- November 2, 2016
To mow or not to mow? That is a good question. On a warm spring or summer morning, walk by a field or a wild-growing roadside shoulder. Count the sounds you hear and the signs of life you witness. Whether or not you can hear or see them, thousands of interactions are taking place among the flowers and grasses. There are pockets of green space across our working landscapes that are heavily managed–mowed and irrigated–that don’t necessarily have to be. Read on to get an overview of how not mowing can change the story for wildlife in some of the least expected places.
An unmowed area is habitat for a bouquet of life. The roots of the plants are engaged in a vibrant microbial dance in their subterranean substrate where millions of organisms are doing their busy work of decompositional nutrient recycling. Small insects such as ants, aphids, beetles, and spiders busily scurry up the plant stalks. Preying upon those small insects are a myriad of predators–larger insects, birds, frogs, lizards, and small mammals. Those predators are themselves prey to even larger animals, like raptors and large mammals. All these complex interactions can be found in one small patch of unmowed space.
Roadside, Medians, Sidewalks
Unmowed areas are becoming more popular on both private and public lands. Some municipalities are choosing to encourage grass or wildflower strips along roadsides, down city streets, and adjacent to sidewalks. Much of this effort is a reaction to the evidence of decreasing pollinator populations weakened by disease, pesticide exposure, and habitat loss.open_in_new
The United States, alone, has four million miles of highways. While these have traditionally been planted and mowed as lawn, there is a budding movement by some states (Washington, Florida, Iowa, and Virginia are standouts) to rethink how these expansive spaces are used.
Research has shown that reduced mowing does not cause more wildlife car collisionsopen_in_new but it does save moneyopen_in_new, increase the aesthetic quality of roadways, and provide habitat for bees, birds, and butterflies. A study in Florida tested three mowing regimes–no mowing, mowing every six weeks, and mowing every three weeks–they found that the more frequent the mowing, the reduced number of floral and butterfly species, while no-mowing yielded the largest species richness.open_in_new
In Saltdean, in the United Kingdom, half of the area of a public park was left to grow into a field of wildflowers and was mowed only once in the fall.open_in_new Flower and pollinator numbers and diversity were significantly higher in the unmowed areas.
Surprising to the researchers, 97% of the park visitors surveyed enjoyed the unmowed portion of the park.open_in_new They did not perceive the substantial unmowed areas as “unmanaged” or “messy;” and, instead, visitors celebrated the open invitation to more pollinators and flowers.
Big things start as small things
Carving out spaces not to mow in a public space like a park will likely take some local advocacy. You might consider taking a summer to quietly observe use of the park at different times of day, noting where people walk, where people play sports, where kids run, etc. Talk to the maintenance staff. Take notes. This exercise will prepare you to present a reasoned case to your town council, or other governing board. Keep your request simple–suggesting a few areas to convert into meadow . Have a plan for how to do make the changes. Consider working with a local school to monitor the new meadow for birds, bees, or butterflies. Offer to map it in Habitat Network on behalf of the city. Find someone handy to make a sign describing the space. You can change your public parks.
We recommend minimizing the frequency of mowing lawns and encourage people to consider using select native grasses, which require less mowing because of their growth habits. Left a little longer, lawns have the potential to become a resource for a diversity of organisms–from pollinators to toads. 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) emissionsopen_in_new, and decreased noise pollution.
The video above recommends letting your lawn grow longer than average, perhaps encouraging patches of flowers, like native clovers, to bloom for bees and other pollinators. If you have a smaller lawn, consider checking your grass before mowing for small creatures that might be using the area for shelter or foraging habitat. Then, 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. And, 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.
Schools and community parks often have large, open, mowed areas for recreation. Though the fields themselves often require frequent, close mowing to keep the turf usable for sports, areas around the fields could intentionally be left to grow. Managing these patches to encourage native flowers will help local pollinators locate food sources.
Powerline right of ways
Powerline right of ways offer approximately five million acres of habitat, this is more than the area of almost all national parks in the United States.open_in_new Recent adjustments by some utility companies in different states have resulted in decreased mowing or the elimination of mowing under powerlines–opting instead to only remove tall vegetation that may interfere with their services.
In one study, powerline right of ways had a richer and more diverse percentage of bee species than nearby grasslands. Powerline right of ways also had increased numbers of parasitic species and more cavity-nesting activity.open_in_new These findings suggest that as we seek to expand our habitat for pollinators, unmowed powerlines have a role to play.
In the contiguous United States, airports’ total land use consists of +800,000 acres of potential grassland.open_in_new Most of these grassy areas are currently maintained as mowed turf. The possible benefit of transforming, this turf into viable habitat, like prairies, as Dayton International Airport has done in Ohio, seems hopeful, but raises alarms with some conservationists. Collisions between planes and wildlife do happen, mainly with birds and mammals.open_in_new The question is, will creating certain types of grassland habitat discourage the usual collision suspects? There is mixed evidence regarding this issue.open_in_new
Between 1990-2009, over 100,000 birds, namely waterfowl, collided with airplanes in and around airports.open_in_new Waterfowl are most attracted to mowed turf or bodies of water. The theory is if we turn turf into native grasslands and minimize open bodies of water, those species most likely to be involved in collisions will be reduced. The research on this is still being collected, but some data reveals that certain species’ collision numbers are down around airports that have adapted this habitat strategy.open_in_new
Already many cemeteries function as parks of sorts, home to a diversity of plants, including large and important trees. Introducing a management plan with reduced mowing could further increase the value of these spaces.
In an old cemetary in Europe, an initial assessment revealed the cemetery provided habitat for 604 species of plants and animals.open_in_new Unique from parks, cemeteries experience less daily use so disturbances are less common, which is often attractive to wildlife. Issues that could prevent cemeteries from being wildlife havens include management strategies that encourage frequent mowing, heavy use of pesticides, and encouraging non-native instead of native species.
A degree program at Oregon State University is specifically committed to educating on how cemeteries can be sustainable habitats. This includes, but is not limited to, maintaining wild spaces at cemeteries and encouraging certain landscaping practices that benefit wildlife while balancing the cultural and social needs of these sites that have historical land management practices.
A typical 18 hole golf course consists of about 130 acres with approximately half of that area maintained in manicured grass.open_in_new The other half could, potentially, include a diversity of native habitats from forest patches, to fields of wildflower, or ponds. In the United States, researchers have estimated between 40-80 species of birds can use golf courses as viable habitat.open_in_new Amphibians, reptiles, pollinators, and small mammals are also likely to use areas on the courses to access food, water, and shelter. Golf courses, with careful management, can be habitat havens.
“But where native vegetation is maintained, forests are conserved, and natural buffers around courses are developed, rare species coexist with golfers.”
Species that use these spaces must tolerate a moderate level of disturbance, such as the Eastern Bluebird (Sialia sialis). Research conducted on bluebirds nesting on golf courses in Virginia found reproduction was just as successful as at control sites. Hatching and fledging success was found to be higher on golf courses,open_in_new creating hope that some birds and courses can peacefully co-exist.
Semi-aquatic Painted Turtles (Chrysemys picta) and Sliders (Trachemys scripta), like the one pictured above, were also found to call golf courses home. They preferred golf course ponds in more rural areas over ponds found in suburban residential neighborhoods.open_in_new In fact, the trend to have neighborhoods surrounding golf courses may be counterproductive to courses that are interested in providing viable pond habitat for wildlife, as turtle abundance was lower in golf courses surrounded by developed neighborhoods than those without.
The differences between turtle success might be linked to tidier pond management in areas surrounded by neighborhoods (read about the importance of wild shorelines); increased nest predation in residential areas; greater mortality of turtles in suburban areas likely linked to automobile collisions; or a combination of these.open_in_new Optimistic evidence points to the potential that we can play golf and protect our wildlife, too.
Space is a limiting resource in our expanding, fragmented built environments. Mowing further reduces the usefulness of the remaining green pockets in our working landscapes. Positive steps can be taken to preserve wildlife habitat including changing mowing strategies and allowing strips of grass, wildflowers, or fields to fill areas in our communities. Less can sometimes mean more especially when it comes to mowing practices.