- Author: Kathy Keatley Garvey
The shadow knows, but what does it know?
It knows to follow.
It follows the Gulf Fritillary--a brightly colored orange and black butterfly with silver-spangled wings--up a fence in Vacaville, Calif., and vanishes.
That's what butterflies and shadows do--they vanish.
If you're growing passionflower vine (Passiflora), you've probably photographed the Agraulis vanillae egg, the caterpillar, the chrysalis and the adult.
But its shadow?
Have you photographed its shadow, that dark silhouette intercepting rays of light?
The shadow knows, but what does it know?
It knows to follow.
![The Gulf Fritillary, a brightly colored orange and black butterfly, casts a distinctive shadow. (Photo by Kathy Keatley Garvey) The Gulf Fritillary, a brightly colored orange and black butterfly, casts a distinctive shadow. (Photo by Kathy Keatley Garvey)](https://ucanr.edu/blogs/bugsquad/blogfiles/102587.jpg)
![Up and away...the butterfly and the shadow begin to vanish. (Photo by Kathy Keatley Garvey) Up and away...the butterfly and the shadow begin to vanish. (Photo by Kathy Keatley Garvey)](https://ucanr.edu/blogs/bugsquad/blogfiles/102588.jpg)