During the time when the passenger pigeon was hunted down to only captives in the zoo, how could the zoo not maintain a small population and keep the species alive? Why did the population slowly die out? I thought a bird can successfully raise multiple young, given the near perfect conditions in captivity in which the people there are trying to keep them alive?
Just a question I ramdomly thought of, so answers would be appreciated! Edit: this is not a duplicate. Birds can have multiple young. That will increase the population success rate.