Bird Use of Early Successional Sandbar Vegetation: What Do We Lose by Managing Sandbars for Plovers and Terns?
Abstract
In the Missouri National Recreational River (MNRR), riverine sandbars created by periodic floods are initially used by two federally listed bird species the Interior Least Tern (Stern antillarum athalassos) and the Piping Plover (Charadrius melodus). These sandbars then provide opportunities for recruitment and establishment of early successional cottonwood-willow forest, which supply habitat for a wide array of birds, as they become vegetated and unsuitable for Terns and Plovers to nest on. While nesting habitat for listed species can be maintained by vegetation removal, the biodiversity associated with an establishing riparian forest is relinquished. An understanding of the current status trajectories and biological tradeoffs is necessary for a balanced ecosystem-based approach to sandbar management. We are assessing conditions and dynamics of riparian vegetation and land bird diversity during both breeding and migration seasons. My objective is to determine the degree that set-aside sandbars support diverse native plants, land birds, and cottonwood forest establishment; as they need to be actively contributing to the MNRR "Outstandingly Remarkable Values" as part of the Wild and Scenic rivers Act. With nearly half of our targeted data collected, we have observed some changes in nest survival and species that may be due to high water levels. Overall nesting success appears to be similar to other habitat types and may have benefited from high water levels increasing separation of sandbar habitat from mainland potentially reducing predation.