Roger Gower was working with Tanzanian wildlife authorities when the poachers fired on his helicopter and fatally wounded him Friday, said Dan Friedkin, chairman of the Texas-based non-profit Friedkin Conservation Fund
"We are profoundly saddened by the loss of our dear friend," he said.
Gower managed to land the chopper but died before he was able to be rescued, said Lazaro Nyalandu, the country's former tourism minister, who said he flew with Gower many times.
Gower was helping rangers find the killers of an elephant when the poachers fired at the helicopter with an AK-47, Nyalandu wrote on Twitter.
Photos of the crash site, provided by Tanzania National Parks, show the helicopter on its side in dense grass, its tail broken off. A bloody bullet hole can be seen in one of the seats.
"Those poachers who killed Capt Roger are coward, evil, and sad people. A fine hearted individual gone too soon, and our hearts are broken," Nyalandu wrote.
The shooting happened at the Maswa Game Reserve, which borders the Serengeti National Park in northern Tanzania, Nyalandu said. Elephant poaching is prevalent on the reserve, according to the Friedkin Conservation Fund.
It was not immediately clear whether Gower was working for the fund when he was killed.
"This tragic event again highlights the appalling risk and cost of protecting Tanzania's wildlife," Friedkin said.
The killers are still at large, Nyalandu said. Tourism Minister Jumanne Maghembe flew to Maswa with senior government officials to lead the search, he said.
"Capt Roger represented the very best in human spirit," Nyalandu wrote. "He loved people and the wildlife. He died serving both."