Habitat Description

Habitat Crosswalk


Hay, especially late-harvest hay, provides an important surrogate grassland habitat in Wisconsin. Hay can be derived from a variety of cover crops, including warm-season grasses (i.e., wild hay), cool-season grasses (i.e., tame hay), and various legumes and forbs (USDA 2002). Wild hay typically contains a high proportion of native warm-season grasses such as big blue-stem, yellow Indian grass, and switchgrass but also can include wetland plants such as sedges, prairie cord grass, bluejoint grass, and manna grasses. Tame hay is composed of non-native cool-season grasses such as timothy, smooth brome, orchard grass, Kentucky bluegrass, and reed canary grass. Legume hay has a high proportion of legumes such as alfalfa, red clover, and white clover and low grass cover.

Wild hay can provide greater structural diversity and cover availability than other hay types (Ryan 1986, Undersander et al. 2002). It also produces 70% of its biomass after 1 June and thus is not harvested during the peak nesting season of most birds (Giuliano and Daves 2002). In contrast, tame hay and legume hay mature in late spring and thus are harvested earlier and more frequently than wild hay (Giuliano and Daves 2002, Undersander et al. 2002). Intensive hayfield management such as this is incompatible with most bird nesting cycles and has been implicated in the decline of grassland bird populations (see Overall Importance of Habitat for Birds). When applied properly, however, haying can be an effective management tool for maintaining an open grassland system.

Historical and Present-day Context and Distribution

During the nineteenth century, diverse prairie communities in Wisconsin were largely eliminated in favor of small grains, grass hay, alfalfa, pastures, and orchards. Although these changes destroyed or significantly altered most native grasslands, the landscape remained largely rural with small farmsteads interspersed with idled or undeveloped lands. Many birds adapted to these changes and used the diversified, small-scale farms as surrogate grassland habitats (Warner 1994). By the mid-twentieth century, however, farming systems became more specialized and fewer areas were left uncultivated. Non-crop habitats such as grassy corridors, field borders, idled lands, and farm ponds were eliminated in favor of more corn and soybeans (Warner 1994, Best et al. 1995, Sample et al. 2003, WDNR 2005). Synthetic fertilizers enabled crops to be grown at higher densities and negated the need for diversified crop rotations. The development of pesticides and modern farm machinery also reduced the amount of crop diversity per individual farm (Chamberlain et al. 2000). As a result, many farms now contain monocultures of corn and soybeans instead of diversified crops. Over the last 50 years, combined pasture and hayfield acreage has declined by more than 50% in the Midwest and is now at its lowest level in more than 100 years (Herkert et al. 1996). According to the 2002 Census of Agriculture, hay constituted only 23% of the harvested cropland in Wisconsin (USDA 2002). The type of hay crop also has changed. Many farms now plant early maturing hay crops such as legume and cool-season grasses rather than late-maturing warm-season grasses. As of 2002, combined legume hay (alfalfa) and tame hay covered more than 800,000 hectares in Wisconsin compared to only 18,700 hectares of wild hay (USDA 2002).

Natural Disturbances and Threats

Mowing operations drastically alter the structure of hay crops and cause significant disturbance to wildlife using hayfields (Herkert et al. 1996, Koford and Best 1996). However, the amount of disturbance depends on the type of hay crop. Wild hay crops mature late in the growing season and thus provide undisturbed cover through early summer. Tame hay and legume hay mature earlier in the season and thus require an earlier harvest than wild hay. Earlier harvest dates also enable multiple plantings within a single season, which increases the amount of disturbance. These changes have been detrimental to grassland bird populations and have caused many hayfields to become ecological traps (see Overall Importance of Habitat for Birds). In most cases, harvests cannot be delayed without severe economic losses to the farmer (Ryan 1986, Best et al. 1995, Sample and Mossman 1997, Nocera et al. 2005, Perlut et al. 2006).

A significant threat to hayfields is the intensification of agricultural practices. Confinement dairy farming has led to a reduction in use of hay and an increased reliance on grain feed. As a result, large acreages of hayfields are being converted to intensively-managed row crops that have low wildlife value (Sample and Mossman 1997). Renewed interest in corn ethanol and other market factors have led to high corn prices, creating additional pressure on remaining hay, pasture, and CRP acres (Murray and Best 2003, Roth et al. 2005, Bies 2006). Urban sprawl is another significant threat. As housing developments replace farmland throughout the state, hayfields are either destroyed or isolated from other surrogate grassland habitats.

Related WBCI Habitats: Idle Warm-season Grasses and Forbs, Idle Cool-season Grasses and Forbs, Pastures.

Overall Importance of Habitat for Birds

Hayfields are a dominant grassland type in the state and thus are important for maintaining grassland bird populations. Ring-necked Pheasant, Sedge Wren, and Henslow’s Sparrow can be abundant in wild hay prior to harvest whereas Savannah Sparrow, Dickcissel, Bobolink, and Red-winged Blackbird are highly attracted to legume-dominated hayfields (Best et al. 1995, Sample and Mossman 1997, Ribic and Sample 2001). However, conventional hayfield management poses a significant threat to grassland birds because it often occurs during a critical time of the nesting cycle (Ryan 1986, Perlut et al. 2006). The first harvest of legume and tame hay can occur between late May and late-June, which is when most birds are either incubating or feeding young nestlings. Harvest machinery can crush eggs and nestlings, cause adults to abandon nests, and/or expose intact nests to increased predation. Young fledglings also are vulnerable when they first depart the nest because they are not yet able to fly (Perlut et al. 2006). In some cases, harvesting hay during the peak nesting period (i.e., late May to early July) can cause complete reproductive failure. Although sparse-cover specialists such as Killdeer, Upland Sandpiper, Horned Lark, Vesper Sparrow, and Western Meadowlark may recolonize recently-cut fields, they also may fail to reproduce successfully because of second harvests (Best et al. 1995, Sample and Mossman 1997). Multiple harvests within a single season have become common as farmers exploit the peak in nutritive value and productivity of the tame and legume hay. Shorter time periods between haying events further diminishes a species’ chance to successfully fledge young (Perlut et al. 2006).

Farmers interested in grassland bird conservation should attempt to cut early-hayed fields as early as possible and delay the second cut until after 15 July to improve nesting productivity (Dale et al. 1997, Sample and Mossman 1997, Giuliano and Daves 2002). Alternately, using native warm-season grasses (i.e., wild hay) in place of early-harvest crops will benefit nesting birds. Wild hay is typically harvested well after the peak nesting period of most grassland birds and thus provides important undisturbed cover within intensively managed agricultural areas. Giuliano and Daves (2002) found grassland birds nesting in agricultural areas of Pennsylvania had greater abundance, richness, and reproductive success in wild hay than tame hay. Wild hay provides a refuge for second nest attempts and dispersing fledglings, especially when located adjacent to disturbed areas. It also may provide more residual cover than other hay types, which benefits priority species such as Henslow’s Sparrow and Sedge Wren (Sample and Mossman 1997, Giuliano and Daves 2002).

Priority Birds

Species Status Habitat and/or Special Habitat Features
Mallard b If appropriate open water for breeding pairs and broods is available nearby.
Blue-winged Teal b If appropriate open water for breeding pairs and broods is available nearby.
Greater Prairie-Chicken b, w May occur in grass hayfields surrounding core protected areas in central Wisconsin.
Northern Bobwhite b, w Requires brushy areas adjacent to hayfields.
Northern Harrier b, m May occur in grass hayfields embedded within a large, grassland-dominated area.
Upland Sandpiper B, M May occur in hayfields embedded within a large, grassland-dominated area.
Barn Owl f Very rare resident in southern and central Wisconsin.
Short-eared Owl b, m, w May occur in grass hayfields embedded within a large, grassland-dominated area.
Sedge Wren b, m Prefers dense herbaceous cover and a substantial component of residual vegetation.
Common Yellowthroat b, m Prefers dense herbaceous cover.
Vesper Sparrow b, m Prefers the short, sparse cover of recently harvested hayfields.
Grasshopper Sparrow B, M Prefers relatively short, patchy vegetation.
Henslow’s Sparrow b, m Prefers tall, dense herbaceous cover that is grass-dominated with a substantial component of residual vegetation.
Dickcissel b, m Prefers sites with a thick-stemmed forb component.
Bobolink B, M  
Eastern Meadowlark B, M  
Western Meadowlark B, M  


Management Recommendations

Landscape-level Recommendations

  1. Support state and federal programs that manage, enhance, or restore grassland habitats on private lands. Develop cooperative agreements with private landowners to prevent habitat fragmentation and conversion in areas critical for grassland bird conservation.
  2. Partner with the agricultural community to ensure rural working landscapes with high amounts of open space suitable for birds and other wildlife.
  3. Determine what scale of landscape management is possible in an area: medium (400-2,000 hectares) or large (>4,000 hectares). Consider developing a grassland Bird Conservation Area in appropriate landscapes (see Fitzgerald and Pashley 2000).
  4. Prioritize land acquisitions that permanently protect important grassland projects within key ecological landscapes. These lands form the nucleus of protected grasslands within a matrix of partner-private lands projects.
  5. Offer incentive payments to delay harvest on private lands where priority grassland birds are nesting.  

Site-level Recommendations

  1. Identify excess fields, fields that may not be critical for early hay mowing, and fields that are usually too wet for early mowing to form the base of a grassland conservation effort on individual farms. Preferably these areas are adjacent to one another to create a single, large refuge area (Undersander et al. 2000, Ochterski 2006).
  2. Locate idle nesting cover (i.e., old fields, set-aside lands, strip cover) adjacent to hayfields to provide alternate habitat for species that renest after mowing-induced failure of first nest attempts (Sample and Mossman 1997, NRCS 1999).
  3. Seed fields with later-maturing grasses and legumes so hay mowing can be delayed until after fledging - approximately 15 July (Ochterski 2006).
  4. Avoid planting dense monocultures of cool- or warm-season grasses. Reduce grass seeding rates by up to 50% to reduce vegetation density and to encourage forbs (Sample and Mossman 1997).
  5. Include enough forb seeds in mixes to result in at least 10% forb cover. In most cases, 10,000-20,000 forb seeds per acre should produce a noticeable forb component (Sample and Mossman 1997).
  6. Reduce the use of pesticides and inorganic fertilizers through Integrated Pest Management practices and by rotating crops that provide nitrogen such as alfalfa, clover, soybeans with crops that use nitrogen such as corn and wheat (UWEX 1998, NRCS 1999).
  7. Mow hayfield from the field center outward to provide cover that allows fledgling birds to escape to the edge of the field. Flushing bars should be mounted on harvesting equipment to minimize bird mortality during mowing operations (NRCS 1999, Ochterski 2006).
  8. Avoid mowing during the night when nesting and roosting birds are less likely to flush (NRCS 1999).
  9. Remove linear woody features such as hedgerows and woody fencelines as well as woodlots to improve site suitability for obligate grassland birds. Low density, scattered shrubs are acceptable and even required by some grassland birds such as Willow Flycatcher, Bell’s Vireo, and Brown Thrasher (Sample et al. 2003, WDNR 2005, Kost et al. 2007). 

Ecological Opportunities

Ecological Landscape Opportunity Management Recommendations
Central Lake Michigan Coastal Important All
Northern Lake Michigan Coastal Important All
Southeast Glacial Plains Important All
Southern Lake Michigan Coastal Important All
Southwest Savanna Important All
Western Coulee and Ridges Important All
Western Prairie Important All
Central Sand Hills Present All
Central Sand Plains Present All
Forest Transition Present All
North Central Forest Present All
Northeast Sands Present All
Northern Highlands Present All
Northwest Lowlands Present All
Northwest Sands Present All
Superior Coastal Plain Present All

Research Needs


Key Sites

Late-harvest hayfields occurring on private lands can complement adjacent public lands by increasing overall grassland heterogeneity and size. Listed below are native grassland sites that might benefit from nearby late-harvest hay habitats.

Key Partners

Funding Sources

Information Sources


Contact Information

Kreitinger, K., Y. Steele and A. Paulios, editors. 2013.
The Wisconsin All-bird Conservation Plan, Version 2.0. Wisconsin Bird Conservation Initiative.
Wisconsin Department of Natural Resources. Madison, WI.

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