Grassland bird populations are declining precipitously throughout their range and this is particularly true for the east coast populations. Throughout the east, grassland and early successional habitat continues to decline at alarming rates due to intensified agriculture, human population growth resulting in increased urbanization, and continued maturation of eastern deciduous woodlands. Grasslands throughout the world are by far the rarest ecosystem with less than one percent remaining.
Once common, grassland birds in Maryland are experiencing negative annual population trends, data from the Breeding Bird Survey (http://www.mbr-pwrc.usgs.gov/bbs/) highlight the decline in these select species:
Northern Bobwhite - 9.44 (annual rate of decline)
Grasshopper Sparrow -5.91
Field Sparrow - 4.56
Henslow’s Sparrow -11.27
Vesper Sparrow - 6.89
Yellow-breasted Chat - 2.80
Many factors are contributing to these declines, but without a doubt habitat loss is the key factor. The Natural Lands Project will be adding native warm season grassland habitat back to the working landscape on the upper Eastern Shore to help stem these declines. Work on the River and Field Campus illustrates the saying “build it and they will come” as dozens of birds dependent on grasslands and early successional habitat nest in the grasslands every year. Many of these successfully nesting individuals return year after year, something that would not be possible without maintaining quality habitat.
As part of the NLP protocol we will be conducting bird surveys pre- and post-habitat installation to document occupancy during the breeding season. We will be conducting these surveys on annual basis to record the change in bird abundance and occupancy as the grasslands change from one year to the next and the areas of shrubby cover mature.