According to the findings of the study published in January 27 issue of the journal Neuron, migratory monarch butterfly use skylight cues and an internal compass to navigate from eastern North America to Mexico every fall. Study conducted earlier have shown that these migratory birds use a time-compensated “sun compass” to keep moving towards the southern direction.

“In general, this sun compass mechanism proposes that skylight cues providing directional information are sensed by the eyes and that this sensory information is then transmitted to a sun compass system in the brain,” explains senior study author, Dr. Steven Reppert from the University of Massachusetts Medical School.

“There information from both eyes is integrated and time compensated for the sun’s movement by a circadian clock so that flight direction is constantly adjusted to maintain a southerly bearing over the day.”

“Our results reveal the general layout of the neuronal machinery for sun compass navigation in the monarch brain and provide insights into a possible mechanism of integrating polarized skylight information and solar azimuth, “said the authors.

“More generally, our results address a fundamental problem of sensory processing by showing how seemingl,y contradictory skylight signals are integrated into a consistent, neural representation of the environment.”