I know it´s horrible to see a population erased by loss of habitat, but i hardly find that to be an excuse to catch wild native fauna. It´s far far better to "move" the animals to a close but suitable area(as close as possible).
Breeding to repopulate might sound like a noble idea but it´s actually a pretty bad one.
First off, if the habitat has been lost(after all that´s why you caught them, right?), then repopulating makes no sense at all.
Secondly, and this is also a very important point, releasing animals back into the wild should NEVER be done by individual hobbyists. The risk os introducing patogens(bacteria, fungae, parasites...) into the wild is very real, and is reason enough to make releasing a very bad idea.
Also if you were to release animals into a different area, there´s also the problem of contaminating local genetic pools. By introducing new genetics you might destroy a particular blood line.
Releasing is therefor something that should be done only by the pertinent organisms, and with the utmost care and knowledge of what one is doing.