Zookeepers kill healthy baby giraffe with a bolt gun because he was ‘surplus to requirements’ and then feed him to the lions but not before doing an autopsy in front of young children. He was 2 years old. Marius was not fully grown. He could have grown another three feet or so.

Despite more than 20,000 people signed an online petition to save two-year-old Marius, staff at Copenhagen Zoo went ahead and shot the animal with a bolt pistol.

The Danish zoo said the drastic move was needed to combat inbreeding and insisted the display was educational.

But animal rights campaigners condemned the killing of Marius, saying it exposed the cruel reality of welfare even in Europe’s top zoos.

Marius’s plight had triggered worldwide outpourings of protest, including an offer to rehome him in Britain, with many saying they were sickened by a zoo killing a healthy animal.

Copenhagen Zoo said it was told by the European Association of Zoos and Aquaria (EAZA) that Marius was genetically too similar to the other giraffes in its breeding program. Because captive animals are bred from a limited gene pool, zoos are monitored to prevent inbreeding and ensure the health of future generations.

After announcing plans to have Marius put down, the zoo received offers of a new home – including one from Yorkshire Wildlife Park – as well as a private buyer who offered 500,000 euros (£410,000).

But bosses said the rules of EAZA membership meant animals could not be transferred to institutions that did not follow its rules on breeding programs.

The zoo’s scientific director said it was the same as parks culling deer to keep the whole population healthy.

He said: ‘Giraffes today breed very well, and when they do you have to choose and make sure the ones you keep are the ones with the best genes. The most important factor must be that the animals are healthy physically and behaviorally and that they have a good life while they are living, whether this life is long or short.’

He said the zoo didn’t give its eight giraffes contraceptives due to ‘unwanted side effects on the internal organs’ and in order to allow animals to display natural parenting behaviour. According to Danish media, Copenhagen Zoo destroys 20-30 animals a year, including bears, tigers and zebras.

He said institutions such as Yorkshire Wildlife Park should be reserved for ‘genetically more important’ giraffes and that the campaign to save Marius had gone ‘much too far’.

He said he had decided against sending Marius to another zoo because doing so would have opened the door to inbreeding and potentially removed a place for a giraffe whose genetic makeup was more valuable in terms of future offspring in captive breeding programs. He seemed caught off guard by the public protest, calling it “totally out of proportion.”

“People said, ‘If you kill the giraffe, I’ll kill you,’ ” he said. “It’s insane.”

“We don’t do it to be cruel; we do it to ensure a healthy population,” he Holst added. “You have to breed them to make sure the population is renewed.”

As for individual offers, he said giraffes were social animals and could not be kept in isolation.

A spokesman said parents were allowed to decide whether their children should watch what the zoo regarded as an important display of scientific knowledge about animals, adding that it would have been ‘foolish’ to let the meat go to waste. Doncaster-based Yorkshire Wildlife Park, whose Danish head of ‘hoofstock’ offered to rehome Marius, said it was ‘saddened’ by the news.

‘We have a state-of-the-art giraffe house built in 2012 with a bachelor herd of four male giraffes and the capacity to take an extra male, subject to the agreement of the European studbook keeper,’ it said.

However the park said it received no response by the time it learnt that Marius had been destroyed.

Stine Jensen, of Denmark’s Organisation Against the Suffering of Animals, said the killing showed Copenhagen Zoo was not ‘the  ethical institution that it wants to portray itself as being’.

Longleat Safari Park admitted it put down two lions and four cubs. The Wiltshire park said it had too many lions and they were growing violent. But visitors asked why new homes were not found.

One group, Animal Rights Sweden, urged people to stop visiting zoos as a protest. “It is no secret that animals are killed when there is no longer space, or if the animals don’t have genes that are interesting enough,” the organization said in a statement.

Marius was born in captivity at the Copenhagen Zoo, where there are seven reticulated giraffes, a species native to Africa. The species is not endangered, but it faces threats from habitat loss and hunting.

“A giraffe is not a pet; it’s not like a dog or cat that becomes part of the family. It is a wild animal.”

Giraffes are allowed to breed in captivity because it is part of their natural behavior in the wild, Mr. Holst said, even though breeding can produce what he called “a surplus animal.”

“As long as they are with us,” he said, “we want them to have a good life, with as much natural behavior as possible.”

Officials used a shotgun rather than an injection to kill the giraffe so that his meat would be safe for the zoo’s predator animals to eat. After an autopsy that was open to visitors as an educational opportunity, parts of Marius’s remains were fed to the zoo’s lions — and there is some left over.

Why Copenhagen Zoo Euthanised a Giraffe

The reaction to the euthanasia of Marius the giraffe at Copenhagen Zoo has highlighted cultural differences in attitudes to animals and death between the UK and Denmark.I first visited the Copenhagen Zoo around 20 years ago and met the zoo’s scientific director, Bengt Holst, who found himself recently at the centre of a campaign to save Marius, and is now the subject of another calling for his resignation.

The zoo had then, as it still does, a policy against using contraception for its animals and consequently a policy of euthanasia of the surplus animals that would arise as a result.

In contrast to most zoos around the world, which use contraception or sterilisation to control their animals’ reproduction, Copenhagen Zoo has chosen not to for two principal reasons. Some methods of contraception can have negative effects on an animal’s health and future reproductive ability, although slowly science is eliminating these.

But the Danes also strongly believe that being a parent is an enriching experience for their animals. The problem is that while it solves one animal welfare problem — the well-being of the breeding adults — it creates a subsequent ethical issue, that of what to do with the “surplus offspring”.

To humans, the concept of surplus offspring sounds wrong, but in the world of zoos, where space for endangered species and resources to keep them is limited, it is a different story. An enclosure to house giraffes is very expensive to build and maintain — and zoos do not have limitless pots of money. So if you allow animals to breed as often as they want, inevitably the result is animals perceived as surplus to requirements.

If Marius has many siblings or other relatives in the captive giraffe population, not just at Copenhagen but at other Danish zoos and even those across Europe, then his genes are not important in terms of maintaining genetic diversity. This is one of the goals that drives zoo conservation, as it is genetic diversity that allows species to adapt to changes in their environment — and zoos see themselves as providing a population safety net.

For wild animal populations this is of vital importance. So Copenhagen Zoo would argue that by allowing Marius to live — in any zoo, and especially one of those in Europe already well-stocked with individuals bearing his family’s genes, he is taking up limited and valuable space — space that should be allotted to an individual that will add to or help maintain genetic diversity.

This is a very pragmatic stance. To many people in Britain this goes against our cultural identity as a nation of animal lovers. Danes love animals, too, but express this in a different manner. They would, I suspect, agree with animal welfare experts in arguing that death itself is not an animal welfare issue; what is important is that the death is humane, and that the life that preceded it was good. In the UK we are perhaps too focused on longevity and not on quality of life. This is the key difference in attitude to the case of Marius the giraffe.

Conservation biology is driven by society’s recognition that human actions have driven many species to extinction and that we have a responsibility to do something about it. This is an ethical question, and again, it is society that determines what is right or wrong. Most societies around the world have determined that it is wrong to drive other species to extinction, but many differ on the question of how to save them.

So in this case, I’m sure that Copenhagen Zoo chose to euthanise Marius because it sincerely believes that this is the best course of action for giraffe conservation. Equally, others sincerely believe that this situation should have been avoided by the use of contraception, despite the welfare implications for the breeding adults.

It is perhaps time for us to remember that the nations of the world are jointly responsible for managing the world’s flora and fauna. Intentionally or not, this case has sparked an important debate. It is only by attempting to understand each other’s cultures that we can hope to make any progress on global issues such as wildlife conservation.