As far as romantic rivals go, Dudard proves to be pretty non-threatening. He’s a university man—well educated and somewhat ambitious. Berenger sees him as a perfect candidate for a management position and as a likely match for Daisy. He turns out to be a likelier rhino, but that comes later
Despite his feelings for Daisy, Dudard’s actions towards Berenger seem to be pretty chummy. When Berenger is alone in his apartment, feeling afraid of the rhinoceroses and afraid that he might himself transform, Dudard is the first to check in on him.
In the apartment, the two delve into a lengthy debate about reason, free will, chance, and other serious subjects that French writers (even those born in Romania like Ionesco) seem pretty fond of. Berenger clings to the belief that transforming into a rhinoceros is not a choice. It’s just something that happens, like a sickness. Dudard, on the other hand, is convinced that those who have transformed have made the decision for themselves.
Dudard, like many in the play, holds reason in pretty high regard, and in the end he’s proven right. Once it’s clear that Daisy loves Berenger, Dudard makes the choice (see? He was right!) to join the rhinos.
He’s already weighed the options and he can see both sides of the argument. The Daisy thing, at least as Berenger sees it, is enough to push him to the other side. Before they can stop him, Dudard leaves Berenger and Daisy behind and goes to run with the herd.
Dudard proves to be an interesting character to deal with. While Jean’s transformation taps into the animal side of humanity and Daisy’s takes on a near-religious aspect, Dudard’s transformation remains highly intellectual throughout:
DUDARD: I shall keep my mind clear. [He starts to move around the stage in circles]. As clear as it ever was. But if you’re going to criticize, it’s better to do so from the inside. I’m not going to abandon them. I won’t abandon them. (3.1.790-793)
Ionesco gives us a glimpse into three very distinct transformations. Unlike Jean, Dudard never displays rage or animal instinct. Unlike Daisy, he doesn’t have some sort of religious-style epiphany. His choice is based on reason and made with a clear mind. It’s probably the most reasonable transformation into a giant leathery beast you could imagine.
These three transformations allow Ionesco to show that when a mass of people is converted to a single way of thought or a single action, it’s not just one type of person that buys in.