Animal rights charities are celebrating the news that increasing numbers of tour operators are ending "unethical" animal trips.
STA Travel, a global travel company that provides flights, accommodation and expeditions for 2.5 million students and young people each year, announced this week it had stopped selling elephant rides and tiger tours in Thailand.
The company also said it was "reviewing" tours of SeaWorld marine parks in Orlando and San Diego.
Meanwhile, adventure travel company Intrepid Travel has also reviewed the animal encounters it offers and has stopped selling elephant rides.
Intrepid, with its products available through travel agents or via its website, turned to the World Society for the Protection of Animals (WSPA) for advice on its animal tours.
Intrepid Travel co-founder Geoff Manchester believes tourism demand has led to venues where elephants, which are highly endangered, are forced to do "unnatural performances".
"The research concludes that this causes pain and suffering to the elephants, and that the tourism industry has added to the number of elephants being poached from the wild," he said.
Rather than offering elephant rides or entertainment venue visits, Intrepid is now working with rehabilitation and sanctuary facilities, he said.
WSPA's Dr Jan Schmidt-Burbach said wild animals belonged in the wild, not at entertainment venues.
"We welcome all progress within the tourism industry towards recognising this fact and taking action to prevent cruelty," he said.
Meanwhile, STA Travel called on People for the Ethical reatment of Animals (Peta) for their advice.
STA's social responsibility program manager Kathryn Kirkpatrick said the move to end the elephant and tiger encounters was the beginning of an effort to understand issues around ethical travel.
"This is the beginning of a lengthy process for STA Travel to ensure we are offering the very best possible range of experiences for our customers."
PETA believes marine parks deprive intelligent predators, such as orcas, that share intricate relationships and swim up to 100 miles a day, of a natural environment.
It also says elephant rides are cruel to the animals and dangerous for humans and that tigers become neurotic in captivity.