The terms charismatic megafauna and flagship species are often used interchangeably, and generally describe a species that functions as an ambassador or symbol for a particular habitat or cause. These may or may not also be keystone species, which perform an important or essential role in the ecosystem or habitat in question (such as the role of the bee in pollination). An indicator species is a bellwether of what's going on in a given ecosystem (for instance, a declining crayfish population is an indicator of that a freshwater supply is polluted) [source: World Wide Fund for Nature].
Charismatic megafauna as tools for conservation promotion works because we as humans seem hardwired to prioritize the interests of attractive animals. One University of Arizona study found that people are more likely to support preservation efforts of animals that are attractive and resemble humans — study participants preferred flyers with an image of an ape over that of a bat. Another study showed that women, in particular, are more inclined to appreciate and sympathize with loveable animals, as opposed to "fear-relevant" animals, like reptiles, amphibians and insects [source: Schlegel].
Shallow though it might seem, a number of animals have already benefited from the charismatic megafauna label. Bald eagles, a symbol of the United States, were the poster species for the anti-pesticide (specifically, DDT) movement of the 1960s and '70s. Since then, their numbers have recovered so significantly that the United States Fish and Wildlife Service removed them from the endangered species list.
Elephants are another work-in-progress story. Although illegal poaching of a number of species remains a tragic threat, elephants have often fronted international anti-poaching campaigns and regulations, which impact more than 35,000 species including these gentle giants, as well as tigers, rhinos and sharks [source: McCarthy].
The ever-popular giant panda has enjoyed a 17 percent wild population increase over the past decade, largely due to massive conservation and captive breeding efforts. In fact, the species recently made headlines when the International Union for Conservation of Nature changed its status from "endangered" to "vulnerable." A panda famously fronts the logo of the World Wildlife Fund, arguably the biggest organizational champion of conservation issues in the world.
Of course, charismatic megafauna remain popular attractions at zoos and aquariums, and are likely to continue to function as "spokes-species" for the foreseeable future. This is as much for their own good as the good of those other animals they protect. "Zoos are also incredibly important to the survival of charismatic megafauna," Braccini explains. "Many of these species are not safe in their natural habitats due to hunting, poaching and/or habitat loss, and the survival of the species may come down to the maintained population within accredited zoos and aquariums."