In some of Heade’s hummingbird battles, the female is present on or near a nest. That is, the female has already made her choice, and, in the Darwinian explanation, male combat is no longer necessary. Yet, Heade’s bellicose “mutton chops” fight on.

As travelers from the United States were learning, the neotropical wilds could be deadly as well as exotic, and Heade’s hummingbird paintings introduced the issue of scale to the magnitude of danger. Secondly, they raised the question of the human place in nature. In the Descent of Man, Darwin recounted an incident between two male hummingbirds in captivity. One would have killed the other “had not the observer interfered, the female [bird] all the time looking on as a quiet spectator.”1 Thirdly, Heade’s pictures compared sexual selection and artistic taste. Did Heade intend the human viewers of his pictures to assume the roles of these silent, but choosy, spectators, who in the end select the winners to suit their fancies? If so, he was advocating a bold new museum esthetics of sexual wager.

Heade’s survival as a painter required discerning spectators to admire and buy his pictures. By contrast, the survival of his double, Didymus, required the “necessity of virtue” and a selective, but changing, audience to read and respond to his letters. Heade the artist painted displays of male combat among hummingbirds; Didymus the critic condemned trophy hunting as a display of male combat with no purpose.