Capture methods and sampling
Dunlin individuals were captured during the autumn migration period in
2015 (12–20 September) and 2016 (26 September to 6 October). Birds were
captured on intertidal flats and adjacent lagoons behind the sea wall
where they roosted at high tide in different ways, depending on time of
day, weather conditions, and stage of the tidal cycle. Canon nets and
elastic-powered whoosh nets were used to trap birds in daylight, whereas
mist nets and dazzling with lights were used at night. A total of 791
dunlin individuals were captured. Birds were placed in keeping cages
before being processed. Birds were banded with a metal band and color
flag (upper green and lower blue). Maximum chord wing length was
measured to the nearest 1.0 mm with a wing rule, and bill and total head
lengths were measured to the nearest 0.1 mm with dial calipers. Blood
samples, 20–50 μL, were collected from some individuals by venipuncture
from the wing vein and stored in 0.001 M Ethylene Diamine Tetraacetic
Acid (EDTA). Cotton swabs were used in beaks to collect epithelial
cells, and coverts from the belly were also collected. All specimens
were stored in 75% ethanol and immediately placed into an icebox.