Want to see the world, and save it at the same time? Eco-minded travellers have ample opportunity to help threatened species and make a difference in scenic habitats in far flung corners of the planet. Here are five volunteer tourism spots that take animal encounters to a new level.

Snow leopards in Altai Republic
This off-the-beaten-track destination in Central Asia is surrounded by Kazakhstan, China and Mongolia. The views alone of the snow-capped Altai Mountains and open steppe in this Russian republic are worth the trip. But while marveling at the landscape, travellers can take part in two-week scientific expeditions to help study the endangered snow leopard. Travellers track the animals' movements and take stock of their prey, such as the argali (wild sheep) and ibex. Up to 12 people are guided by a scientist and a group leader from Biosphere Expeditions, a U.K.-based nonprofit, which helped obtain protected status for the snow leopard's habitat. Participants need to hike 1 to 9 miles a day and be comfortable living at a base camp, complete with shower tents, at 7,200ft above sea level. "If you want to access your inner scientist, this is the way to do it", says Stephanie Moreland, a Biosphere Expeditions publicist.

Lionfish prey in the Caribbean
Native of the Pacific seas, this red-and-white striped fish with long venomous spikes is an unwelcome sight in Atlantic waters. Rather than rescue this invasive species, certified divers can help save other species from the lionfish, a not-so-picky eater that has found a smorgasbord in the ocean. Lad Akins, director of operations for REEF (Reef Environmental Education Foundation) says researchers have found "over 50 different species of fish and many crustaceans" in the lionfish diet. And they have not found a predator willing to eat it. Likely introduced when a home aquarium broke during 1992's Hurricane Andrew, the Atlantic lionfish now number in the millions. Divers can help on REEF's week-long research trips, with 2011 destinations in Abaco and Belize. An aquarist with the National Aquarium in Washington, DC, also leads trips through a dive shop in Maryland. Volunteers are "critically important", says Akins. They help "collect specimens and the data... that just would not be available otherwise".

Frogs in Australia
It is not easy being a frog - in fact, species are declining at such alarming rates that US zoos declared 2008 the Year of the Frog to raise awareness. In Australia, several species have disappeared in the past 20 years and many more are critically endangered. Why? Scientists are not completely sure, though a deadly fungus poses a threat. For several years, Earthwatch Institute, a research and education conservation group, has organized weeklong professor-led expeditions for both adults and families to help figure out what is going on with the vanishing amphibians. Participants live in camping conditions in the forest and rainforest of eastern Australia, and much of the frog info-gathering is done after dark (when you can hear them). You can also make history; volunteers have played a part in identifying four new species of frog.

Sea turtles in Central America
"Save the sea turtle" may have been the first eco-tourism rallying cry on the planet. And these projects have never gone out of style. One reason: it is easy for volunteers to help out, for short or long stints. Another: watching baby turtles waddle their way into the water is amazing. Egg poaching, fishing nets and habitat loss harm the critically endangered leatherback (the largest reptile on earth) and the vulnerable olive ridley turtles. Opportunities in Costa Rica include organized tours with a few days of turtle duties or family fieldwork trips for parents with 10-year-olds to teens. Hang out for a month or more at Estación Las Tortugas on the Caribbean side, or head to Guatemala, where an interesting, if controversial, project has struck a bargain with poachers, who donate a portion of their finds to the researchers. Project Parlama - soon to be renamed Akazul - helps more olive ridley hatchlings survive than local laws alone would protect.

Whale sharks in Mozambique
Snorkeling above the largest fish in the world feels like being in a fairy tale. The whale shark (which is not a whale) can reach more than 40ft in length, but it gently glides along in the sea, scooping up plankton and posing no harm to humans. It is, however, a vulnerable species and volunteers can study the white-spotted, white-bellied goliath while staying in a beach house along the Indian Ocean in southern Mozambique- and earning their scuba certifications in the process. All Out Africa, a travel company and nonprofit foundation, offers four-week trips every month for up to 10 volunteers to work with the Foundation for the Protection of Marine Megafauna, photographing and monitoring whale sharks while snorkeling, and conducting coral reef and fish surveys below the sea.