Fig. 4: Monarch light-dependent magnetoreception involves both the antennae and the compound eyes.

Magnetic responses of wild-type monarchs with black (black bars) and clear (white bars) painted antennae a or eyes b to a reversal of magnetic inclination (RAMI; red line) under different lighting conditions (full spectrum, white circle; darkness, black circle; UV-A/blue, violet circle; cyan/green, green circle). c Magnetic responses of wild-type monarchs with one antenna and one eye painted black (black bars) to a RAMI (red line) under full-spectrum light. Monarchs with clear painted antennae and eyes (white bars) were used as controls. Each box plot shows the number of wingbeats for every 10 s time bin (median, centerline; interquartile range (IQR), box; 1.5× IQR, whiskers). Each dot represents the response of an individual (n = 18 for each painting group). Statistical significance between painting groups was tested for each time bin using a two-tailed Mann–Whitney U test at p < 0.05 (Full spectrum in (a): ^* p = 0.019 and p = 0.029 for third and fourth 10 s time bins respectively; UV-A/blue in (a): ^* p = 0.029 and p = 0.017 for third and fourth 10 s time bins, respectively; Full spectrum in (b): ^* p = 0.016 for fourth 10 s time bin and ^**p = 0.009 for third 10 s time bin; UV-A/blue in (b): ^* p = 0.011 and p = 0.027 for third and fourth 10 s time bins, respectively). Transcript (d) and protein (e) expression levels of dpCRY1 in antennae (Ant), compound eye photoreceptors (Eye PR), and optic lobe (OL) of adult monarchs (n = 6 per tissue in (d)). d Data are presented as mean values ± SEM.