A secretive marsh bird, the Sora (Porzana carolina) begins its fall migration in late summer arriving from northern breeding ranges to Atlantic coastal marshes. Their arrival to the Jug Bay portion of the middle Patuxent River correlates with the fall maturation of Wild Rice (Zizania aquatica). The Soras weave through the dense vegetation of the marsh to forage for fallen rice seeds in the mud. The seeds are high in carbohydrates and are nutrient dense allowing the Soras to quickly accumulate enough body fat to complete their migration south; thus making Jug Bay an important stopover habitat for this species’ migration. Historically, Soras were abundant on the Patuxent River. In the 1800s and early 1900s, they were a popular game bird, hunted in incredibly high numbers using a special push boat and shotguns. Their popularity as a game bird has since then declined along with their abundance on the Patuxent. Greg Kearns, Park Naturalist II at Patuxent River Park and Michael Haramis of Patuxent Wildlife Research Center-USGS, conducted banding and telemetry studies of the rails from 1993-19991. They discovered a sharp decline in the population in 1999 that was correlated to the overgrazing of rice by resident Canada geese as well as a strong El Niño season in 1998, which altered the jet streams to an abnormal westerly flow. After Greg and his team spent 16 years directing the restoration of the rice stands in Jug Bay, the banding and telemetry study of soras was revived as a result of him receiving the Cove Point Natural Heritage Trust grant.

The Virginia rail (Rallus limicola) shares the same habitat as the Sora, but prefers slightly higher and drier areas of the marsh and their shorter toes reflect this. Their longer beak is geared more toward consuming invertebrates and not seeds like the wild rice seed the Sora prefers. Soras concentrate here in much higher numbers accordingly, often outnumbering the Virginia rail at least 5:1. The Virginia rail can adapt to a wider variety of habitats such as brackish and salt marshes as well as tolerate a colder climate. They arrive later and tend to stay later than the sora, often found over wintering here unlike the Soras that have mostly departed by late November. They tend to breed here whereas the Soras breed as far North as the Northwest Territories of Canada.

This study began in August 2017 incorporating the use of an automated telemetry tracking network called Motus (meaning “movement” in Latin) operated by Bird Studies Canada. The Motus network contains over 638 receiver stations (874 worldwide, as of November 2019) that provide us with access to tracking stations in eastern North America, Central and South America as well as some in the Caribbean Islands. This widespread international connection allows us to track the full cycle migration of individual birds. We erected the first two inland tracking stations in Maryland, one at Patuxent River Park in Upper Marlboro, the other at Newtowne Neck State Park in Compton. These two stations detect the rails fitted with 1.6 gram transmitters as they leave their stopover habitat to head further south for winter and possibly their return in the spring. Conjointly, the system collects detection information on other species studied using the Motus system that fly by our tracking stations. The transmitters are on the same 166 MHz frequency with individual digital coding to delineate each individual bird and species.