The Yellowwood State Forest Important Bird Area is approximately 55,000 acres in size and is located in Brown County, Indiana, amongst the rolling forested hills of the Highland Rim Natural Region. The core of this IBA is the state-owned forest, which encompasses 22,000 acres, and Brown County State Park, which is approximately 16,000 acres in size, although several privately-owned properties permeate throughout the area. This heavily wooded landscape in south-central Indiana is an exceptional example of a large contiguous, forest patch and consequently supports significant populations of forest-dependent songbirds.
Yellowwood State Forest supports one of the largest populations of forest-dependent neotropical migratory birds in the state of Indiana, and its diversity of avian species may be unparalleled when compared to the mature forests located within the Highland Rim Natural Region. Forest interior species with the highest levels of abundance here include Acadian Flycatcher, Red-eyed Vireo, and Scarlet Tanager. Many species of WatchList birds also utilize Yellowwood during the nesting season, including Wood Thrush, Cerulean Warbler, Worm-eating Warbler, and Kentucky Warbler; nesting pairs probably exceed over one hundred pairs within the forest for each of these declining species. Additionally, birds listed as 'endangered' on the state registry of can be found at Yellowwood during nesting months, including Black-and-White Warbler and Hooded Warbler, with the latter species being one of the more common neotropical summer residents.
A modest timber-harvesting regime at Yellowwood State Forest has helped create several areas of early to mid-successional habitat, thereby increasing the overall breeding bird diversity. WatchList species which have directly benefited from such practices within the forest include Willow Flycatcher, Blue-winged Warbler, and Prairie Warbler, although the populations of such birds at this IBA are much smaller when compared to species more dependent on mature forests. Also, Yellowwood includes several plantings of Scotch, Virginia, and Eastern White Pine. This flora has encouraged small breeding populations of birds associated with pine and mixed forest types, such as Pine Warbler and Black-throated Green Warbler.
An immediate threat to the forest-dependent bird communities of the Highland Rim and Shawnee Hills Natural Regions is a recently proposed increase of timber cutting within state-owned forests. Historically, the state has opened up for harvest about 3.4 million board-feet of forest each year. Under the directive of Indiana's governor, that figure would rise between 10 million and 17 million board-feet. Yellowwood State Forest has been one of the properties recently sighted as a recipient of such a precipitously increased cutting regime.
Although the proposed harvesting would create more early to mid-successional habitat within the confines of Yellowwood State Forest, thereby benefiting such species as Prairie Warbler, Yellow-breasted Chat, and Field Sparrow, the loss of mature forest would equally serve as a detriment to bird communities associated with late successional habitats. Consequently, the populations of WatchList species such as Wood Thrush, Worm-eating Warbler, and Kentucky Warbler would most likely be impacted. In addition, research performed by scientists from Indiana University-Bloomington has illustrated that fragmentation and the creation of forest edges are often associated with higher predation and parasitism levels in nesting neotropical birds within this natural region. These effects, compounded with the loss of mature forest habitat, would certainly cause long-term problems for the reproductive success and population recruitment of forest interior birds at Yellowwood.