But the weekend killing of the healthy two-year-old animal has turned into what observers have called a public relations "disaster" and "debacle" for the zoo. It also shone a light on the seldom seen practice of how zoos dispose of animals that they just don't want or need.
"I think that it demonstrates a real tone-deafness as to concerns about the ways that zoos operate," says GeoffD'Eon, a Halifax documentary-maker whose recent production Zoo Revolution explored the ethical debate around zoos.
"It may make sense to euthanize that giraffe in the context of the breeding program, but to do it in the way that they did it I think represents a public relations disaster for that particular zoo, and by extension other responsible zoos with whom they might be allied."
The public nature of Marius's demise drew a lot of attention, setting off swaths of social media reaction strongly opposed to the zoo's actions. Senior staff at the zoo received death threats Monday.
"What's interesting in this case is the utter and complete stupidity of the zoo in doing this in front of the public," says Rob Laidlaw, executive director of the animal welfare charity Zoocheck Canada.
Issues around how to dispose of zoo animals "crop up time and again," he says, but aren't something the public knows a lot about.
"It is part of the dark underbelly of the whole captivity industry, and I don't think it's fitting with public sentiment. Most people have empathy for the animals and certainly zoos capitalize on that by naming animals, by making them celebrities."
The Copenhagen Zoo has said the decision to kill Marius followed a recommendation by the European Association of Zoos and Aquaria because the zoo already had already several giraffes with genes similar to those of Marius in its breeding program.
Other options such as moving Marius to another facility or using contraceptives were ruled out. In fact, Copenhagen officials said they turned down two offers to take Marius, one from a wildlife park in Yorkshire that had his older brother and another from a Swedish zoo, for genetic and accreditation reasons.
For zoo visitors who marvel at the cuteness or the majesty of the animals they see, these kinds of high-level scientific machinations are not be front of mind.
But D'Eon says genetic regulation lies at the heart of the extensive breeding programs that zoos use to manage their populations.
"To a large extent, they're pretty successful, and they're there for a good reason," he says, noting concerns from years back that linked inbreeding of zoo animals with high mortality rates.
"In Copenhagen, the zoo is invoking those principles. They're saying … we can't breed with this particular male giraffe because it's surplus to our needs from the point of view of the genetic bank."
So that opened up the question of what to do with Marius, and death rose to the top of the zoo's list.
It wasn't the first time. According to a report in the New York Times in 2012, the zoo's director of conservation, Bengt Holst, says the facility annually puts to death 20 to 30 healthy exotic animals. And it is not the only zoo that does this.
"Euthanasia is part of the program. Zoos routinely kill surplus animals," says D'Eon.
"They also sell them in some cases. A lot of zoo animals meet a worse fate than the one that this particular giraffe did. They're sold to hunting lodges. They're sold to road shows."
D'Eon says he doesn't know of instances of euthanasia at Canadian zoos, but he would be astonished if it didn't happen.
In a statement late Monday, Canada's Accredited Zoos and Aquariums, the organization that describes itself as the "national voice of the zoo and aquarium community, said:
"One aspect of any effective and ethical captive breeding program is taking steps to ensure responsible population management control (i.e. birth control, separate males/females to control breeding, relocation and euthanasia)."
In went on to say that euthanasia is a "very difficult and sensitive practice that must be done following careful reflection and search of alternatives, including transfer."
Accredited zoos must have detailed euthanasia policies in place and follow "generally accepted procedures to ensure the practice is carried out in a humane fashion."
CAZA also noted that one of the key missions of accredited zoos and aquariums is to promote a better understanding of the natural world, but it didn't unconditionally embrace the weekend actions in Denmark.
"While we understand that the Copenhagen Zoo saw this as a 'teachable moment' and an opportunity to educate visitors on what, in the wild, is a natural occurrence, we believe that the educational value of such demonstrations must be assessed very carefully against their potential to shock and desensitize, and to raise additional and difficult questions, particularly among children."
In a separate statement, the Toronto Zoo said it couldn't comment on the specific actions at the Copenhagen Zoo, but it noted that it has an obligation to "responsibly regulate the size" of its animal population. Options include relocation to other accredited facilities, release into the wild and birth control.
"When none of these measures are feasible without causing stress or impacting upon group behaviour, then individual animals may be euthanized in a fear-free environment," the zoo said. "The humane culling of animals should take place at times that approximate natural processes of 'biological crossroads' such as birth, weaning or the leaving of the family group."
After Marius was killed, his remains were carved up and fed to large felines at the Copenhagen Zoo.
D'Eon says he doesn't have a particular problem with the issue of lions being fed the giraffe meat.
"Lions eat giraffes every day in our world, nothing new there. But when you package this whole spectacle together, where the giraffe is dissected and fed to the other animals, I don't think it signals compassion and caring in the way that would be most useful for zoos to do."
Feeding animal meat to other zoo animals is common practice, says Laidlaw.
"You get a lot of animals — they're not charismatic animals usually like giraffes and it's not done in front of the public, but you get animals, usually hoofstock that are killed and fed to other animals, and again I just think it is part of this whole debacle in terms of public relations perpetrated by the Copenhagen Zoo."
"I think this is something that they thought would show them as this bold institution that's making the tough choices, and they're showing children the circle of life and all this nonsense, and I just don't think it's worked."
Not so bold
If there was any value in what happened at the Copenhagen Zoo, Laidlaw thinks it is "counter-educational."
"I think it's showing that OK, we've got our programs in place, we have our needs as an institution or as an industry, but when our needs aren't being met, these animals are disposable. I think it's sending exactly the wrong message and I hope it also makes people realize that most of these breeding programs that are zoo-based aren't necessary."
Marius wasn't part of a subspecies that is endangered, and Laidlaw hopes that will spark further public debate.
"Hopefully people will say 'Well if that's the case, why on Earth was breeding allowed in the first place?'"
D'Eon says he has sympathy for zoos and the work they are trying to do in conservation. He has no sympathy for people at the Copenhagen Zoo as they deal with the "public relations firestorm that they've lit.
"If they didn't anticipate this firestorm, they were incredibly naive because this was entirely predictable, given the pre-existing opposition to zoos. It was entirely predictable people would be upset by this."