NATURAL SELECTION IN ACTION 



371 



The most widely known example of mimicry in North America is that 

 of the Monarch and Viceroy butterflies. The striking similarity of these ac- 

 tually unrelated species is evident in Fig. 16.4. This is usually cited as an 

 example of Batesian mimicry, the Monarch being said to be inedible, the 

 Viceroy edible. This conclusion has been challenged, however, on the 

 ground that the Viceroy is also inedible. Brower (1958a) in an extensive 

 series of experiments with captive jays, found that the Monarch is indeed 

 unpalatable to these birds, and also that the birds do not distinguish be- 



FIG. 16.3. Mullerian mimicry: a moth which mimics a wasp. (Drawn 

 from a photograph in Beebe and Kenedy, "Habits, palatability and 

 mimicry in thirteen Ctenuchid moth species from Trinidad, B.W.I." 

 Zoologica, Vol. 42, 1957, pp. 147-158, Plate II.) 



tween the Monarch and the Viceroy. Thus birds that had learned to avoid 

 the Monarch also avoided the Viceroy. Brower found that birds which had 

 not been given experience with Monarchs ate Viceroys but that on the 

 whole Viceroys seemed to be less palatable than were other species of 

 butterflies tested (e.g.. Tiger Swallowtails). Hence this example seems to 

 fall somewhere between classical Batesian and classical Miillerian 

 mimicry. 



Brower (1958b) tested other cases of mimicry with her captive jays. She 

 demonstrated one example of classical Batesian mimicry. The butterfly 

 Battus philenor was unpalatable to the birds; having had experience with 



