BROOKINGS, S.D. — Spring rains are starting to give way to sunshine and warmer days across much of the state. This shift in the seasons has many producers looking forward to getting into the fields to start putting up hay. Anyone who has spent time cutting hay knows that hayland can be a magnet for wildlife in late spring and early summer. Hay fields are often considered an “ecological trap” for wildlife; that is, they appear to be high quality habitat for nesting or feeding due to tall, dense grass and legumes, but often lead to increased mortality once harvesting is under way. Mortality can be especially high for grassland nesting birds and young mammals that aren’t able to escape harvesting equipment. It is difficult to remove all of the negative effects to wildlife, but there are strategies that can mitigate some of these impacts.
Wildlife-Friendly Cutting Patterns
Wildlife mortality can be reduced by some simple changes to your harvesting practices. One simple way to increase wildlife survival is to cut hay from the center of a field toward the edges or from one side of the field to the other (Figure 1), rather than circling around towards the center. Often, animals will move out of the path of the swather into the remaining standing vegetation that has not been cut yet. If the hay is being cut in a spiral pattern towards the center of the field, the remaining grass patch becomes increasingly tighter. Animals may be hesitant to flee across the open, cut portion of the field, which can result in higher direct mortality from machinery; animals that do escape may be exposed to higher levels of predation because of the lack of cover. Conversely, if the hay is cut from the center to the edge or one side to the other, animals are able to move out of the path of the cutter towards the edge of the field and hopefully escape. If possible, cutting should progress towards an area of suitable cover to maximize this benefit (e.g. offer escape into standing vegetation vs. cutting towards a previously harvested field). Slowing down in areas where wildlife has been observed, especially hens with broods or does, can offer additional time for animals to get out of the path of machinery. Leaving unharvested strips can offer several benefits by providing escape cover and undisturbed habitat through the nesting season. Of course, this will reduce the hay yield off the field, but unharvested strips will help to catch more snow over the winter, and can be used as standing forage for winter grazing by livestock.
Figure 1. Hay cutting pattern to allow wildlife to escape machinery.
Credit: Pheasants Forever
Harvest Tools: Flushing Bars
Flushing bars are a tool that can limit mortality of birds nesting in hay fields. These are added in front of haying machinery (Figure 2) to flush hens off nests early enough that they will escape death. Although the nest will likely be destroyed, many bird species, including pheasants and ducks, will nest again if the bird survives. These may also be beneficial for young deer fawns, which typically lie motionless to hide from predators. A flushing bar can be designed to work with any type of hay cutting machinery, although some implements may present challenges for mounting. A flushing bar consists of a bar mounted parallel to and several feet in front of the cutting blade. Several short chains hang off the bar that drag along the ground to flush nesting birds. Obviously, care must be taken to ensure that the drag chains are well out of the way of any moving parts they could become entangled with.
A great way to improve wildlife survival in hay fields is to delay harvest when practical. By delaying harvest until the end of the primary nesting season, by August 1, the majority of nesting activity is complete, minimizing direct mortality to nesting birds. This is not always a desirable option for producers because of the increased maturity of the hay crop. If an operation has a strong wildlife focus, the benefits of increased game bird populations may outweigh the decrease in forage quality. Depending on the intended use of the hay, the decrease in quality may also be offset by an increase in total tonnage of hay by delaying harvest. If harvest cannot be deferred for the entire nesting season, delaying as much as possible will still provide benefits to nesting wildlife. Additionally, it is important to note that hay may not be cut from state roadside rights-of-way before June 15th in Tripp, Lyman and Gregory counties, or before July 10th in all East River counties (South Dakota Administrative Rule 70:04:06:06).
An ideal strategy for improving the benefits of hayland to wildlife is to shift from mechanical harvest to grazing, and stockpiling forage for a longer grazing season. Producers and wildlife alike can realize many benefits by shifting hay fields into the grazing rotation. Many of the benefits to the producer are beyond the scope of this article, but may include reduced capital investment and depreciation, reduced labor, reduced winter feed costs, and reduced nutrient export. From a habitat perspective, this shift removes much of the “ecological trap” from a hay field by removing the mortality from harvest and increasing nesting success. Additionally, the dung from livestock can result in large increases of insects, a crucial food source for chicks of many species. Grazing also has the added benefit of increasing the amount of grassland habitat available for wildlife year round. By incorporating a rotational grazing system, land managers can provide a mosaic of different plant communities and structures that will help ensure wildlife are able to meet their needs throughout the year. Making a transition to grazing certainly comes with challenges that must be considered. Producers should evaluate available fencing, water, and shelter, and identify which shortcomings can be addressed. Cost share programs are available to assist producers with installing infrastructure needed to make these types of management shifts. Other issues that may be more difficult to overcome include location and access; it may simply be impractical to move livestock to a distant parcel of land.
Hay production is an integral part of many South Dakota farms and ranches, but unfortunately can have negative effects on wildlife. These strategies can help to alleviate some of the negative aspects of haying and support wildlife production on working lands. Many resources are available to assist producers with adoption of wildlife-friendly haying practices, including SDSU Extension, SD Game Fish & Parks, US Fish and Wildlife Service, as well as non-profit conservation organizations such as Pheasants Forever and Ducks Unlimited.
— Jimmy Doyle, SDSU Extension
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