In a bid to end decades of worsening human-elephant conflicts, Thai authorities are pushing ahead with a plan to sterilise wild elephants using vaccine shots.
Since 2012, at least 240 people have been killed and 208 others injured in conflicts as the massive creatures stray out of forests in increasing numbers to forage in farmland and communities that continue to encroach on their wild habitats.
However, the sterilisation plan has sparked growing concern among environmentalists and animal rights activists.
“I don’t think it will reduce the number of wild elephants straying out of forest zones," said Theerapat Trungprakan, president of the Thai Elephant Alliance.
Kanchana Silapa-archa, chief advisor to the Chart Thai Pattana Party, said she was shocked to learn the government is set to sterilise wild elephants and questioned whether the move is backed by solid research.
Background to the conflicts
Thailand is home to between 4,013 and 4,422 wild elephants across 16 forest zones, according to the Department of National Parks, Wildlife and Plant Conservation (DNP).
Five of these zones are experiencing severe human-elephant conflicts, with pachyderms regularly wandering out of their habitats and damaging crops and properties.
The clashes with humans have also turned deadly, with casualties on both sides.
On April 5, 2023, the national Elephant Conservation and Management Committee approved the following six measures to address the problem of human-elephant conflicts:
• Expanding forestland
• Building more buffer zones
• Forming wild-elephant monitoring teams
• Providing support for communities affected by the conflicts
• Implementing sustainable management of elephant habitat
• Controlling the wild elephant population
“With the annual birthrate at 7-8%, the wild elephant population could surge to 6,000 in the next four years if we do not take action,” warned Natural
Resources and Environment Minister Chalermchai Sri-on.
He said the DNP had begun trialling the sterilisation vaccine this month, aiming to maintain the elephant population at levels that allowed sustainable coexistence with humans.
“The programme will be piloted in eastern forests first. If the results are satisfactory, we will expand it to other regions,” the minister said.
Chalermchai reported that eight people had been killed and five injured by elephants in Thailand during the fourth quarter of 2024 alone.
“Data from 2018 shows that human-elephant conflicts result in an average of one human death every nine days,” he added.
Elephants also fall victim to the conflicts. Between 2012 and 2024, at least 195 wild elephants have been killed by shooting, electrocution, vehicles, or animal traps.
SpayVac: The chosen vaccine
DNP director-general Atthaphon Charoenchansa said his agency had collaborated with Chiang Mai University’s veterinary team in a 12-month study of the SpayVac vaccine to be used in the elephant sterilisation programme.
Developed by the US Department of Agriculture, SpayVac is designed to control populations of wild and feral animals without the need for surgical sterilisation.
It works by blocking the release of fertility hormones. Produced by US company American Vaccination Inc, SpayVac costs $250 per dose.
It has already been used on African elephants and found to be effective for up to seven years after vaccination.
“We vaccinated seven domesticated female elephants in April last year and monitored their condition. So far, the vaccine has proved to be safe and effective,” Atthaphon said.
The monitored elephants have shown no signs of side effects or behavioural changes.
SpayVac has been used to sterilise various wild animal species, including African elephants, deer and seals, explained Assoc Prof Chatchote Thitaram of the Elephant and Wildlife Health Centre at Chiang Mai University’s Veterinary Faculty.
“We can assure you that vaccination [with SpayVac] does not constitute animal cruelty,” he said.
The sterilisation effort is far more humane than the radical approach used to control African elephants in the past, he noted.
From the 1960s to the 1990s, South African wildlife officials used helicopters to cull wild elephants, herding them into tight packs so they could be shot dead by hunters.
Boripat Siri-aroonrat, president of the Zoo and Wildlife Veterinarian Association of Thailand, observed that culling is still used in many countries to control wildlife populations.
“However, Thailand has shunned this practice,” when it comes to elephants, he said.
He added that sterilisation would not significantly reduce the wild elephant population, let alone eradicate them from Thailand’s eastern forest range, as some critics have suggested.
“We only want to ensure that the number of wild elephants matches the resources in the forests,” said Boripat, who is also a veterinarian.
Atthaphon said the eastern forests were currently home to 592 elephants, far exceeding their capacity of 323. He added that only 20 elephants would be sterilised in the east.
More solutions needed?
Suwichan Suwannaka, who represents victims of human-elephant conflicts in the eastern province of Chanthaburi, reckons the wild elephant population is expanding rapidly due to the absence of large predators.
“I agree with the move to control wild elephants’ birthrate,” he said.
But Suwichan wants the government to do more, including the construction of fences to ensure wild elephants remain neighbours instead of habitually straying into human communities.
“Also, we hope the government will provide compensation for crops damaged and people killed or injured by wild elephants,” he said.
Vaccine’s safety questioned
Andaman Adana, a representative of the Fight for Elephants Network, said the DNP had been too hasty in declaring the vaccine safe during its experiment with seven domesticated female elephants.
“If the vaccine is effective for seven years, you should gather data [from the sterilised elephants] over seven years,” she said.
She also questioned whether the DNP would be accountable if the vaccination programme ended up harming wild elephants.
Theerapat, of the Thai Elephant Alliance, added that full findings from the vaccination study on female elephants should be made public.
“I heard that there is no bull elephant within range of the vaccinated females. So, how can they be sure the vaccinated elephants won’t get pregnant?” he asked.
Theerapat also pointed out that elephants should not be considered invaders, given that they roamed freely across the plains for centuries before their habitat was encroached upon by humans.
“Don’t think that elephants love densely forested uplands and should just stay there. In fact, they are perfectly at home on flat grassland,” he said.
