OK, so maybe I missed this, but was it established that Charles Muntz would harm Kevin (the bird)? It seemed to me, if he brought her (and perhaps the chicks) alive to prove his point no big harm would come to her (aside from being outside her natural habitat, I guess...)?
I think the concern was that Kevin's absence from the island would likely leave her babies to die. Muntz had already stated his belief that going to where the babies were was a death trap, and Muntz wasn't going to give up the bird; so the babies would have been left on their own.
I loved the movie, but I think I'm getting too old for these films, because I kept thinking about things I never should have bothered with in a movie where a house tied to balloons flies from New York to South America in the span of an old man being knocked unconscious. For instance, I kept wondering why Muntz couldn't just come back and say, "I invented a method to allow dogs to talk, cook food, and fly planes." Seems a tad more impressive than just finding a bird. He could also share his amazing rejuvenation techniques. It's a remarkably poignant film in parts, though.
Well the best case scenario there is Kevin gets stuck in a tiny cage for the rest of her life surrounded by loud people. Worst case scenario he kills Kevin to make sure she doesn't escape. Didn't he decide to just kill her at the end of the movie?
Muntz was obsessed, as many such people are. His plans for Kevin, short of a full habitat transplant, would have been no good for her, and even that would be questionable. My big question is, just how old was this guy, who was an adult hero when Carl and Ellie were not even teens? I still seriously loved this film. Consider me first in line for the deva-d.
If Muntz was in his 20s or even 30s when he was a hero to Carl and Ellie, and Carl is in his 60s during the bulk of this film's plot -40 years after the begining of the film- that would put Muntz in his 60s or 70s. Hell, even if Carl is in his 70s that'd only make Muntz in his 70s or 80s. He's also been living on an island, eating natural foods and not been exposed to pollutants and other potential toxins. So it's reasonable that he'd be within a human life-span and also in good health.
Without the bird though, he'd still have a tarnished reputation as "the guy that lied about the bird," and that's all that mattered to him.
Yes, but it was his reputation at stake, you see. That trumps other concerns, like practicality or reason. In response to the OP, I'm not convinced that Muntz didn't have sinister plans for Kevin, considering he apparently murdered the last half-dozen or so humans to stumble on him in the jungle. He'd probably dissect her and stuff and mount the remains so his amazing discovery could last forever. Or, to put it another way, would you trust a clearly unstable man with the only known living specimen of an animal that he's been so obsessed with he went mad?
^Plus, the fact that all his other collected "specimens" were mere skeletons was kind of a clue that the bird's well-being was not high on his list of priorities.