The habitat use and home range analysis of Dunlin (Calidris alpina) in Chongming Dongtan, China and their conservation implications

Natural coastal wetlands are important habitats
for shorebirds while flooded agricultural croplands, may
also be useful habitats. Shorebirds in East Asia utilize an
often highly developed coastal landscape, which may be
dissected by seawalls with intertidal flats on the seaward
side, and aquaculture ponds and agricultural croplands on
the landward side. Little is known about the value of
aquaculture ponds to shorebirds. We investigated the
habitat use, preference and home range of wintering
Dunlin (Calidris alpina) in Chongming Dongtan, east
China, through radio tracking and field observations in
2006–2007. Our results indicated that Dunlins preferred
tidal flats, avoided agricultural croplands, and used aquaculture
ponds in proportion to their availability. The
probability of Dunlin usage of aquacultural ponds decreased
with increasing size of unflooded area in the
aquaculture ponds. Dunlins foraging in aquaculture ponds
had lower feeding success rate than those in tidal flats.
Thus, tidal flats may provide important foraging habitats
for wintering Dunlins, while aquaculture ponds may provide
alternative roosting and supplemental foraging habitat.
Conserving the natural wetlands on tidal flats is vital
for shorebird conservation in East Asia but at the same
time, the aquaculture ponds also could play an important
role if managed properly.