Viceroy

"The viceroy's major defense against predators is purported to be mimicry. It had been long accepted that the viceroy practiced Batesian mimicry, with the monarch and the queen serving as models. Batesian mimicry is a type of defensive behavior in which a palatable species closely resembles unpalatable or toxic species to avoid predation. As such, the viceroy's wing color ranges from tawny orange (resembling monarchs) in the north to dark mahogany (resembling queens) in the south...It has been argued that selective pressures from predators have given rise to "model switching" in the viceroy, with each subspecies choosing to copy the color pattern of the locally dominant Danaine subspecies. When the monarch's breeding range overlaps with the viceroy, the viceroy will adopt the lighter shades of orange. Towards the south, the viceroy mostly displayed darker orange phenotypes in response to the larger population of queens...Recent research has argued that the viceroy may be unpalatable to avian predators. If that is the case, then the viceroy butterfly displays Müllerian mimicry, and both viceroy and monarch are co-mimics of each other." - Wikipedia