Monday, October 9, 2017

The Birds and The Bees and Management Decisions

By Beth Sullivan
As summer winds up, our management goals and efforts change a bit. Growth is slowing, we no longer battle vines that grow in front of our eyes covering trails. Now we decide what stays and what goes for the next six months.
We try to cut back the invasive plants, no matter how beautiful, before they can spread their seeds and berries. It would be nice if we could keep them from growing back all together, but preventing the wind from catching the plumes and birds from eating the berries are the best we can do.
Along roadsides we will begin cutting back the summer’s growth to expose the stone walls that are so beautiful and become true works of art when coated with snow. Sadly, the clearing along the roadsides also exposes the summer’s litter left behind by thoughtless travelers. Litter pickup is an education and a blog in itself.

How to overwinter our fields

Grassy farm fields, managed for hay, are cut several times a year to harvest the best and most valuable grass for farm animals. A secondary benefit of multiple mowings each season is that it inhibits the growth of non-grass plants we refer to as forbs: flowering perennials and annuals that have different texture and are not desirable for inclusion into animals’ diets. A field managed for hay and filled with grass is also most attractive to certain bird species that require large open tracts for nesting. Bobolinks, Grasshopper Sparrows, and Eastern Meadow Larks all look for large grass dominated fields for nesting. Unfortunately their nesting coincides with harvest times, and most of these species have nest destruction and failure due to the haying activity. That is the main reason for these species being in decline now. The Wequetequock Cove preserve was a perfect example of a hay field for many years, harvested several times a season. After acquisition by Avalonia in 2010, the grassy fields were allowed to be undisturbed for the entire nesting period, and there were a number of pairs of Boblinks observed, and they successfully fledged many young.
Bobolinks nested in the tall grass meadows at Wequetequock Preserve. 

Haying practices destroy nest sites before young Bobolinks can fledge.

This year milkweed and other flowering plants have begun to replace grasses.

As time passed, and mowing was only done in the fall, these fields have gradually been reclaimed by the flowering forbs. The grasses are being overtaken by lovely Goldenrod, Joe-Pye weed, Dogbane and the much needed Milkweed . All these plants change the composition of the field and attract new species. There are far more pollinators present now. The Monarch butterflies are more abundant this year than the past several, and the population is supported by all the Milkweed host plants.

Missing the Bobolinks

Walking around the fields this year was a very different experience from several years ago. Still beautiful. But one big change seems to be that there are no more Bobolinks. Other birds, such as Song Sparrows and Red-Winged Blackbirds, nested there and perched on the stiffer stems of Goldenrod. The wider variety of plants makes for a greater diversity of creatures using the areas. Small mammals like the small openings between stems and clumps of plants. A wide array of insects use the plants for green grazing as well as nectaring on the flowers. Different birds use the fields for eating the seeds and eating the insects. Larger mammals and birds of prey hunt the smaller mammals. It might be said that a diverse field is a more productive habitat. But then, what about those very special creatures that rely on the grasses? We need to support those species in decline. It is a management dilemma.
A more diverse field has more to offer pollinators. 

Goldfinches and others feast on seeds in fields through fall and into winter if not cut early.

Cutting fields early will help prevent invasive, though beautiful, Porcelain berries from spreading.

This field has been mowed and the seeds on the ground and the piles of grass will provide food and cover for small mammals over the winter.

What you will notice, is that Avalonia manages their fields in a variety of ways. Some are cut early in the fall to encourage more grass but still allow the flowering plants to finish their job for the pollinators. Often, patch areas are left tall just for a little cover. Other fields will be cut in the spring, allowing the seeds to disperse from the flowering plants and grasses, but also to provide habitat for overwintering insects and small mammals.
All are great places to investigate over the cold seasons ahead. Wequetequock is mowed now, we will encourage grasses to lure back the Bobolinks. In the winter and spring, water will stand in low areas and attract shore birds and waterfowl.
Next time you visit a field area - Wequetequock, Dodge Paddock, Knox, Fennerswood, Preston Nature Preserve, or Walton Meadows - take a moment to look a little closer, and see if you can detect what the management plan is.

Photographs by Beth Sullivan

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