It's a whole new week, so I'm moving away from the artiodactyl theme (for now, at least) and the PotD will probably take on a more random aspect for a while. Today's photo is of the tiger cubs Terney (center, with tire), Changbai (left), and Koosaka (right), born at the Philadelphia Zoo a few months ago. They are Amur (or Siberian) tigers, Panthera tigris altaica, the largest of the extant tigers and also critically endangered. While the zoo notes that they contribute to tiger conservation initiatives like the Tiger Conservation Fund, it seems that these cubs will remain in captivity and there seems to be no active breeding program with the goal of release into the wild active at the Philadelphia Zoo.
I was under the impression that tigers, and most animals for that matter, hardly ever, as in almost 0 percent of the time, breed successfully in captivity.
Ben Hardisty, you haven't been to many good zoos lately. For many endangered and threatened species, there are Species Survival Plans so that the animals can be not only bred, but bred with a proper mix of genes for maximum diversity. That's why animals (or their semen) are moved from zoo to zoo on breeding loan. A lot has been learned about each species' breeding requirements in recent decades. For info on SSPs see http://www.aza.org/ConScience/ConScienceSSPFact/ and for info on (as an example) 18 panda cubs born at Wolong Reserve in China in 2006, see http://www.chinadaily.com.cn/photo/2007-01/25/content_792519.htm
Thanks for the comments Ben and Tina. Some animals are still difficult to breed in captivity, Ben, but there has been much success in recent years. Much of it has to do with updates in technology and changes in zoos; the concrete pens ringed with iron bars of the past were not very conducive to breeding. In fact, it seems that the larger battle in the past was keeping the infants alive once they had been born. Artifical Insemination has also been a big help when doing it "the old fashioned way" doesn't work. Pandas are probably the biggest success story, but big cats like lions, tigers, and leopards have had a much longer success record.
From what I can tell from the AZA site, though, most of this breeding is done to keep the animals in the zoos, the animals that are returned to the wild usually being ones endemic to the country which the zoo is in. Such programs might keep the species "alive" in captivity, but unless it is matched (or even exceeded) by conservation programs for wild stocks we could still lose the remaining populations of some animals. Indeed, my own standpoint is that when all the orangutans are gone in the wild, for instance, we have lost the orangutan no matter how many are alive in zoos. There are some zoos that are truly committed to conservation, however, the WCS (which runs the major zoos and aquaria in New York) being a good example of an organization running good zoos and working for conservation of wild groups.