New calf brings new hope, and new concerns, for embattled Sumatran rhinos

Inbreeding isn't bad, per se. I don't have the reference now, but it has been shown that small populations can (not guaranteed) facilitate species survival by weeding out deleterious mutations. A sub-population founded from a small population is typically more robust than a sub-population of the same size founded from a large population, as the deleterious mutations have been weeded out.

The diversity that's really important for long-term population survival is immune system diversity.

So basically, for species threatened with extinction, it would be more important to remove deleterious mutations than to increase genetic diversity. And possibly also raise the new generation separate, in case the species act like humans and are less likely to mate with those they've grown up with.

> Because all those hungry sailors were part of colonialism anyway and should have known to starve themselves!

They were in no danger of starvation. They hunted dodos and dodo eggs because it was easy to do so.

> primitive enough to be wracked with guilt over other animals dying, but only the cute or beneficial ones.

It's part of the same impulse that encourages us to take care of children, even those children not related to us. And plenty of people feel it for the non-cute animals as well.