Donors. They want something that makes them feel good. Something to talk about at a cocktail party. LCM: large charismatic mammal; I'm saving pandas is better than the parasitic anderson wasp* that lives out its lifecycle in some gross fungus thing

*imaginary bug

Your point is well taken that pandas are probably a quick pitch for the right crowd, but “lots of money” seems optimistic for wildlife/conservation biology funding. That said, raising money for diseases of __human__ inhabitants of the developing world is typically quite a challenge. Counter to the focus of this thread, obesity is where it’s at right now for abundant funding.

It comes down to a lot of factors, but a big one is the diversity of funding sources. If you study a species that doesn't have broad appeal, you're probably looking at NSF funding, maybe USDA. If you study a game animal you can tap into all sorts of funding sources, like Ducks Unlimited, etc. You might be able to get state or federal wildlife agency funding. You might get a weird, wealthy donor who like sharks.

NSF grants are still the most important and impressive for most subfields within ecology, but the competition is fierce.