The spinning "I'm a pretty bird!" caged Military Macaw. Mistreated, high-intelligence parrots can quickly sustain irreversible mental damage, so the depiction is all too accurate of Real Life. Edges into Nightmare Fuel territory when one realizes a bird like that likely wouldn't survive long at all after being released into the wild...
In the sequel, we get this from Roberto, which only makes the implications worse...
Roberto: I know everything [about humans]. They lure you in...they trap you...they destroy your MIND! (suddenly starts twitching around) "Polly want a cracker? POLLY WANT A CACKER!?" NO! ENOUGH CRACKERS! (either terrified or on the verge of tears) I hate crackers!
Not necessarily. Blu and Jewel's offspring could be inter-bred with other compable species of bird to create fertile mix-breeds and eventually work back around to pure-breeding. Selective breeding can be used to save near-extinct species.
Confirmed averted in the sequel.
There's also the possibility that there are others of their kind scattered all over the world by smugglers. It would take significant legwork to gather them up, but that's how they got Blu and Jewel together.
Not quite, especially to someone who has worked with zoo animals (Education dept. intern). Animals are actually quite open to breeding with their immediate family members. In fact, that is the reason why some zoo animals have to be sterilized (like white tigers, all being siblings) to prevent accidental inbreeding.
In captivity. Most species strongly avert incest in natural conditions.
Nigel is full of this. The other birds seem quite terrified of him and he outright calls himself a "bird murderer". Any thens there's the above insane Military Macaw and the fact Nigel is the one who tortures the other birds (and he introduces himself by saying "I know I'm not a pretty bird" and uses the phrase quite a bit), it's quite unsettling to imagine just what he did to that poor bird...
Just the stress and prolonged caging would have been enough to Break the Cutie, as it often does in the real world; Nigel was just the black icing on that mud pie.
Nigel says a parakeet stole his spotlight, said parakeet being shown along with other relics of his stardom. If one looks closely at the birds in the smuggler's lair, you'll see a parakeet looking much like it is among the prisoners...
Nigel's Moral Event Horizon is forcing a little bird to pick a piece of chicken out of his beak. Already horrifying, but imagine putting yourself in that position: Since a chicken is also a bird, that would be the equivalent of picking apiece of human fleshfrom the mouth of avery largeperson.
Also, Nigel finds a poor little bird at the wrecked dance place. Suppose that poor bird really didn't know where Blu and Jewel went, and Nigel exploded the poor thing...
At the end of the Film, Nigel is revealed to still be alive, but shorn of most of his feathers. Bearing in mind he is unlikely to ask for or be offered any help to survive, doesn’t this mean he is going to suffer a slow, painful death from Starvation & Exposure? At least the propeller would have been quick...
He deserves it. He'll probably be eaten by some jungle predator anyway.
Blu miscalculated trying to break the chain with the rocks: the hanging rock is too large and would have crushed them both.
How far away from the Plane did Rafael, Nico & Pedro get before remembering that Blu couldn't fly?
The chain keeping Blu and Jewel together didn't break when the table saw hit it. They'd have both lost their legs at best or wound up macaw smoothies at worst.
Nigel is quite Dangerously Genre Savvy most of the time. This makes perfect sense as he used to be the hero in movies and television shows himself, meaning he's probably pretty well aware of tropes in such films.
Why are there costumes at Carnival modelled after Blu and Jewel? Simple. They got wind of Tulio's efforts to save the blue macaw species, and made the costumes as a tribute.
At the end of the film, why was Blu able to fly perfectly despite having never done it before & also carrying Jewel's weight? Its all those Vitamins Linda was sure to make him take.
When Tulio and Linda are dressed up in their blue Macaw costume, Tulio has one with tan eyes and Linda had one with blue eyes. Now, who are the Spix's Macaws that have the same eye colors as the "heads" that Tulip and Linda are wearing? Blu (Tulio) and Jewel (Linda). Yep, the birds and their caretakers are Expies of each other.