Diego-Rasilla, F.J., Pérez-Mellado, V. & Pérez-Cembranos, A. Spontaneous magnetic alignment behaviour in free-living lizards. Sci Nat (2017) 104: 13. doi:10.1007/s00114-017-1439-7
Several species of vertebrates exhibit spontaneous longitudinal body axis alignment relative to the Earth’s magnetic field (i.e., magnetic alignment) while they are performing different behavioural tasks. Since magnetoreception is still not fully understood, studying magnetic alignment provides evidence for magnetoreception and broadens current knowledge of magnetic sense in animals. Furthermore, magnetic alignment widens the roles of magnetic sensitivity in animals and may contribute to shed new light on magnetoreception. In this context, spontaneous alignment in two species of lacertid lizards (Podarcis muralis and Podarcis lilfordi) during basking periods was monitored. Alignments in 255 P. muralis and 456 P. lilfordi were measured over a 5-year period. The possible influence of the sun’s position (i.e., altitude and azimuth) and geomagnetic field values corresponding to the moment in which a particular lizard was observed on lizards’ body axis orientation was evaluated. Both species exhibited a highly significant bimodal orientation along the north-northeast and south-southwest magnetic axis. The evidence from this study suggests that free-living lacertid lizards exhibit magnetic alignment behaviour, since their body alignments cannot be explained by an effect of the sun’s position. On the contrary, lizard orientations were significantly correlated with geomagnetic field values at the time of each observation. We suggest that this behaviour might provide lizards with a constant directional reference while they are sun basking. This directional reference might improve their mental map of space to accomplish efficient escape behaviour. This study is the first to provide spontaneous magnetic alignment behaviour in free-living reptiles.
Origen: Spontaneous magnetic alignment behaviour in free-living lizards | SpringerLink
“The molecular mechanism of magnetoreception and animal navigation”. The fellowship comes from a partnership with Beijing Computational Science Research Center (CSRC) and Xie Lab at Peking University (PKU), aiming at bridging biology and physics to resolve the molecular mechanism of magnetoreception and navigation in animals.
Domínguez-López, Moisés E.; Diego-Rasilla, Francisco J.; Ortega-León, Ángela M. (2016). Effects of sex and microhabitat structure on escape behaviour in the diurnal gecko Gonatodes albogularis. Animal Biology, 66(1): 31-47. DOI: 10.1163/15707563-00002485
Flight initiation distance is defined as the distance between a prey and an approaching predator when the prey starts to flee. Escape theory predicts that the optimal flight initiation distance is the distance where predation risk rises to the point at which it equals the cost of fleeing. Therefore, staying close to refuge and occupying microhabitats with more abundant shelters (i.e., crevices or shrubs) may allow lizards to have shorter flight initiation distance. By simulating an approaching predator, we studied the effect of microhabitat structural complexity on escape behaviour, in particular, the distance fled before stopping and final distance (predator-prey distance when the prey stops fleeing), of a small diurnal tropical gecko, the yellow-headed gecko Gonatodes albogularis inhabiting a tropical dry forest. The findings indicate that refuge abundance and distance to the nearest potential refuge influence escape behaviour of G. albogularis. In addition, we found sex differences in escape behaviour which are not explained by microhabitat use. Females had longer flight initiation distance but shorter distance fled, and longer final distances than males.
Diego-Rasilla, F. J. , Luengo, R. M. & Phillips, J. B. (2015). Evidence of light-dependent magnetic compass orientation in urodele amphibian larvae. Behavioural Processes, 118: 1-7. http://dx.doi.org/10.1016/j.beproc.2015.05.007
Experiments were conducted to investigate whether larval palmate newts undertake orientation toward or away from the home shoreline (y-axis orientation) using the geomagnetic field to steer the most direct route, and if they accomplish this task through a light-dependent magnetoreception mechanism similar to that found in anuran tadpoles and adult newts. Larval palmate newts trained and then tested under full-spectrum light showed bimodal magnetic compass orientation that coincided with the magnetic direction of the trained y-axis. In contrast, larvae trained under long-wavelength (≥500 nm) light and then tested under full-spectrum light displayed bimodal orientation perpendicular to the trained y-axis direction. These results offer evidence for the use of magnetic compass cues in orienting urodele amphibian larvae, and provide additional support for the light-dependent magnetoreception mechanism since they are in complete agreement with earlier studies showing that the observed 90° shift in the direction of magnetic compass orientation under long-wavelength light (≥500 nm) is due to a direct effect of light on the underlying magnetoreception mechanism. This study is the first to provide evidence of a light-dependent magnetic compass in larval urodeles.