Data from: Evaluating staging habitat quality to advance the conservation of a declining migratory shorebird, Red Knot Calidris canutus

Identifying where and when population “bottlenecks” occur is critical to
the conservation of migratory species, many of which are declining
precipitously worldwide. Especially challenging is the evaluation of
changes to staging sites. These sites are indispensable links in the
migratory cycle but are typically used only briefly. We devised a
field-based approach to assess the quality and carrying capacity of a
critical staging site in Nanpu, China, for the declining, migratory Red
Knot (Calidris canutus rogersi & C. c. piersmai) during northward
migration. The Nanpu tidal flat supports 50,000-100,000 Red Knots
annually, and while there, the knots feed almost exclusively on the
bivalve Potamocorbula laevis. We simultaneously monitored changes in the
abundance of Red Knots and bivalves across the entire staging site in
spring 2018. After taking into account potential competition with other
shorebird species, we estimated that the Nanpu tidal flat was capable of
supporting approximately 1.46-1.70 times the current observed level of
usage of the site by Red Knots, and therefore is operating below, but
close, to carrying capacity with respect to food resources for Red Knots.
This result suggests that any further development of this site could harm
the EAAF Red Knot population. Synthesis and applications: Quantitative
monitoring and evaluation of habitat quality of staging sites are
essential to successfully conserve declining migratory species. In
particular, researchers and conservation practitioners should incorporate
both population size and staging duration in order to more accurately
assess the importance of different sites and to quantify how changes in
staging habitat quality may translate into changes in migrant population
sizes at both local and global scales.