FIGURE 3 Effect of interannual differences in the date of 50%
snow cover (left column) and accumulated thaw-degree days on 10 June
(right column) on the clutch size (a and b ) and number of
nests (c and d ) of black brant, snow geese, semipalmated
sandpipers, and Lapland longspurs at a site on the Colville River,
Alaska. Clutch sizes were monitored for brant, snow geese, and
semipalmated sandpipers from 2011–2018, and Lapland longspurs from
2015–2018. Nesting effort was monitored on known-area plots for all
four species from 2015–2018. Circles represent year-specific values
(±SE for clutch size), and solid lines represent the best-fit
least-squares regression ±95% prediction interval (dashed lines).
Species-specific colored triangles to right of figures represent slope
parameters that significantly differ from zero. See Table 4 for
estimates (±95% confidence interval) of slope parameters. Ordinal date
148 is 28 May