Fig. 4: Diverse compass course performance among species and migration routes.
From: Predicting performance of naïve migratory animals, from many wrongs to self-correction
a Compass-course performance along known routes of nine airborne migrant species (Table 2) vs. length-adjusted goal breadth (Eq. (3)). Illustrated here based on 20° precision among flight-steps, with filled symbols representing (left-right) monarch butterfly, common rosefinch, Kirtland’s warbler (Setophaga kirtlandii), willow warbler and grey-cheeked thrush, and open symbols representing the other species (depicted in Supplementary Fig. 2). Purple hexagons represent geographic loxodromes, orange diamonds geomagnetic loxodromes, brown triangles magnetoclinic courses, blue squares fixed sun compass courses and green circles time-compensated sun compass (TCSC) courses. b–f Randomly sampled trajectories (from 10,000 modelled individuals) with route-optimal population-mean headings for the above species, with colours and symbols representing compass-course as in a, for the above-named species (with the others depicted in Supplementary Fig. 2), assuming biologically relevant variability including 15° compass precision, drift, and 2.5° between-individual variability in inherited headings (see text). The top row depicts known species routes (grey arrows) between natal grounds (black hexagons) and natural goal areas (open circles), with straight lines appearing as great circles in the stereographic projection. Performance (percentage arrival) and, where applicable, also cue-transferred courses (“T”) are depicted above each panel. Photos by b D. Descousens (https://creativecommons.org/licenses/by-sa/2.0), c I. Shah (https://creativecommons.org/licenses/by-sa/4.0), d B. Majoros (https://creativecommons.org/licenses/by-sa/3.0/), e HS and f A. D’Entrement.
