Table 3.

Influence of the occurrence of eddies, filaments and current speed on heading velocity

HV ~ OW category	Intercept	Presence of eddy	P intercept /P variable	∆AIC Null
M1 – Outward phase	3.57 ± 0.20	−0.14 ± 0.40	<0.0001/NS	+1.87
M2 – Central phase	1.62 ± 0.11	0.12 ± 0.16	<0.0001/NS	+3.30
M3 – Inward phase	3.43 ± 0.25	−0.635 ± 0.29	<0.0001/< 0.05	- 2.14
HV ~ FSLE (>0.1)	Intercept	FSLE (>0.1)	P intercept /P variable	∆AIC Null
M4 – Whole trip	3.60 ± 0.51	−7.29 ± 2.78	<0.001/< 0.05	- 6.40
TV ~ Current speed	Intercept	Current speed	P intercept /P variable	∆AIC Null
M5 – Whole trip	3.51 ± 0.19	−1.51 ± 0.24	<0.001/<0.001	−27.38

Linear mixed models were independently built with individual bird included as a random effect (n = 6) for each explanatory variable. Response variables are heading velocity (HV) and travel velocity (TV). The Okubo-Weiss parameter is a binary factor coding for the occurrence of eddies (0: absence, 1: presence). Current speed and FSLE are continuous variables. Only FSLE values >0.1d⁻¹ were selected to test for the influence of filaments on HV when penguins were within a filament. Significant coefficients (mean ± se) are in bold. P p.value, NS non-significant. _{∆AIC Null} shows the AIC deviation from AIC of the null model