Charitable donations to help protect an endangered species are one thing. But would you don a piece of permanent body art to save a mammal, plant or even a fungi? Three years ago, 100 men and women in the U.K.—average people, not scientists—did just that. Each of them went under the needle to get a tattoo of a species they vowed to help protect. A traveling exhibition that lauds these inked advocates will soon come to a close, but the project may spawn broader outreach efforts.

The project, called extInked, was conceived by the Ultimate Holding Company in Manchester, England—a collective of freelance artists who try to use art to spur discussion of uncomfortable social issues. In 2009 the collective worked with conservationists to identify 100 rare and endangered species in Britain, and then brought in artists to ink 100 volunteers in a three-day public marathon. Mammals, amphibians, reptiles, birds, fish, invertebrates, plants and four species of fungi were colored onto the necks, arms, legs and backs of obliging “ambassadors.”

» View a slide show depicting eight volunteers and their tattooed species

Since then, the volunteers have given talks at meetings, distributed literature, raised funds with conservation groups, appeared at exhibitions and taken on other activist roles related to their adopted species. “The ambassadors have brought together the art world, the ecology world, the science world and the tattoo world,” says Kate Houlton, a project manager at Ultimate Holding. “The project has been a creative way to encourage conversation.” People from as far afield as Canada, Brazil and South Korea have taken up causes after seeing or reading about the tattooed ambassadors, Houlton says.

The exhibition, which features professional photographs of all 100 volunteers and their tattoos as well as information about their species, is making its final stop at the Rugby Art Gallery & Museum in Rugby, England. That show is set to close on November 10, but other galleries are now interested in resuming the tour, Houlton says. Ultimate Holding is also seeking collaborating organizations in other countries that could kick off similar projects.

The extInked project might be inspiring independent efforts, too. One group in California’s Bay Area, called Tatzoo, has held several boot camps to train volunteers to become conservation leaders for local fauna and flora. Graduates receive a certificate and a tattoo of the endangered species of their choice.

» View a slide show depicting eight volunteers and their tattooed species