Figures and data
Hypothetical foxtrot migration and dynamic winter range scheme.
a) Foxtrot migration, Q. mig. – Quick migration (spring and fall migrations). b) Dynamic winter range.
Quick and slow migration patterns of Rough-legged buzzards throughout an annual cycle, termed ‘foxtrot migration’ for quick referencing.
Q – quick migration. Qf – Quick fall migration (orange), Qs – Quick spring migration (yellow), S1 – Slow migration, 1st phase (light blue), S2 – Slow migration, 2nd phase (dark blue). a) Change in the latitude of 43 Rough-legged buzzards during the year, red line – mean latitude of all birds, black vertical lines – mean dates of start and end of the migration phases, blue vertical line – mean date of the minimum latitude. Grey, sky blue, and piggy pink shaded areas – standard deviation of the means. b) Migration map. c) Difference in the migration parameters between the migration periods. Lines on the direction plot (down, right) represent the mean value for each bird; arrows represent the mean direction.
Parameters of the rough-legged buzzards’ migration.
Vegetation land cover during quick and slow migration.
a) Quick migration. Spring and fall migration together. b) Slow migration. 1st and 2nd phases of the slow migrations together. c) Migration map.
Slow migration and snow cover conditions.
a) 95% Minimum convex polygons (MCPs) of Rough-legged buzzards during winter. Arrows indicate the direction of the movement across months. OCT – October, NOV – November, DEC – December, JAN – January, FEB – February, MAR – March, APR – April. b) Snow cover conditions for the real situation (black) and two hypothetical situations – if birds spend the winter in the place where they arrived after the fall migration (green) and if birds fly directly to the southwest and stay there all winter (red). Dots represent mean values, error lines – standard errors.
Winter range representations.
Red – breeding range, blue – winter range. a) Migration cycle of Rough-legged buzzard; arrows represent migration (solid line – quick migration, dashed line – slow migration). b) Winter range without heterogeneity shown. c) Winter range with spatial heterogeneity. d) Winter range with temporal heterogeneity; the numbers indicate the months the birds are common in the outlined area.
