By Bryan Watts
Whimbrels are large, highly migratory Holarctic waders with low reproductive potential and delayed recruitment that require high juvenile and adult survival to sustain populations. Whimbrel populations (Hudson Bay, Mackenzie River) that utilize the Western Atlantic Flyway are believed to be declining by 4% annually since the early 1990s and have likely been declining since at least the 1970s. Halting and reversing population declines is a priority that will require collaboration on research efforts to fill information gaps and coordination of management activities on a flyway scale.
CCB biologists have been working with whimbrels since the 1990s. We have documented ongoing declines within a primary spring staging site in Virginia, tracked a few dozen adults with satellite transmitters throughout their annual cycle, identified a new breeding population, delineated the primary overwintering site in Brazil and all major spring and fall staging sites, identified migration pathways, assessed adult mortality rates, supported work with hunting policy and worked on staging ecology during both spring and fall. In 2011, CCB developed a “blueprint for conservation action” focused on whimbrels using the Western Atlantic Flyway. Since that time we have pursued a conservation agenda with many partners focused on overcoming known limiting factors. We have had success on several key fronts.
The National Fish and Wildlife Foundation selected the whimbrel as one of three “umbrella” species (along with American oystercatcher and red knot) to represent their commitment to reverse the widespread declines of shorebirds using the Western Atlantic Flyway. CCB along with several partners (Manomet, GA DNR, SC DNR, TNC, Canadian Wildlife Service) received one of the first awards under this program. The project will build on the conservation blueprint developed nearly a decade ago and work to construct a conservation infrastructure.
Elements of this infrastructure include 1) establish a whimbrel working group (WWG) composed of biologists and managers from throughout the Flyway that are engaged with whimbrel efforts, 2) develop approaches to collecting the demographic data needed to construct an age-structured population model, 3) continue ongoing population monitoring and expand monitoring to additional key sites, 4) map critical whimbrel sites throughout the Flyway and 5) begin to improve conditions within critical sites. The WWG is intended to provide participation and input from all interested parties and to facilitate the free exchange of information and ideas. Although some progress has been made on quantifying demographic rates, there remain gaps in key life stages that need to be addressed. Ongoing monitoring is key to providing the metrics of success needed for informed management. Stay tuned… we will provide updates on progress as events unfold. Delineating critical locations throughout the Flyway will facilitate the planning and activation of ground efforts focused on improve conditions for whimbrels.