Background
The prairie ecosystem is one of the most threatened habitats in the state of Illinois.
In the years since European settlement, native prairie has virtually disappeared
in the state. Over the course of the last century, prairies have been converted to
agricultural lands and then lost to urban development. As the prairie disappears,
so does a unique assembly of plants and animals. Across the Midwest,
species such as Henslow's Sparrow, Grasshopper Sparrow, and
Greater Prairie-Chicken are declining with the loss of their breeding habitat.
Although many grassland bird species associated with the prairies have been able to
adapt to hayfields and pastures, summer mowing and intense grazing pressures affect
their breeding capabilities.
Recently there have been several prairie restoration projects to return parcels
of land to their former condition as well as projects looking to
manage other lands to protect endangered species.
In order to improve the success of these projects for grassland birds, the birds'
reproductive requirements need to be better understood.
The Project
This project is a joint venture of Dr. James Herkert,
Project Manager for the Illinois Endangered Species Protection Board,
and Dr. Scott Robinson, Professor at the University of Illinois at Urbana-Champaign.
Dr. Herkert has advanced the study of grassland birds in Illinois through
his research of grassland community composition and the habitat requirements
of different grassland bird species. The purpose of this project is two-fold:
first, to characterize the reproductive success of grassland birds, and second,
to determine if successful reproduction varies according to differences in
management practices or habitat. The results of this research should enhance
the general knowledge of grassland bird biology, as well as contribute to
prairie restoration and management schemes.
The Study Site
As part of the grassland project, the fields of the
Midewin National Tallgrass Prairie in Wilmington, Illinois
are being studied along with several other sites in Illinois.
At each site, selected fields are regularly searched for nests
from mid-May through the beginning of August.
Nests that are found are then monitored on a 3-day cycle
until they become inactive.
Census points are marked at 250-300 meter intervals in the
selected fields and a census of all birds seen and heard
during a 5-minute interval is performed at each point
twice during the summer. Vegetation analysis is also done
around each census point.