Cooperative Fish and Wildlife Research Units Program: Virginia
Education, Research and Technical Assistance for Managing Our Natural Resources

Rappahannock River Valley National Wildlife Refuge (RRVNWR) in the tidewater of Virginia is a network of both remnant and restored grasslands (with more restorations planned). Whether existing grasslands can serve as sources to restored grasslands will prove critical to the success of maintaining viable metapopulations. Within the RRVNWR complex, three units contain large, managed grasslands: Wilna, Hutchinson, and Tayloe Units. Over the past several years, surveys of grassland sites confirmed the presence of target grassland bird species, including obligate and facultative breeders such as Grasshopper Sparrows, Yellow-breasted Chats, Field Sparrows, Blue Grosbeaks, and Northern Bobwhite. This project aims to determine whether ARUs can be used to monitor avian metapopulation dynamics in grassland ecosystems at RRVNWR and collect baseline community and abundance data for long-term assessment of grassland restoration success.

Objectives:
Determine which species present in RRVNWR can be reliably surveyed by ARUs and detected by automated call identification software.Estimate species occupancy and indices of abundance (estimated by call frequency and duration) across grassland habitat patches that vary in terms of size, isolation, and habitat characteristics, and management.Evaluate community similarity among habitat patches as a function of area, distance metrics, and other habitat characteristics.