Can Birds and Livestock Coexist? Rotational Grazing and other Bird Friendly Farming Techniques

Aug. 23rd 2024

Savannah Sparrows are common grassland birds in Vermont pastures and hayfields. Photo by Margo Burnison, Audubon

Typically, when we think about conserving bird habitat, we think of huge swaths of forest and untouched nature away from civilization. But what if we told you a critical habitat for some of Vermont’s most beloved bird species was farms? Grassland birds and farms can not only live in harmony, but can actually have a co-beneficial relationship.

Land uses for livestock vary drastically and so do their impacts on birds. Audubon Vermont is focusing on several strategies, including certain approaches to grazing, in which agricultural and conservation objectives are compatible. In fact—grassland bird habitat may actually depend on grass-fed cows to maintain an open landscape that would otherwise be lost.

Diverse groups of birds provide balance by reducing populations of potentially harmful pest insects like caterpillars, weevils, cutworms, beetles, and flies that can negatively impact crop yields and the health and welfare of livestock animals. At the same time, grassland birds, especially in the northeast, depend on human-altered agricultural landscapes where their preferred grassland habitats are actively maintained as open, grass-dominant vegetation.Grassland bird habitat is decreasing across the country, and Vermont, with the transition of pasture or hayfields into other crops or land use types as well as the overall intensification of agricultural practices.

In general, good pasture management to maintain soil health and forage diversity, nutrition, and production with ample rest and regrowth, is also good for many bird species. Sustainable grazing practices that enable long-term viability of grasslands with adequate maintenance of vegetative structure and adequate periods of rest without disturbance, can provide birds with essential breeding, shelter, and forage requirements.

With a variety of grassland bird species comes a variety of habitat, feeding, and nesting needs, so not all species are likely to occur on one farm, but there are some general concepts to be familiar with when encouraging most grassland birds.

• Habitat size: Bigger is better. Fields larger than 25 acres will be most attractive. Bobolinks and Savannah Sparrows may use fields as small as 7-10 acres, but Eastern Meadowlarks prefer at least 20 acres or more.

• Field shape: Square, rectangular, or circular fields with a high interior area and low edge effect are better than long, narrow, or irregular shaped fields. While birds often forage in all parts of a grassland, the greatest number of nests are in the central section.

• Vegetation composition: Grass dominant, of course! Fields with 50 to 75 percent or more grass cover at least 12 inches tall with some forbs (vetch, wildflowers, and others) and very few to no woody plants is most beneficial.

• Location, location, location: Grasslands surrounded by similar fields and an open landscape view on a hilltop are preferred over an isolated field surrounded by forest or thick hedgerows. Many species typically return to the same areas to nest year after year, even if those fields are hayed and they are not successful, which can lead to an “ecological trap.”

• Breeding activity: Timing is everything. Eastern Meadowlarks, American Kestrels, and Norther Harriers arrive earlier than Bobolinks and different species have a variety of nesting habits and timelines, but there are some overlapping critical windows in May and June especially.

Rotational Grazing

This past year, Audubon collaborated with Organic Valley to learn more about dairy farm operations to better inform our Bird-friendly Farming, Bobolink Project, and certified Conservation Ranching programs and beyond. Fencing in pasture systems can provide favorable conditions for birds with posts serving as ideal singing perches and electric fencing potentially reducing predation by raccoons, skunks, foxes, and coyotes.

More importantly, we’re starting to understand that grass-fed pastured livestock operations in particular that use intensive rotational grazing systems can maintain production and forage quality for their animals while simultaneously providing significant habitat for grassland birds. Generally, rotational grazing is a method where pastures are subdivided into many smaller areas (referred to as paddocks), only a small strip is grazed at a time while the remainder of the pasture “rests” and the herd is moved very frequently.

In contrast, continuous grazing gives cows access to the whole area for long periods. There are advantages and disadvantages of each method for practical, economic, and ecological reasons. However, it’s important to note that we’re finding the time cows have access to an area to graze has a larger impact on birds and habitat quality than animal stocking density and area size.

Initial costs for rotational grazing systems do tend to be higher for fencing and water distribution supplies for each paddock and this method requires more hands-on management and careful monitoring of forage supply, but there is a long list of benefits to farm productivity, livestock, and birds alike. This system allows for the optimum rest and recovery time of forage species and will provide the highest quality pasture for livestock based on energy, protein, palatability, and digestibility.

Other benefits of intensive rotational grazing include weed control, increased grass productivity, even manure nutrient distribution, and more livestock on less land due to increased land use efficiency. In addition to bird diversity, intensively rotated pastures support several times the abundance of grassland birds compared to continuous grazing or even simple rotation (still uses paddocks, but fewer, larger, and less frequently rotated), both of which may create large areas lacking diversity in vegetation structure. Below are some examples of small adjustments and actions that may be considered for livestock grazers for grassland birds if they are within the means of farm operations.

• Graze every other paddock (instead of adjacent) to ensure more protective cover and less concentrated disturbance.

• Hay or graze areas near trees, roads, and shrubby areas first and delay the center of the grassland (the better nesting habitat) from mowing or grazing as long as possible.

• Change stocking density throughout the season (lower in late spring-early summer during the most crucial and vulnerable time of breeding bird season, then increase in late summer and fall when most birds have had the chance to fledge).

Other bird-friendly practices

• Disturbance frequency and remaining height of vegetation both impact bird reproductive success in grasslands. As conditions allow, the longer rest periods between grazing events, the better. Ideally 40+ days are needed for many birds to complete a nesting cycle.

• In addition to grazing, a grassland may also be hayed for winter feed or “clipped” between grazing events to stimulate new growth for the next round of grazing. Cows (and other livestock, especially horses) can be selective about what they prefer to eat, leaving a pasture “patchy” with vegetation of varying heights.

• Another strategy is to use alternative mowing patterns that allow birds a better chance to escape, especially young grassland birds who cannot fly for up to 10 days after leaving the nest. Lines mowed back and forth, starting at one end of the field to the other or mow from the center outwards in a circular pattern. Flushing bars can also sometimes be attached to mowing equipment to warn adult birds before the mower runs over the nest.

• Sometimes the only viable option for a farmer to create a bird-friendly grassland is to set aside a separate area designated for wildlife habitat. Perhaps this area is not reliably productive, hard to access, more shaded, or more flood-prone. Whatever it may be, the most effective use of this area may be to set it aside for habitat.

These methods may be more accessible to organic farmers who can receive a higher premium for their milk and meat. The higher cost of operations and land space needed for organic farming benefits the environment and livestock, but gets passed on to the consumer with more expensive dairy and meat products.

There is a growing awareness and interest in the value that biodiversity brings to farms and many are working hard to think about ways to incorporate those values in a sustainable economic model. There is great power in small actions by individual landowners that can have a global impact on bird conservation when vulnerable species have the opportunity to reproduce successfully in their preferred habitats.

Overall, rotational grazing has the potential to be a system that supports ground-nesting grassland birds while benefiting livestock. Audubon Vermont’s Bird & Bee Friendly Farming Program will continue working with farmers and partners to find a balanced approach to support farms and wildlife.