字幕表 動画を再生する 英語字幕をプリント I love going to the zoo, you get to see monkeys, and lions and tigers and bears oh my! But are they really such a great thing? Hey animal lovers, Julia here for DNews I've loved zoos my whole life. There was one I remember that made me wanna want to share how awesome animals are! Fast forward a few years and well here I am. Making videos about science and animals on the internet. But now, I'm older, wiser and really ambivalent about zoos. Zoos have changed a lot since their conception. Environments used to be basic, easy to build and didn't provide animals with the opportunity to interact with their surroundings, which was detrimental to their health. Think of classic zoos, animals in a small cage with nothing but concrete and bars. Zoos today have changed this practice into providing “enriched environments” which include increasing space, adding natural sound, and introducing elements of their natural environments. But most of the time changing the cage in which an animal is held isn't enough since what the animal may find stressful is hard to assess. When these stresses go unnoticed the results can be really bad. For example the most recent loss was an entire stingray population at the Chicago Zoo because of low oxygen levels in their tanks. In this case it was a malfunction of the habitats “life support system” that caused the death of four southern stingrays and 50 cownose rays. This is the second incident that has taken place at the Chicago Zoo, in 2008 they lost 19 stingrays to a heating malfunction and they have decided to close the exhibit for good. Light and sound also have negative effects on animals held in captivity. According to a study published in Applied Animal Behaviour Science noise levels measured in two Northern California zoos had sounds ranging from 62 to 72 decibels compared to the noise levels of a rainforest, which can average about 27 db. Light levels are also higher than they're supposed to be, maintaining a low light situation keeps animals less aggressive but if you don't have any lighting how are you supposed to see the animals? When it comes to feeding, nothing seems easier than to have your food delivered and served but when it comes to lions and other carnivorous animals getting served zoo slop can actually put them in danger. Researchers at the San Diego Zoo studied cheetahs and their eating habits while in captivity. They gave one group the regular zoo cuisine of ground horse meat with a mix of vitamins and minerals but gave a second group thawed bovine fetus or half of a large carcass. They noticed the group eating the carcasses took more time chewing and smelling their food than the first group. Pretty much they acted as they would normally in the wild, besides the whole hunting part. Researchers discovered that processed foods lack a “hassle factor” which cheetahs need to dull down their molars and is critical for good dental hygiene. The treatment of elephants are at the forefront of the debate against zoos. Elephants are used to living in huge matriarchal families and are innately social creatures, but by being held in captivity with only one other elephant, that they may not even be compatible with, causes stress and shortens their lifespan. Elephants in captivity only live half as long as those who live in natural wildlife preserves. African elephants can expect to live to 36 years old in Kenya's Amboseli National Park compared to zoo elephants who live to be about 17 years old. Although some accredited zoos, like the Bronx Zoo and the San Diego zoo are able to extend the lives of their elephants, the San Diego boasts some of their elephants live to be 40 years old. But not all zoos have the money to keep their parks running. Most zoos struggle with financing all of the needs of their animals, employees and maintenance of their parks. Some zoos apply for accreditation through the Association of Zoos and Aquariums but only 10% of the 2,800 zoos in the U.S. actually get it this also distinguishes zoos from “roadside zoos” which are known for animal endangerment and mismanagement. In order to be part of AZA each zoo must go through a process where experts examine the zoos to make sure they are up to code and have employees who are qualified to work in those environments. Accreditation matters because it makes these zoos eligible for grants, able to breed and loan animals with other zoos and hire the best workers in the business. But before you go rally and protest your nearest zoo, it's not all bad news bears. I cannot overstate the great educational value of zoos. Zoos are a great place to learn about animals for young and old alike. It's a place to literally come face to face with some of the rarest animals in the world. Zoos introduce people to what the animal populations are like around the world and educate people about conservation efforts. Visiting a zoo might even get you to donate to these efforts. Meeting a Mountain Gorilla in person might make you want to save this endangered animal. And zoos want to save endangered species too. Dozens of zoos in North America actively participate in the Association of Zoos and Aquariums Species Survival Plan Program (SSP), which concentrates on finding dwindling populations, bring them into captivity and growing them until they are ready to be released into their natural habitat. SSP related programs have bolstered populations such as black-footed ferrets, California condors and red wolves. Zoos also provide health care and services to animals who need it. Many animals held in captivity were found in the wild wounded or stranded. Zoos give these animals a second chance at life, one they wouldn't of gotten had they been left in the wild. When it comes to pros vs cons, as long as they are well managed and accredited and they work on creating more natural habitats for their animals, zoos bring people closer to nature and might help save some of the most imperiled species on the planet. What do you think? How do you feel about zoos? Do you have a favorite zoo? Tell us some of your recent zoo experiences down in the comments below.