Prescribed Burns and Wildlife Concerns

Prescribed fire is one of the most useful tools for land management, habitat improvement, and ecosystem restoration. With controlled burns, we can prepare new prairie sites for seeding, reduce invasive species pressure, remove woody species encroachment, and recycle nutrients into prairies and woodlands. In Minnesota (and across many parts of the US), the ideal time for conducting a prescribed burn is April-May. However, as this is also peak nesting season for many game and non-game bird species, there are often concerns that fire will destroy nests and decrease wildlife populations. 

Prescribed fire is commonly used to improve wildlife habitat, so how dangerous is it for nesting birds and other wildlife species?

This question has been studied throughout Minnesota, as well as in the southern states where prescribed fire in April and May runs through deer and wild turkey nesting habitat. Studies have found that not only does fire have minimal effect on nest mortality, but many of these wildlife species actually prefer recently burned areas. A study conducted by the Wildlife Society found that deer, birds, and predators inhabited recently burned areas more frequently than non-burned areas in the first 6-months to 2 years following controlled fire (Main & Richardson, 1973). Similarly, a study of non-game bird species in oak savannas and woodlands in Minnesota found that non-game bird populations increased with increased fire frequency (Au et al., n.d.). Similar findings were made for mixed-grass prairies (Johnson, n.d.). 

So what about nesting species and nest mortality? Casual observations from prescribed fire technicians in many areas describe a lack of mortality among any wildlife species. Indeed, in many places where prescribed burn cycles are frequent, wildlife species are observed calmly moving around the fire, seemingly unperturbed (Main & Richardson, 1973). However, casual observations are not a complete record of data, so one research group measured specific mortality of wild turkey nests in areas burned with prescribed fire. They studied 30 nests, and found that only 1 of the 30 nests failed because of prescribed fire. Compared to 16 of 30 which failed from natural predation, the introduction of fire to the habitat had relatively little impact on nesting (Kilburg et al., 2014). Furthermore, many ground nesting game birds such as turkeys and pheasants will re-nest if their first nest fails. Therefore, the overall effect of prescribed fire on game and wildlife populations is minimal at best. The benefits of the habitat improvement outweigh the potential for a handful of lost nests.

It’s important to remember that many of the ecosystems in Minnesota are naturally fire-prone ecosystems. Tallgrass and mixed grass prairies, oak savannas, oak woodlands, pine forests, and even wetlands all have historic fire cycles. For prairies and savannahs, fire historically occurred on short cycles of every 20 years or less. For forests, these cycles may be as long as 100 or more years. However, the fact remains that all our natural ecosystems evolved in the presence of fire. Many native plant and animal species are adapted to surviving fire—which is one reason it is such a good tool for improving native habitats. Without prescribed fire, our ability to restore and conserve biologically diverse and healthy habitats would be severely diminished.

References

Au, Leakhena, Andersen, D. E., Davis, & Mark. (n.d.). Patterns in bird community structure related to restoration of Minnesota dry oak savannas and across a prairie to oak woodland ecological gradient. https://doi.org/10.3375/0885

Johnson, D. H. (n.d.). 8. Effects of Fire on Bird Populations in Mixed-Grass Prairie.

Kilburg, E. L., Moorman, C. E., Deperno, C. S., Cobb, D., & Harper, C. A. (2014). Wild turkey nest survival and nest-site selection in the presence of growing-season prescribed fire. Journal of Wildlife Management, 78(6), 1033–1039. https://doi.org/10.1002/jwmg.751

Main, M. B., & Richardson, L. W. (1973). Response of Wildlife to Prescribed Fire in Southwest Florida Pine Flatwoods. In Bulletin (Vol. 30, Issue 1). https://about.jstor.org/terms