Strong migratory connectivity indicates Willets need subspecies-specific conservation strategies

By combining all available banding and tracking data, we found that
Willets (Tringa semipalmata) have strong migratory connectivity between
breeding and nonbreeding locations at the range-wide and subspecies
levels, exposing the two subspecies to varying threats such as hunting for
the eastern subspecies (T. s. semipalmata) and climatically-altered
coastal habitats for both subspecies. We found that Western Willets (T. s.
inornata) primarily used nonbreeding habitats along the Pacific Coast of
the United States, although their reported nonbreeding range extends to
the U.S. Atlantic and Gulf Coasts and the Pacific Coast of Central and
South America. Eastern Willets wintered in Central and South America,
which covers much of the subspecies’ known nonbreeding range. By
quantifying migratory connectivity within and between two subspecies, we
could suggest subspecies-specific threats and potential limiting factors
in the breeding and nonbreeding periods of the annual cycle of a declining
migratory shorebird. Effective management of the species will likely
require a range of conservation strategies across the diverse nonbreeding
regions the two subspecies occupy within the United States, Central
America, and South America. However, more data are needed from Willets
breeding in mid-continent North America to understand the complete extent
of overlap of the two subspecies throughout the annual cycle. The strong
migratory connectivity documented here highlights the need to manage
Willets by subspecies and protect a diversity of breeding and nonbreeding
habitats, which will benefit the conservation of other shorebird species
that overlap with Willets throughout the annual cycle.