- October 27, 2016
Not mowing is a wonderful way to mindfully encourage wildlife; but, that isn’t always an option. Some need to harvest hay, prep fields for planting, or maintain a meadow susceptible to succession by woody plants. When it is time to mow, we want you to know there are simple strategies to consider to minimize negative impacts on wildlife.
Ensuring that wildlife can use farms and other open grassy areas as habitat is vital in the United States where over 50% of the land is used for some form of farm production. In many areas, the answer is simply one of timing.
Mowing is devastating for many species of animals, but it is most devastating for those, like grassland songbirds, who are laying eggs and raising young in fields that are cut before offspring fledge. The dates for these activities vary by region and species of birds. Vermont researchers found that Bobolinks (Dolichonyx oryzivorus), pictured above, and Savannah Sparrows, (Passerculus sandwichensis), are two species most at risk of population declines due to early mowing practices by farmers in hay fields. In this region, waiting until the first of August, or even better, the end of August ensures higher survival rates for the offspring of these species.
The USDA created this guide, pictured above, based on the primary nesting season of birds that can act as a guide to landowners across the United States who are interested in protecting habitat for nesting grassland birds. Most regions recommend delaying mowing until after the first of August, but for some areas the danger-zone persists until the middle of September.
Several people have anecdotally reported that they have success saving nests by practicing the art of close observation of their fields. By walking their fields and monitoring wildlife in the month leading up to their mow-date they are able to locate some nests, mark them, and avoid them when they get on the tractor to cut the hay. This mindful approach to mowing is a great way not only to preserve nests, but also to engage with nature. To formalize this monitoring, you might consider recording your observations in eBird and NestWatch–projects designed to help you track and improve your powers of observation.
Learn how to find nests: Watch and listen first
Before you set off searching for nests, spend some time quietly observing the birds around you; they will often give you important clues about where their nests are located. Not only will listening first tell you what species’ nests may be present, but because male birds sing to mark the boundaries of their territories they will also tell you generally where to search. Watch individual males as they move from point to point and sing, and mark their locations on a map or record the area that you will search. Together, these points will outline the approximate territory surrounding a nest site. Within this territory, look for a female calling to her mate. Watch her from a distance through binoculars; many females will call on their way to the nest or even while on the nest (e.g., grosbeaks). Learn More…
New technologies may eventually help solve some of these challenges for farmers. Sensors that can detect nests in fields, like this nest of Savannah Sparrows buried in the tall grass, may eventually be available to farmers allowing them to route around areas where known nests are present.open_in_new
Birds, of course, aren’t the only wildlife you will find hunkered down in a field. With a little searching in the image above you’ll find another common occupant of grasslands during breeding season. Harvest delay helps save a myriad of wildlife.
Wildlife-friendly mowing at home
The video above recommends letting your lawn grow longer than average, perhaps encouraging patches of flowers to bloom for bees and other pollinators. If you have a small lawn, consider checking your grass before mowing for small creatures that might be using the habitat area. When mowing, go slowly, starting from the center of your lawn and working out towards the edges. This provides the opportunity for wildlife to respond to the disturbance and flee to safety outwards, rather than slowly driving them inwards with no escape. Finally, instead of using the mower right up against edges, where wildlife frequently hide, use hand shears in these sections to minimize harming smaller animals like frogs, toads, snakes, spiders, and small mammals.
Using a push mower instead of an electric or gas powered mower is likely to benefit wildlife simply because you are moving slower. Aside from helping wildlife, there are other environmental benefits including the elimination of oil, gasoline, and VOC (volatile organic compounds)open_in_new emissions, decreased noise pollution, and reduced dependence on fossil fuels.
Delaying a harvest, however, may pose challenges for some farmers who need to maximize their productivity by doing multiple hay harvests or those that need to turn over fields in the middle of the season. When you can’t wait, there are other options for “wildlife-friendly mowing.” For instance, you can create prairie strips, or areas that are left unmowed near agricultural fields, as refuges for wildlife that might otherwise find themselves in the mow-zone.open_in_new Prairie strips can be left around the borders of crop or hay fields or they can be used in between rows of areas that are harvested. They become hiding places for wildlife while heavy machinery and people work in the crops, and are resources for pollinators as well.
The spaces devoted to “prairie strips” can be rotated seasonally, annually or semi-annually depending on the needs of the farmers. The most important management choice is that they are left undisturbed during nesting season. Bush hogging these strips once in the fall will allow farmers to avoid succession of woody plants and shrubs and minimize the encroachment of invasive species in fields. Bush hogging is done using a rotary mower that hooks onto a tractor and cuts grass at three inches or higher using a dull blade.
Another wildlife-friendly mowing strategy is to mow from the center out. The tractor in the image above is doing the exact opposite–mowing inwards–driving any wildlife in that field inwards into an increasingly tighter space where they continue to be in the path of the mower blades.
Large properties with open meadows and farms play an important ecological role as habitat. Exploring diverse solutions to helping our farmers maximize their productivity while also protecting wildlife is an important and on-going problem to solve.
Wildlife-friendly Mowing Tips
Add it to your Map
Tell us about your mowing practices.
Begin by selecting the grass habitat(s) on your map. You will know you’ve selected this habitat as it will be outlined in a yellow color.
Then, click on the green info button and complete the characteristics for your mowing practices. This information will then update your Planning Tool actions and goals for your map.