Research Task: RB00CNG.14.0
Task Manager: Janet Ruth
Endemic grassland birds have shown steeper, more consistent, and more widespread declines than any other behavioral or ecological guild of North American avian species. Understanding habitat relationships is essential for conservation of such species of concern, since knowledge of the range of habitats that a species can use could facilitate achievement of management goals. Research identifying vegetative structure and composition associated with select breeding grassland birds is limited, and virtually nothing is known about grassland structure and composition as used by wintering populations. In the southwestern U.S. and Mexico, where many of these grassland birds winter, major resource management issues potentially affecting their status are grazing regime and fire effects on bird habitat. The objectives of this task are to understand how wintering grassland birds use habitats (vegetative structure and composition); how winter habitat use is affected by land use practices such as grazing; and how wintering grassland birds respond to wildfire and its effects on grassland habitat. The first phase of this project, studying the vegetative habitats used by wintering sparrows, was conducted from 1999–2001 on seven sites in southeastern Arizona semidesert and Plains grasslands. An opportunity to address issues related to fire was presented in April 2002, when the Ryan wildfire swept through 38,000 acres of foothills and grasslands at the southern end of the Sonoita Valley, Ariz. The fire burned over 90 percent of the Audubon Appleton-Whittell Research Ranch, one of the project's research sites. This offered a valuable and unexpected opportunity to conduct a second phase of post-fire research (2003–2005) to determine the effects of such a substantial fire on the wintering grassland birds on two of the seven sites studied before the fire (one burned, one unburned). Research results will help fill substantial information gaps concerning the impacts of fire on bird communities in grassland ecosystems, especially birds that use these habitats in the winter, and will better inform conservation efforts.
For more information contact Janet Ruth