HOW OFTEN ARE LARGE MAMMALS KILLED IN ZOOS?
U.S. and European zoological organizations refuse to release figures for the total number of animals killed. But David Williams Mitchell, spokesman of the European Association of Zoos and Aquaria, or EAZA, estimates an average zoo in its 347-member organization annually kills about five large mammals, which adds up to 1,735.
The number doesn't include zoos and animal parks that don't belong to the association. Animal rights groups suggest numbers are much higher. The Associated Press contacted 10 zoos in Europe — two refused to comment, four said they never kill any animals unless severely ill and four said they kill between one and 30 animals every year. Two zoos in the U.S. said they only ever kill animals for "quality of life reasons."
WHY ARE ANIMALS KILLED?
Zoos euthanize animals because of poor health, old age, lack of space or conservation management reasons. EAZA policy for zoos in Europe suggests euthanasia may be used as a last resort to achieve a balanced population within breeding programs — Marius was killed to prevent inbreeding. But Williams Mitchell insists only "a fraction of 1 percent" of the killings are for such reasons. The idea is to maintain a group of genetically healthy animals in zoos that can be used to reintroduce the species into the wild should it become extinct.
Mike McClure, general curator at the Maryland Zoo in Baltimore, says his zoo's policies theoretically allow for killing animals for breeding purposes or lack of housing, but it's not something his zoo has done. Generally, he says, animals are only killed due to quality of life issues such as old-age or ill-health.
In Asia, the parent company for the Singapore Zoo said in a statement that "euthanasia of animals is necessary to maintain the health and welfare of the herd, as overcrowding could lead to injuries, stress, and disease outbreak. "
"All animals in zoos die at some point and maybe zoos forgot to tell people," said Jens Sigsgaard, zoological director at Aalborg Zoo in Denmark, which, like Copenhagen Zoo, performs open dissections of animals for educational purposes. "They come year after year. They probably think it's the same animals that were there when they came as kids."
WHAT DO ZOOS DO TO AVOID KILLING ANIMALS?
When animals reproduce, most zoos first try to find another one in their network they can send the offspring to. Earlier this week, a German zoo said it would send a monkey to the Czech Republic because he's produced so many offspring that he would soon start having children with his own relatives.
Zoos generally avoid selling the animals on the open market, fearing they will end up in poor conditions. Some European zoos and most zoos in the U.S. choose to use contraceptives, sterilization or separation of males and females to avoid breeding more animals than they can house.
Sharon Dewar, spokeswoman for the U.S. animal Population Management Center, says animals there are recommended to "breed only when sustainable housing for any offspring can be assured." That approach is dismissed as "totally wrong" by Bengt Holst at Copenhagen Zoo, who says breeding is important for an animal's well-being. EAZA's Williams Mitchell says there is an ongoing discussion and expects Marius' case to intensify the debate.
Cheryl Asa, director of the Association of Zoos and Aquariums Wildlife Contraception Center, says just because contraceptives are used it doesn't mean an animal will never breed. She also says "most of us are very happy to have our pet dogs and cats spayed and neutered, and I've not heard any of my friends or neighbors talk about worrying that their dog or cat was missing out on something in life if they hadn't had a litter of puppies or kittens."