Figure
3 Comparisons of (a) female and (b) male bill and wing lengths of
dunlins sampled in Jiangsu in the autumn migration in 2015 (purple
triangles) and 2016 (green circles). The mean ± standard deviation
values for each year are shown at the top and side of each graph.
Significances differences between years are indicated by*P< 0.05, according to either t -test or Mann–Whitney
U-test.
For males,
bill
and total head lengths were significantly different between Alaskan and
Beringian lineages (bill length, t = 2.172, df = 54,
two-tailed P = 0.034; total head length, t = 2.769,df = 85, two-tailed P = 0.007) (Fig. 4a). Bill and total
head lengths were shorter in the Alaskan lineage than in the Beringian
lineage. By contrast, wing length was longer in the Alaskan lineage than
in the Beringian lineage. For females, bill and total head lengths were
both longer in the Alaskan lineage than in the Beringian lineage.