USGS Study of grassland songbirds being conducted in Sheyenne National Grasslands
by Janet HansenArticle taken from The Ransom County Gazette, Monday, July 26, 1999
Are you familiar with the saying, "Getting up with the birds?" There are six people who have been working out of Sheldon, North Dakota since mid-May. They have been literally "getting up with the birds" for the past two months.
They rise at about 4:00 a.m. in order to be out to their assigned grassland site by 5:30 a.m. This is the best time to study the nesting habits of birds.
The team is working on a research project for the United States Geological Survey (USGS) which examines what effects grassland size and the habitat surrounding the grassland have on the nesting success of grassland songbirds. They are hired by Northern Prairie Wildlife Research Center at Jamestown.
The Prairie Pothole Joint Venture (PPJV), a part of the North American Waterfowl Management Plan, identified the need for such a study. It had become apparent that the populations of some of the grassland birds had been declining. The PPJV would like to stabilize or increase the bird populations in the grassland and wetland areas in their region. In order to attempt to accomplish that goal, they must understand what type of habitat the birds prefer. This includes not only the immediate habitat in which they choose to nest, but the influence the size of the area and the surrounding habitat has on where they choose to nest and how successful they are at raising their young. Eleven study fields are being monitored in the Sheyenne Grasslands area. Some are small neutral fields. This means the core area being studied is less than 125 acres in size and is surrounded by other grasslands or wetlands or small grain crops.
Some of the study fields are small hostile fields. These areas are also less than 125 acres in size, but are surrounded by trees. These areas are referred to as hostile because it is believed by researchers that the trees are a hostile environment for the grassland songbirds. The reason for this is that they may harbor predators. Wooded areas can hide raccoons, skunks, and snakes, as well as being perch sites for raptors (birds of prey). All of these predators would endanger the birds and render this type of site unsuitable for successfully raising baby birds or fledglings. The wooded areas may also be perch sites for Brown-headed Cowbirds which are termed "parasites". They lay their eggs in other bird's nests instead of hatching and raising their own young.
Large sites of both the neutral and hostile varieties are also studied. The large sites are more than 600 acres, or almost a square mile in area.
Jill Dechant, an ecologist with Northern Prairie Wildlife Research Center, oversees the study. She visits the study sites regularly to count birds and make sure field operations are running smoothly. Researchers are hired to work every day, from 5:30 a.m. to late in the afternoon. They spend their days finding nests and recording how many eggs or young are in each nest. They must brave the elements each day, but have learned to dress appropriately for the weather. The worst problem to deal with, according to Dechant, is the large number of mosquitos.
Field study sites were set up in tallgrass prairie areas in the Crookston and Glyndon, Minnesota areas last year. This summer the Sheyenne National Grasslands was added to the study.
Some of the people hired by the research center are seasonal biologists. Some are undergraduate students. Some are working on degree programs in wildlife management or ecology. Some of the people helping with the project are working totally on a volunteer basis.
The people in the Sheyenne Grassland USGS crew rented a house in Sheldon and use that as their headquarters and sleeping quarters. They form a diverse group. They come from such far away places as Pennsylvania; Syracuse, New York; Vancouver, British Columbia; and Illinois.
They have all come together to study birds in a habitat which is dwindling in acreage in the United States. In fact, Dechant states, "Of the original tall grass prairie that was here before settlement by Europeans, only about 1% remains."
Researchers have noted that the number of birds in a certain area sometimes fluctuates greatly from year to year. They believe that this may be due to climate patterns, changes in habitat caused by management actions or by natural disturbances, or the birds' previous success in raising young in a certain area. More information is needed on all of these variables.
The birds being studied most closely in the Sheyenne Grasslands area are Savannah Sparrows, Clay-colored Sparrows, and Bobolinks.
The researchers go out early in the morning and search their study sites for nests. Since grassland birds hide their nests in the tall grass, the nests are hard to find. The birds are usually sitting on their nests in the early morning hours, so the nests can be found by randomly flushing the birds from their nests. The researchers also use other methods such as sweeping the fields with sticks or using behavioral cues of the parent birds.
The study areas are gridded out in a matrix design, by pounding sections of PVC pipe into the ground at 50 meter intervals. The stakes are numbered and marked on a map so the exact location of each nest can be plotted and its location recorded. When a nest is found, the specific details of the surrounding habitat is recorded. Vegetation, patch size, and landscape features are noted as well as the number of eggs found in the nest.
The team marks each nest they find with a pink flag. That allows them to find them again. They continue to monitor each nest every third day.
Data is collected as to how many eggs in the specific nests actually hatch or produce nestlings, and how many of these nestlings live long enough to successfully leave the nest. Notation is also made if the nest has been "parasitized" or contains an egg or eggs from a bird such as a Brown-headed Cowbird.
Douglas Johnson, leader of the Grassland's Ecosystem Initiative at the Northern Prairie Wildlife Research Center in Jamestown, analyzes the crew's data and interprets its results.
Jill Dechant helps to count and record the number of birds of each species found in each specific area. She states, "The Sheyenne Grasslands are high quality grasslands, and are among the best of the unbroken, unfragmented areas that are left." She feels it makes a good area to study and plans to send another crew to study there next Year.
Access to the Sheyenne Grassland study sites have been granted by the US Forest Service.
The group will be winding up their work at the end of July and more studies will be done in the area next summer. When the study is finished, the PVC stakes will be removed and the land will be left as it was before the study began.
For those who are interested in more information on the effects of management practices on various grassland birds, you can find extensive information at the following website: http://www.npwrc.usgs.gov/resource/literatr/grasbird/grasbird.htm
