The U.S. Fish and Wildlife Service said on Thursday that it was investigating the circumstances surrounding the killing of Cecil, a lion who is thought to have been lured out of his protected habitat in Zimbabwe this month and killed by Walter J. Palmer, an American dentist and hunter.
“That investigation will take us wherever the facts lead,” said Edward Grace, deputy chief of law enforcement at the agency. “At this point in time, however, multiple efforts to contact Dr. Walter Palmer have been unsuccessful.”
The killing of Cecil became a global subject of outrage this week, and Dr. Palmer, who has said that he believed the killing of the animal was legal, has been the target of a vociferous Internet shaming campaign.
The lion, well known to those who visited Hwange National Park in western Zimbabwe and by many locals, was killed and beheaded — the head intended as a trophy for the hunter.
Wildlife officials and conservationists say some big-game hunters in search of exotic trophies and poachers who cross into protected parks and other habitats to slice the tusks off elephants and chop the horns off rhinoceroses, leaving the animals to die, are causing a global crisis.
Citing what it called alarming trends in illicit hunting and poaching, the United Nations General Assembly adopted a resolution Thursday that supporters say would be the start of a global effort to tackle illegal poaching and trafficking of wildlife.
In an address to the General Assembly, Harald Braun, the permanent representative of Germany to the United Nations, said that illicit hunting had become a pressing global issue. He described the poaching of an elephant for its tusks near a national park in South Africa this week, and the killings of over 700 rhinoceroses for their horns in South Africa so far this year.
“The time to act is now,” Mr. Braun said. “No one country, region or agency working alone will be able to succeed.”
United Nations officials said that the resolution would foster cooperation among countries to fight money laundering, and that Secretary General Ban Ki-moon would recommend actions based on the resolution next year.
Public attention to poaching, often carried out by criminal gangs and cartels seeking ivory and horns, has increased, officials say. This week, in addition to the elephant killed around Kruger National Park in South Africa, five elephants — an adult female and four of her calves — were killed for their tusks at a park in Kenya.
President Obama made tightening the ivory trade a key point of his visit to Kenya last weekend. He announced changes that would effectively ban the commercial trade of African elephant ivory in the United States in an effort to further close loopholes exploited by traffickers.
According to the Wildlife Conservation Society, the global ivory trade drives the killing of as many as 35,000 elephants a year across the continent. In 2012, The New York Times reported on rhinoceros poaching, finding that horns were traded at $30,000 per pound, making them more valuable than gold. Illegal trafficking is estimated to bring in at least $10 billion worth of stolen animal and plant products a year, with most customers in Asia and North America, United Nations officials said in a statement Thursday.
Leigh Henry of the World Wildlife Fund said the resolution sent a “powerful message from the highest possible level” about what many feel is a growing criminal threat to wildlife.
Cecil had been closely watched by researchers at the University of Oxford since 2008 as part of efforts to study a decline in Africa’s lion population and the threats the animals face.
David Macdonald, the founder of the university’s Wildlife Conservation Research Unit, recalled that a brother of Cecil’s, called Jericho, had once been ensnared by wires that are commonly used to trap lions, but said it was likely that the trap had been set by locals seeking other bushmeat. Jericho was freed from the wire.
Illegal poaching is just one threat facing the greater habitat of the lions, Professor Macdonald said. Lions that attack the cattle and sheep of local ranchers are often killed.
Donations to Professor Macdonald’s organization, which tracks about 30 lions, have surged since Cecil’s killing was widely publicized.
“The attention on the single animal might be sort of a barometer of people’s concern,” Professor Macdonald said. “But what I would like is if people see this in the wider landscape.”
An earlier version of this article misidentified one of the two continents where most of the customers for illegally trafficked animal parts are located. Besides North America, the continent is Asia, not Africa.