Carcass feeding and euthanization

Carcass feeding at Copenhagen Zoo:

Finding and processing food is a very important part of the natural behaviour of any species and takes up quite a bit of time for the animals.
In Copenhagen Zoo enrichment and feeding behaviour is one of the major focus areas. The zookeepers spread the food in the enclosure, hang it from trees and branches, hide it in burrows and put it in feeders and automats that work on timers to accommodate a natural feeding time pattern.

One of the greatest enrichment efforts for the big carnivores is carcass feeding. By carcass feeding a lot of the animal’s natural feeding behaviour is supported: dragging, tearing with teeth and claws, using muscles in the jaws, neck and forelegs, grooming themselves thoroughly afterwards and so forth – this is enrichment that can last for days.

In Copenhagen Zoo we find carcass-feeding to be a good ethical choice when keeping great carnivores in captivity. Being fed with natural cuts of meat including skin and bones, the carnivores get to eat the way nature has evolved them to. This supports the animal’s natural behavior and it leaves the visitors with a scene that includes a much more natural, active and well-stimulated carnivore all together.

The visitors get to experience a piece of true carnivore behavior and what nature is also about.

Listed below are some facts and information about surplus animals and euthanizing:

  • Euthanizing does NOT conflict with high animal welfare. In cases where euthanizing is necessary it is carried out by professional veterinarians and the animals does not suffer any pain
  • Surplus animals are a natural phenomenon in the wild and are an unavoidable result of sound breeding management in captivity. If the animals are not allowed to mate we deprive the animal’s natural behaviour. Courting, sexual behaviour and parental care takes up a lot of time for most mammals, enriches them and the natural behaviour results in high animal welfare.
  • Animals only become surplus animals when they reach a certain age where they would have left the group anyway.
  • Surplus animals also occur in the wild where young animals often die of hunger or are killed by other predators. It can be difficult to understand why a Zoo chooses to breed the animals if there is a risk of getting surplus animals, but research shows that e.g. sexual behaviour and parental care is of most importance for the welfare of the animals. Copenhagen Zoo is a modern zoo and is – as any other research institution - run by facts and the latest behavioural research.


We take our responsibility for animal welfare very seriously. Our staffs are professionals and they continually working to improve the methods to increase the animals natural behaviour and to raise public awareness.

Q & A to scientific director Bengt Holst

Why does Copenhagen Zoo euthanize healthy animals?

Copenhagen Zoo’s animals are part of an international breeding programme which aims at ensuring a healthy animal population in European zoos. This is done by constantly ensuring that only unrelated animals breed so that inbreeding is avoided. If an animal’s genes are well represented in a population further breeding with that particular animal is unwanted. When an animal's genes are well represented in the breeding programme and there is no place for the animal in another zoo, the European Breeding Programme has agreed that the animal is to be euthanized. This is a situation that we know from other group animals that breed well. When breeding success increases it is sometimes necessary to euthanize.

We see this as a positive sign and as an insurance that we in the future will have a healthy animal population in European zoos. The same type of management is used in deer parks where red deer and fallow deer are culled to keep the populations healthy. The most important factor must be that the animals are healthy physically and behaviourally and that they have a good life whilst they are living whether this life is long or short. This is something Copenhagen Zoo believes strongly in. 


Why are the animals not given contraceptives?

In Copenhagen Zoo we let the animals breed naturally. With naturally we mean that they will get young within the same intervals as they would in the wild. That means that the animals get to carry out their natural behaviours. Parental care is a big part of an animal’s behaviour. It is a 24 hour job in longer periods of their lives and we believe that they should still be able to carry out this type of behaviour also in captivity. Contraceptives have a number of unwanted side effects on the internal organs and we would therefore apply a poorer animal welfare if we did not euthanize.


Why not transfer the animal to a zoo which is not part of the breeding programme or to a zoo that is interested in getting the animal?  

Only zoos that follow certain rules can be part of international breeding programmes. In Europe this is only the zoos that are members of the European Association of Zoos and Aquaria (EAZA). EAZA is an association that counts just over 300 members.

As a member of EAZA you agree to the following rules of not selling animals, working on a scientific basis and ensuring animal welfare. The international breeding programmes are fully controlled and open and are collaborations between institutions that follow from the same set of rules. This is important for the breeding programmes to work.


Why can't the animal be released in the wild?

It is not easy to reintroduce an animal to the wild. Many factors have to be considered and these are described in detail in IUCN's Reintroduction Guidelines (IUCN: International Union for Conservation of Nature). You can not just set animals ‘free’ if there is no possibility of them surviving.  First of all you have to consider what made the animal endangered in the first place and whether this is still the case.

Another important factor is local support as it is the local community that has to live with the animals. Unless it is part of an official release programme animals are not reintroduced. The natural habitats will be full of dangers and challenges so the animals that evidently are part of a reintroduction programme will be carefully selected to increase the chance of survival.


What does Copenhagen Zoo do with the dead animals?

After euthanasia the animal will be autopsied as we do with all our animals. That way we will collect important knowledge about the animal – knowledge that can benefit other animals of the same species. In case of euthanizing for example an antelope, horse or giraffe, the carcass will be used as food for the Zoo’s carnivores. When animals are euthanized with an overdose of aesthetic it is not possible to use the remains for food. However if the animal is first anaesthetized and then put down with a bolt pistol (same procedure as with horses and cows) it can be given to the carnivores.

Why does Copenhagen Zoo do public autopsies?

At Copenhagen Zoo we perform autopsies on all animals that die - from the smallest mouse to antelopes and elephants. We do this in order to gain new knowledge about the animals and to prevent diseases. Sometime, when we need to perform an autopsy, we invite our guests to observe our vets conducting the important work.

The vets are good communicators and during the autopsy they explain what we see, and how the whole organism works in an educational effort directed towards our guests. We are always careful to inform our guests beforehand that the process might be considered overwhelming for some and what they can expect if they chose to attend the autopsy.

By scientific director Bengt Holst


A lot has been said about the euthanasia of the above mentioned giraffe. People and organisations from all over the world have stated their criticque or support of the action, and as so often happens there have also been a lot of misunderstandings. Consequently there is a need for clarification.

In the article scientific director Bengt Holst has described what REALLY happened as well as the background for the decisions.

The three main points of criticism were:

  • Euthanasia/culling of a 2 year old male giraffe
  • Inviting the public to watch the autopsy
  • Feeding the carcass to the lions

Please find the answers in the full article here: