By Russ Quinn
DTN Staff Reporter
KEARNEY, Neb. (DTN) -- How livestock grazing management affects wildlife habitat depends on many complex factors, including the type and location of grassland, the productivity of the range and even precipitation. Certain practices that might be positive for wildlife in one situation may not be so good in other grassland situations.
Balancing proper grazing management and preserving wildlife was one of the topics discussed at the 2018 Nebraska Grazing Conference held in Kearney, Nebraska, Aug. 6-8. There is no-one-size-fits-all practice for managing both grazing and wildlife, according to two presenters at the conference.
One of the speakers even titled his presentation "It Depends: Relationships between Wildlife and Livestock Grazing Management Vary Across Space and Time."
Lance McNew, an assistant professor of Wildlife Habitat Ecology at Montana State University, said local conditions mediate the effect of grazing management on wildlife.
While this may seem obvious, not all grazing practices are the same. The effects of a specific grazing system on wildlife populations is affected by rangeland productivity and precipitation. Precipitation is probably the most significant mediator of livestock grazing effects on wildlife, he said.
"Because of the interaction between livestock grazing management and the host of mediating factors vary over time and space, the 'silver bullet' of proper grazing management for all but the most geographically restricted species of wildlife is a myth," McNew said.
McNew points to the spatial extent of North America's prairie ecosystems. Rangeland management actions implemented within the tallgrass prairies of Kansas, Nebraska and Iowa will not produce similar results when applied to the northern mixed-grass prairies of North Dakota, South Dakota and eastern Montana.
"Even within a single prairie ecosystem, the annual variability in precipitation from one growing season to the next has been shown to significantly affect the range vegetation structure and composition. Without accounting for these difference, management actions many not improve range condition for wildlife habitat quality," he said.
Grassland-associated wildlife, especially grassland birds, have declined in the last 60 years as the number of acres of grassland have decreased across North America during this time, he said. These birds serve as literal "canaries in the coalmine" of prairie ecosystem health.
McNew said the interests of both grazing livestock producers and grassland wildlife overlap. The positive effect of grazing can lead to increased ecological functionality for wildlife and improved rangeland for grazing.
On the other end of the spectrum, improper livestock grazing can have a negative effect on wildlife, he said. This includes decreasing plant biodiversity and less biomass and residual cover, which will have a long-term effect on range condition.
MORE GRASSLAND RESEARCH
The issue of having grassland that supports both livestock grazing and wildlife has led to an uptick in research over the last 10 to 15 years, McNew said.
John Kraft, a research assistant with the Kansas Cooperative Fish and Wildlife Research Unit, said during his presentation that contemporary grazing management strategies, such as those with smaller pastures, shorter grazing periods and higher stocking densities, are growing in popularity to create uniform grazing. However, habitat heterogeneity (diversity) and biodiversity for wildlife is sacrificed, he said.
Kraft said a shift to more wildlife-friendly grazing management practices is one way to lessen the effects on wildlife. Among the most common practices would be patch-burn grazing.
A portion of the grassland is burned to attract grazing animals to graze in the burned regions, allowing previously burned patches to recover, he said. The patch-burn practice is designed to improve wildlife habitat quality by increasing the heterogeneity of the habitat structure.
Kraft said the lesser prairie chicken requires heterogeneous grassland habitats and are an ideal case study for evaluating the effects grazing strategies have on a species. He has examined how the lesser prairie chicken responsed to grazing disturbances and investigated how heterogeneity-based grazing strategies with lower stocking densities, larger pastures and shorter deferment periods affect the bird.
"The findings showed the lesser prairie-chicken hens used a large range of forage utilization values," he said.
"Breeding females did not place nests with pasture grazed at rates greater than 40% forage utilization, and most nests were placed on sites with forage utilization rates between zero percent and 20%," Kraft said.
Many of the results of the study produced predictable results. Regardless of the forage utilization, bird habitat increased as stocking densities decreased.
"In large pastures with relatively low-stocking densities, the lack of competition for high-quality forage by grazing livestock created variable grazing distribution. This distribution produces a desired habitat," Kraft said.
Despite the positive effects for grasslands, some grazers avoid burning grasslands. Fire is commonly not included in grazing management as a tool due to a culture of skepticism and fear, he said.
NEW MONTANA STUDY
McNew said a grazing management practice popular in Montana is rest-rotation grazing, where the land is grazed until seed heads are present and then the grass is rested for perhaps up to a year. This practice is not done for wildlife but for grassland health, which might have an effect on wildlife, he said.
McNew and his research team from Montana State recently completed a study on this type of grazing management and its effects on three grassland wildlife species - the sharp-tailed grouse, other grassland birds and mesocarnivores such as skunks, badgers and coyotes.
The results for the grouse showed there was no benefit for the birds in terms of nest survival, home range size or habitat selection and movement. McNew said there was even a case to be made where season-long grazing might even be better for the birds.
The grazing management, however, did produce a potentially positive increase for the songbird populations, which includes the vesper sparrow, grasshopper sparrow and the western meadowlark. In all cases, conservation-minded systems did increase the mesocarnivore population, he said.
"Grassland birds have shown species-specific or guild-specific responses to livestock grazing intensity," McNew said.
Russ Quinn can be reached at email@example.com
Follow him on Twitter @RussQuinnDTN
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