Fig. 8: Relative compass-course performance and cue favourability predicted by distance and spherical-geometry factors.
From: Predicting performance of naïve migratory animals, from many wrongs to self-correction
a–i Route-optimized performance (arrival probability) vs. directional precision among flight-steps per modelled species (Table 2) for geographic loxodrome (purple hexagons), geomagnetic loxodrome (orange diamonds, right-adjusted for visibility), and TCSC courses (green circles). Species are arranged on the y-axis in increasing order of the product of the three performance gain factors (see text). Open symbols depict model-selected regression-estimated performance \(({R}_{{{\mathrm {adj}}}}^{2}\ge 0.97)\) for geographic loxodromes (hexagons) and TCSC courses (circles), including compass-specific parameters factors governing convergence in mean heading with a number of steps, spherical-geometric effects and (for TCSC courses) flight-step distance. j Performance gain (%) vs. the minimum number of flight steps and the spherical geometry factor (Eq. (18)), for TCSC courses relative to geographic loxodromes (colour-coded inner hexagons) and geomagnetic loxodromes (colour-coded outer diamonds), here when additionally considering 15° compass precision including cue transfers where applicable, 15° drift, and 2.5° between-individual variability (for other error scenarios, see Supplementary Fig. 5). Photos as in Figs. 4, 6 and by a C. Giese, c P. Gomez (https://creativecommons.org/licenses/by-sa/3.0) and d Copyright © Albert Molenaar, via Observation.org.
