One of the few true frugivores (fruit feeders) among birds, the cedar waxwing can assimilate nutrients solely from fruit—low in calories and protein compared with insects—for weeks at a time. Toyon berries are technically pomes, like apples, and their seeds contain similar toxins. Green toyon berries are loaded with poisonous cyanogenic glycosides, but as they mature, their toxins shift from pulp to seed and the berries turn red, signaling their edibility.
Waxwings safely pass the toxic seeds through their guts and back into the environment intact, in the process dispersing toyons to new areas.