LONDON (Reuters) -- Captive carnivores such as lions, polar bears, tigers and cheetahs have difficulty adapting to life in zoos because they miss the variety of the wide ranges they roamed in the wild, scientists said.
Animal behaviorists at the University of Oxford in England had thought that carnivores fared less well in zoos and paced back and forth because they missed the thrill of the hunt.
But after analyzing data on 35 species of carnivores zoologist Dr Georgia Mason and her colleagues discovered that depriving the animals of their naturally large territories was an important factor in predicting how well they would adapt to captivity.
"We thought it would be something to do with hunting but we found instead that home-range size and the daily distance they travelled naturally was the predictor," Mason said in an interview Wednesday.
The most wide-ranging carnivores were prone to the worst problems in zoos, she added, and had high infant mortality rates, while those who stayed closer to home in the wild adapted best.
But Mason, who reported the findings in the science journal Nature, said the animal's body size was not a primary factor. Some large animals such as the grizzly bear, which has a home range of about 0.5 square km (0.2 square miles), do well in zoos, have a low infant mortality rate in captivity and spend about 11 percent of their day on average pacing.
Tigers and cheetahs, which normally cover much larger distances in the wild, spend more of their time pacing and have higher infant mortality rates in captivity.
The grizzly bear, Eurasian lynx, American mink, red fox and arctic fox, which are more stay-at-home types, adapt best to zoos, according to the researchers.
The study, which was partly funded by zoos and animal welfare and veterinary groups, has important implications for zoos eager to improve the welfare of carnivores in captivity.
The Federation of Zoos in Britain welcomed the results, although it said they could be open to misinterpretation.
"Nevertheless such research is invaluable in helping to ensure we continue to strive for the highest standards of animal welfare in keeping large endangered carnivores in zoos and wildlife parks," Dr Miranda Stevenson, the director of the federation, said in a statement.
Mason added that it was not just a matter of space for carnivores because in some cases the animals travelled a greater distance pacing than they would have in the wild.
"They can put the miles in, even in captivity, which makes us think that it is not just space and enclosure size but something more subtle, perhaps to do with day-to-day variety," she said.
Wolfyu Posted: Oct 2 2003, 02:28 PM
That's fairly interesting. I don't like the idea that pacing is their exercise, though. Perhaps that will change in the future!
And by the way...what's the definition of "Mortality Rate"? Is that considered 'the time that they die' or 'the chance that they will die'?
jwa1107 Posted: Oct 2 2003, 03:02 PM
an infant mortality rate would be the ratio of live-born babies in captivity that die within the first year versus those that survive beyond 1 year...
Capt.Rutlinger Posted: Oct 3 2003, 11:02 AM
yep it's very interesting and it raises the question Should we lock some animals up in to small exhibits like the one in zoos, knowing that they will not like being locked up
Juggernaut Posted: Oct 3 2003, 12:32 PM
you do know that most of these animals wouldn't even survive a week in the wild let's face it there probably happy cause hey you got food shelter mate and all you do is sit around and look like an animal wouldn't you like a life like that i would in fact there are even cases where animals had an opportunity to escape like the keeper left the door open and the animal either ignored it shut it went out and quickly ran back inside when it came across the first guest
jwa1107 Posted: Oct 3 2003, 12:48 PM
the point should be making zoo habitats big enough for the animal to feel comfortable and not seem like it is pacing while retaining control over the animal.
at the Dallas Zoo there is a rather large tiger exhibit with two Bengal tigers. they have over an acre of wooded habitat to roam and play and sleep - more exhibits should be built like this, not the small concrete and iron bars of older exhibits.
superlion Posted: Oct 3 2003, 01:46 PM
Though an acre is hardly anything compared to the huge ranges of tigers in the wild... it is good, though. The Oakland Zoo had a really nice big exhibit for the lions, I think it's about four acres.
jwa1107 Posted: Oct 3 2003, 02:42 PM
unfortunately viable zoos cannot recreate natural ranges of 10 to 200 square miles! (there are 640 acres in one square mile!)
for example, the Oakland Zoo itself is only a portion of a 525-acre city park. The zoo is only 100 acres.