Baseline Bird Surveys of Plum Trees Islands National Wildlife Refuge: 2017, 2018 and 2019 Seasons Final Results

B. D. Watts, The Center for Conservation Biology
B. J. Paxton, The Center for Conservation Biology


The Chesapeake Bay is one of the most productive aquatic ecosystems in the world and plays an important role in the life cycle of many bird species (Duerr and Watts 2012). Each year, the rich resources of the Bay attract millions of waterbirds of 140 species from throughout the western hemisphere (Erwin et al. 2007, Watts 2013). Dependency on the Bay varies from species that stopover for a few days during migration to species that live out their entire life cycle within a single tributary. Because many waterbirds are top consumers and collectively require a broad array of resources they represent sensitive, cost-effective indicators of overall ecosystem health. Many species that depend on the Bay are of high international, national or regional conservation concern (Watts 1999, 2016). Plum Tree Island National Wildlife Refuge includes some of the most significant marsh habitat within the lower Chesapeake Bay. Established in 1972 when the site was transferred from the U. S. Department of Defense to the U. S. Department of the Interior, the site supports the largest contiguous patch of tidal salt marsh within the lower Chesapeake Bay including extensive low marsh (dominated by smooth cordgrass - Spartina alterniflora and black needlerush - Juncus roemerianus), high marsh (dominated by salt grass - Distichlis spicata and salt meadow hay – S. patens), a long marsh-upland ecotone (dominated by shrubs including saltbush - Iva frutescens or Baccharis hamilifolia and wax myrtle – Myrica cerifera), and scattered hummocks of maritime forest and low-profile dunes and beaches. Although the site is included within an Important Bird Area (Watts 2006) and is known to support bird species of conservation concern (e.g., Watts and Rottenborn 2002, Wilke et al. 2005, Watts and Smith 2015) there has been no attempt to survey the site in order to build a baseline dataset needed to understand the importance and role of the site within a regional context.