How Landscape Factors Influence the Viability of Grassland Birds in South-Central Wisconsin
OBJECTIVE
To determine relationships between the abundance/productivity of grassland birds and landscape factors in south-central Wisconsin.
DESCRIPTION
Background: Populations of grassland birds have decreased significantly over the last thirty years primarily due to habitat loss and degradation. Current research indicates that landscape-scale factors may affect grassland bird abundance and productivity more so than factors at the field level. With less than 1% of native prairie left in Wisconsin, and an inadequate amount of other grassland held in public ownership, there is a need to develop a landscape-scale plan to manage grassland birds within agricultural regions that are predominantly in private ownership. Cooperative programs between government and private landowners are playing an increasingly important role in the protection of grassland species, but these programs could be more effective. The Conservation Reserve Program (CRP), for example, gives tax breaks to farmers who leave fields out of production for a 10-year period. The Wisconsin Department of Natural Resources (DNR) and the University of Wisconsin (UW) are conducting a long-term study of grassland birds in the Military Ridge Prairie Heritage Area (MRPHA) in south-central WI to better understand the role of landscape factors on bird populations and to develop a landscape model that can be used to determine the optimal placement, quantity, and spatial arrangement of grassland habitat needed to maintain grassland bird populations within an agricultural region. This model will help improve important cooperative conservation programs.
Study Area: The study area includes the 70 square-mile MRPHA and an
adjacent 30-square mile area. It is an agriculture region comprised of ridge
and valley topography characteristic of the Driftless Area. The MRPHA has been
ranked as the best potential landscape-scale grassland management site in
Wisconsin. While the vast majority of land is in private ownership, the study
area includes several native prairie remnants held in public trust by the
Nature Conservancy of WI. The rest of the landscape is composed of a large
number of CRP fields, pasturelands, and a significant number of agricultural
fields of hay, grain, soy and corn. The DNR and UW have collected bird data on
50 field sites throughout this extended study area. These fields include
remnant prairie, CRP, pasture and cropland. A detailed ground survey of
vegetation and land-use has also been conducted by the DNR for the entire study
area.
Proposed Tasks: We will use data collected by the DNR and UW on bird abundance, nesting success and vegetation/land-use within the study area, as well as other data layers, to determine landscape factors that play a role in the viability of grassland birds.
1) We will build a spatial database for the study area using a DNR landcover survey as well a orthophotos of Dane, Iowa and Green counties.
2) We will build a nesting success data layer using GPS coordinate points of the nest sites.
3) We will create several buffer layers around nesting sites (maximum buffer 1.5 kilometers) for landscape analysis. Landcover directly adjacent to field sites will also be analyzed. Some factors that we will analyze are:
· Percent composition of landcover categories at different buffer levels and bird species abundance, richness, and nesting success.
· Nesting success and the proximity of woody cover.
· Species abundance and elevation (ridgetop versus valley).
Our findings will aid in the development of the DNR/UW landscape model for the conservation of grassland birds in Wisconsin.
References: Sample, D.W. and M.J. Mossman. 1997. Managing habitat for grassland birds, a guide for Wisconsin. Wisconsin Department of Natural Resources PUBL-SS-925-
Proposers:
John Clark: johnclark@students.wisc.edu
Jescie Kitchell: jekitchell@students.wisc.edu
Alex Martin: aammmartin@hotmail.com
Karen Tuerk: kstuerk@earthlink.net