As the spring season unfolds, U.S. Fish & Wildlife Service (Service) fire personnel will be conducting prescribed burns on numerous waterfowl production areas throughout the Windom Wetland Management District. Spring is a time of renewal and Service staff utilizes prescribed fire in an attempt to mimic what was historically a natural ecological force – uncontrolled wildfire. Controlled burns rejuvenate prairie and wetland habitats by consuming accumulated dead vegetation, stimulating new growth, and controlling non-native plants. In turn, wildlife uses the improved habitat conditions for nesting, security (cover), and foraging.
The timing of prescribed fire is tied to the habitat management objectives for an individual waterfowl production area. Management objectives are most often biologically driven. Therefore the timing of a particular burn relates to the anticipated effects of the fire to the targeted vegetation within a burn unit. In many cases, the timing of a burn as it relates to the growth stage of a certain plant species can make the difference in the success or failure of a burn. Conducting a burn too early or late in the growth stage of a target plant species might actually result in an undesirable outcome.
As Service staff continues to learn how the timing of fire application affects certain plants, management strategies ultimately change. In recent years, more prescribed fire has been applied to a variety of habitats during late spring and summer, as compared to the early spring and fall timeframes that were used predominantly in the past. However, the timing of late spring and summer burns does often coincide with the nesting season of certain ground-nesting birds, which is certainly a consideration for Service personnel. Ultimately, wetland management districts are tasked with maintaining and improving habitats that support breeding migratory birds.
Application of prescribed fire is a habitat management tool and when timed properly, can serve to improve the vegetative species composition and structure of breeding bird habitats. When fire timing coincides with the nesting season, nest loss due to fire may ultimately occur. However, many bird species have evolved over time to deal with nest loss by attempting to re-nest one or more times during a given season. This includes the majority of upland nesting duck species, such as mallards and blue-winged teal.
When spring comes early and wetland conditions are ideal, a hen mallard might re-nest as many as six times in a single season, if necessary. The re-nesting factor, along with the fact that Service staff typically only burn a portion of the existing wildlife habitat in a given area (allowing nearby nesting habitat for displaced birds) is taken into consideration when planning prescribed fires. Although managers do generally try to avoid burning during the peak of the nesting season, the loss of some nests is accepted under the rationale that this is a short-term loss in an effort to provide a long-term gain, in the form of improved future nesting habitat. So the next time you see a prescribed fire burning across a portion of a waterfowl production area in mid to late May think ‘long-term’. It is important to understand that ground-nesting birds evolved with sporadic and patchy wildfires that blackened the landscape throughout nesting season.
Page 2 of 2 - The Service improves wildlife habitat through the careful use of controlled burns on more than 400,000 acres of National Wildlife Refuge System lands each year. The mission of the Service is working with others to conserve, protect, and enhance fish, wildlife, plants, and their habitats for the continuing benefit of the American people. The Service is both a leader and trusted partner in fish and wildlife conservation, known for its scientific excellence, stewardship of lands and natural resources, dedicated professionals, and commitment to public service. For more information on Service projects and the people who make them happen, visit www.fws.gov.