Getting in sync: grassland birds and forage

CN-MR-2-Grasslandbirdsby Tamara Scully

For farmers who’ve been watching wildlife activity on pastures or hayfields during the past 10 years, a decline in the number of grassland birds won’t come as much of a surprise. For those who’ve been watching for the past 40 years, the change is even more significant. Grassland birds — bobolinks, Savannah sparrows, Eastern meadowlarks and others — have suffered a decline of 75 percent over the last four decades. At that rate, they will soon be extinct. Unless something changes.

At the University of Vermont’s Rubenstein School of Environmental and Natural Resources, researcher Allan Strong and others have been monitoring the nesting success of these birds and correlating that with a variety of farm management practices. In conjunction with Vermont’s Natural Resources Conservation Services, the research data was the basis for conservation incentive programs which have allowed farmers to implement management practices that have a demonstrated impact on the survival of grassland birds.

Managing for Birds

Open lands no longer being kept in hay or pasture are either converted to row crops, used to build housing, or no longer managed, allowing succession to occur. After the conversation, these lands are no longer hospitable to birds requiring acres of open grasslands to nest. With the change in land use patterns since 1950, Vermont has had a dramatic decrease in harvested hay acreage, amounting to a loss of 74 percent in the past 60 years. Add in today’s intensive forage management practices to that habitat loss, and major disruptions in the nesting success of grassland birds have occurred.

“Just in the past 10 years, roughly 1/2 of the farmers are cutting earlier than they did 10 years ago, and more frequently than they did 10 years ago,” Strong said. “A lot of this really revolves around a better understanding of the nutrient value of forage grass. Substantial improvements can be made in the protein content of forage when it is cut earlier in the season.”


Research

Research taken in the Champlain Valley from 2002-2007 showed that weather-related changes in hay cutting pattern had substantial impacts on whether the grassland birds could successfully fledge. The researchers determined that today’s tendency to take a first hay cutting in mid-May, as well as shortened periods of time between first and second cuttings, have directly caused a large decline in the birds’ ability to successfully fledge their young.

The first early cut disrupts the initial nesting attempt, while a second cutting curtails the attempt at re-nesting. Thirty years ago, a first cutting of hay wasn’t taken until July 4, allowing grassland birds plenty of time to nest successfully.

“We wanted to try to characterize the common management strategies that were out there in the Champlain Valley,” Strong said. “There is not enough time to nest successfully before the first cut, and not enough time between the first and second cuts.”

Today, many prime nesting fields are cut in early or mid-May. The birds will eventually attempt to nest again, although where and when are species-dependent. But a second cutting at an interval of less than 65 days will disrupt these attempts, too. For the bobolink in particular, whose success at re-nesting is lower than that of the Savannah sparrow, today’s management practices are causing too much disruption.
“Twenty-two to 54 percent of the Champlain Valley is cut when bobolinks are first attempting to fledge,” Strong said.

Once disturbed, the bobolinks emigrate to fields where the grass has been undisturbed for at least two weeks. But they will not attempt to re-nest a field where the first cutting of hay was taken after June 7. In order to be a candidate for re-nesting, the land must be cut prior to May 31.
Vermont’s EQIP Program

One result of Strong’s work has been the development of a partnership between the University of Vermont and the National Resources Conservation Service (NRCS). This partnership has made available Environmental Quality Incentives Program (EQIP) funding which promotes conservation measures on agricultural working grasslands. While Vermont’s program was funded in 2008 – 2011, it was not offered in 2012, and was offered with reduced payment incentives in 2013. For the 2014 year, the funding should remain at 2013 levels, according to Toby Alexander, NRCS biologist, who helped to implement the program. Enrollment is for a three-year incentive period, and very specific research-based criteria for enrolling land, as well as managing enrolled land, has been developed.


Management Guidelines

Guidelines call for a minimum of a 20-acre field, with a low edge ratio in order to provide enough interior nesting area. For less open land, 100-foot buffers are drawn to determine the core nesting area available. There cannot be more than 10 percent reed canary grass in the vegetative mix. Priority fields are actively mowed, with two or three cuttings per year.

All first cut hay must be taken by May 31, and a second cutting must not occur until after a full 65 day period. Should there be a plausible reason to not take the first cut prior to the end of May, the farmer may elect once in the three-year period to wait to take a first cut until after July 15, and still receive funding.

The Pasture Deferment plan, offered through Vermont’s NRCS, is aimed at beef producers. A $40.00/acre payment on a five acre minimum paddock is offered as an incentive payment to set aside the paddock for 50 days. There must be 50-75 percent grass in the paddock. The paddock cannot be grazed or managed in any way between May 15 and July 4, to enable grassland birds to fledge successfully.

Public Funding

The Bobolink Project, a collaborative, publically-funded project, has been launched by the University of Connecticut, the University of Vermont, and University of Vermont Extension. During the pilot year of 2013, the project raised $32,000, and paid $160.00/acre to delay cutting on 200 acres of grassland in the Champlain Valley. This regional effort allows the public to pay landowners directly for implementing grassland bird-saving conservation measures, offsetting the real financial implications which farmers face when altering management practices in an effort to promote conservation.

“We know it does work as a management practice,” Strong said, referring to the synchronizing of land use with the bird’s nesting cycle. While many farmers are aware of the conflict between the needs of grassland birds and today’s forage management practices, they don’t always “understand how intense the conservation issue is.”

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