I saw this delightful piece on ScienceNews asking the tough questions:
Spoiler alert: the way that Dumbo is drawn (in the recent live-action remake and the original classic cartoon) would not allow Dumbo to get in flight.
An elephant’s ears are big. And they are muscled, so elephants can move them around. The animal can hold those ears out stiffly. But could those ears hold an elephant up? They’d have to be big. Very, very big. But wind speed can only provide so much lift. As a general rule, McGowan says, a bigger animal would need bigger wings. The wings would need to get longer and wider. But the animal’s body would also have a lot more volume. That means a big increase in mass. “If you increase a bird’s
size one unit, the [wing area increases] by one unit squared,” he says. “But the mass goes up by one unit cubed.”Wing size can’t increase fast enough to keep up with an increased body size. So birds can’t get very big. “It gets harder [to fly] the bigger you get,” McGowan explains. That, he notes, is why “you don’t see a lot of flying birds that weigh very much.”
There's a lot more in the article, including Giant Golden Moles (which I'd never heard of), flight ratios and more!