But his jaunt has thrown an unflattering spotlight on Africa's elephant hunting industry, which some argue is needed to keep swelling populations contained but critics see as an obscene pastime of the idle rich.

King Juan Carlos hobbled out of a Madrid hospital on Wednesday and apologised for making the elephant-hunting trip - one that caused outrage in a country suffering an economic crisis. The 74-year-old broke his hip and was flown back to Spain for emergency replacement surgery.

He is not reported to have bagged an elephant on this trip but Spanish media circulated a photograph of him in front of a dead elephant that apparently had been posted on a safari website and had been taken in 2006. The photo was later removed from the website.

Similar outrage greeted photos that went viral online of U.S. property magnate Donald Trump's sons with animals, including a Cape buffalo and a leopard, that they shot in Zimbabwe.

Many of the animals legally hunted in Africa as trophies are not highly endangered, or at least not in countries such as Botswana, South Africa and Zimbabwe, where such activities are permitted.

Take Botswana, the world's top diamond producer which is also rich in elephants.

According to a 2007 estimate by the African Elephant Specialist Group for the International Union for Conservation of Nature (IUCN) - regarded by scientists as the most authoritative - Botswana was home to at least 133,000 elephants but around 150,000 was given as the "probable" figure.

With a human population of 2 million, Botswana has the highest elephant-to-people ratio in Africa, at one for every 14 people.

Conservationists and hunters say their growing numbers are contributing to fewer forests and growing deserts.

"They have to cull them. That is the purpose of allowing people to hunt elephants," said Mike Cameron, a veteran South African professional hunting guide who has led many safaris to Botswana.

In areas around the Chobe National Park in northern Botswana "you can see the total decimation of the forest," he added.

But trophy hunting is putting little dent in Botswana's elephant population. According to the Convention on International Trade in Endangered Species (CITES), the treaty that regulates global wildlife trade, Botswana's export quota of trophy tusks has been 800 in recent years, or 400 dead elephants.

Hunting sources say the price of a two-week elephant hunt - including your kill and licence - costs $60,000 to $70,000 and usually excludes things such as charter flights to remote airstrips, so the final price tag can be much higher.

This is comparable to the cost of a guided climb to the summit of Everest, which can range from $35,000 to $100,000. Both bring money and employment to developing countries.

Animal welfare activists and other conservationists take issue with elephant hunting on grounds of cruelty, as the animals are highly intelligent with sophisticated social systems that scientists are still piecing together.

"Behavioural studies in Africa have shown that elephants are seriously impacted by activities such as hunting, culling and poaching, not only at the level of the individual animal, but at the societal level too," said Jason Bell, the elephant programme director for the International Fund for Animal Welfare.

(Editing by Giles Elgood)

• A Permanent Economic Emergency