Ecology and Vulnerability

Virginia Rail

Background
Virginia rails are relatively small marsh birds with narrow bodies that allow them to navigate  through dense vegetation. They have brown bodies, gray faces, and reddish-brown underbodies. Similar species are the king rail and sora rail. Virginia rails breed in northern North America and overwinter in southern North America ⁶, with breeding populations in central and eastern Massachusetts. In recent years, overwintering on Cape Cod and coastal islands has increased. Spring arrival to breeding grounds throughout southern U.S. and Mexico occurs in late April, and a variety of breeding calls are heard soon after as rails begin to attract mates. Virginia rails may arrive at freshwater and saltwater marsh breeding habitat in Massachusetts and other areas in northern North America earlier than other rail species ³. Their preferred nesting habitat is cattail marshes, vegetated banks of rivers, pond edges, and even salt marshes ^5,6. Nests are typically made of marsh vegetation and are placed just above mud or water. Both males and females incubate the nest for about 20 days before eggs hatch ⁸.

Although Virginia rail populations seem to have remained relatively steady over the past several decades, human impacts and changing environmental conditions threaten them throughout much of their range. Current threats are habitat degradation, and hunting in some areas ⁶. Loss of habitat typically occurs as a result of draining or filling wetlands, and is usually associated with human development. Declining rail populations have been linked to loss of freshwater wetland habitat, which is essential for foraging and reproduction ².

Climate Impacts
Virginia rails are vulnerable to many aspects of climate change, including flooding from sea level rise, increases in storm surges and runoff ⁷. Sea level rise is projected to increase storm surge and salt water intrusion in coastal ponds and wetlands, potentially threatening nesting habitat. Virginia rails breeding in salt marshes may be impacted by changes in hydrology, sea level rise and increased storm surge sooner than populations breeding inland ¹. Warming temperatures projected under future climate change may alter wetland water levels by increasing evaporation and increasing risk of drought. In addition, changes in hydrology from increased storm events may increase terrestrial runoff and delivery of pollutants to downstream and coastal habitats. Finally, mismatches between optimal environmental conditions and the timing of important life stages are expected to occur for a number of migratory bird species ⁴.