industry in this area that has the potential to impact grassland birds and transform the landscape.