Stephanie Hanes, for the Pulitzer Center
Gorongosa, Mozambique

Hi. I realize there have been a couple of questions about animal reintroductions, and I haven't really answered those yet.

The whole question about how to bring animals back to the park has been the focus of a lot of research and analysis. See, ecosystems are super complicated. Every species has a role to play, and each animal impacts every other animal. So the park staff has to be really careful.

Take, for instance, the Gorongosa herbivores. Once upon a time, the park's herds of buffalo, zebra and wildebeest were huge – among the densest in Africa. (By the way, wildebeests are funky looking antelopes that live here – also known as the "gnu.") But the park staff can't just toss a bunch of these animals back in the park and assume they'll survive.

The herbivores used to work together. The hippos would trample paths in the tall grasses, which would make it easier for other animals to come in and graze. Some herbivores would munch on the tall grasses, which would clear up the shorter grasses for other antelope. And so on. So the park needs to get the order right – no point in introducing the short-grass loving animals until the tall-grass eating animals are well established.

Then there's the whole issue of logistics. Where do you find a bunch of zebra for sale? Lots of places in southern Africa, actually. But the park needs to make sure that they're getting the right kind of zebra – healthy zebra, the correct genetic type of zebra, etc. Once they've got this figured out, then they need to arrange a way to transport the animals. Last year I watched them load up a bunch of buffalo (ornery animals) from South Africa's Kruger Park – it's quite a complicated process.

Then, at Gorongosa, they need to put the animals into a sanctuary - if they just dropped them in the wider park, the lions would have a field day. (There aren't many lions left, but enough to do some damage to a freaked-out herd of wildebeest.) Then it's a process of moving them from smaller areas to larger areas, and then into the park itself.

There are other issues, too. Take poaching. With an animal sanctuary, the park is basically advertising to poachers that, hey, there are going to be a lot of animals right here. So they need to make sure their law enforcement is going strong.

This isn't everything, but at least gives you a sense of the complexity...