Fig. 2: Advancement in godwit migratory departure from New Zealand during 2008–2020, at the population and individual levels.
From: Advancement in long-distance bird migration through individual plasticity in departure
a Population-level advancement in departure. In blue: distribution of departures (n = 128–251 godwits per year, total = 2,423 departures; sample sizes above panel); boxplots indicate 25–75th percentile range with median departure date (white lines); whiskers extend to 1.5× interquartile range; outliers (dots) beyond this. In black: mean departure dates (filled circles) plus linear slope (solid line). Date: 1 = 1 January. b Within-individual advancement of departure date (n = 124 marked individuals observed in 3–13 years each; sample sizes above panel). Open circles = all departures; size scaled to the proportion of total migrating individuals that year (0.006–0.422 per day). Orange lines indicate within-individual slopes. Overall advancement was shown by the solid blue line (within-individual slope) and black dotted line (between-individual slope); see Supplementary Table 1a.
