With the Duke and Duchess of Cambridge set to visit the world's largest one-horn rhino park in remote northeastern India, conservationists hope the British royals can help raise global alarms about how black-market demand for rhino horns and other animal parts is fueling illegal poaching and pushing species to the brink.

But just days before their Tuesday arrival, park officials said yet another rhino had been poached, bringing the total number of rhinos killed in Kaziranga National Park this year to six.

Poachers shot the rhinoceros and, while it was still alive, sawed off its horn before fleeing before dawn Sunday, wildlife official Subasis Das said. Once the dying animal was discovered, park officials rushed to try to save it but were unsuccessful, he said.

Prince William and his wife, Catherine planned a visit to Kaziranga specifically to focus global attention on conservation. The 480-square-kilometer (185-square-mile) grassland park is home to the world's largest population of rare, one-horned rhinos as well as other endangered species including swamp deer and the Hoolock gibbon.

The park has overseen major conservation success, with its rhino population increasing from just 75 in 1905 to 2,200 last year. Many give credit to Lady Mary Curzon, a British baroness who reportedly persuaded her husband, Lord George Curzon, to take steps to protect the rhino when he was governor general and viceroy of India in 1899-1905 when it was still part of the British Empire.

"The Royals should focus on global awareness and the success of Kaziranga, a conservation story started by Lady Curzon," said industrialist Ranjit Borthakur, who heads the Balipara Foundation conservation group in the state of Assam.

But as the neighboring human settlements continue to expand, the animals find themselves in increasingly tense competition for habitat.

All five of the world's rhino species are under constant threat from poachers seeking their horns to sell on the black market. Demand is high in countries such as China and Vietnam, where people mistakenly believe consuming rhino horns can increase male potency. It does not.

Already six rhinos have been poached this year, after 20 were killed in 2015.

"The Duke will use this visit to speak out against the lies and violence that threaten this valuable species and the communities that rely on it," Buckingham Palace said in a statement. "Traffickers in South East Asia are now marketing Indian rhino horn as 'fire horn' and lying about its increased potency when compared to African horn."

Conservationists say the royal visit couldn't be coming soon enough.

"The British royals' visit will certainly increase the level of awareness on rhino conservation," said Bibhab Kumar Talukdar, who heads the local wildlife protection group Aaranyak. He wants the royals to press China and other countries to curb consumption of rare animal parts, including rhino horns as well as tiger bones and pangolin scales.

"We would expect the Duke and the Duchess to convince them to clamp down on such use," Talukdar said.

The royals are expected to arrive Tuesday evening in the garrison town of Tezpur, in the northeast Indian state of Assam. From there they will travel to an exclusive, 12-cottage jungle resort with thatch rooftops overlooking fields and a river, according to local officials who spoke on customary condition of anonymity.

During a two-day stay, they will meet rangers and take a jeep safari through the park. They will also speak with Karbi tribal villagers who live in a nearby hamlet — a meeting that is expected to boost morale among locals trying to protect the area's wildlife.

"The royals' visit will bring Kaziranga further into the limelight. The villagers around the park will get added encouragement to work harder," said Anowaruddin Choudhury of the Rhino Foundation for Nature in Northeast India.

After visiting the park, the couple will fly to the neighboring kingdom of Bhutan on Thursday morning.