Arthritis c关节炎) is an illness thatcan cause pain and swelling in your bones. Toads (蟾蜍),a big problem inthe north of Australia, are suffering from painful arthritis in their legs andbackbone, a new study has shown. The toads that jump the fastest are morelikely to be larger and to have longer legs. (46)
The large yellow toads,native to South and Central America, were introduced into the north-easternAustralian state of Queenslandin 1935 in an attempt to stop beetles and other insects from de-stroyingsugarcane crops. Now up t0 200 million of the poisonous toads exist in thecountry, and they are rapidly spreading through the state of Northern Territory at a rate of up t0 60 kma year. The toads can now be found across more than one million squarekilometers. (47) A Venezuelanpoison virus was tried tin the 1990s but had to be abandoned after it was foundto also kill native frog species.
The toads have severelyaffected ecosystems inAustralia.Animals, and sometimes pets, that eat the toads die immediately from theirpoison, and the toads themselves eat anything they can fit inside their mouth._ (48)
A co-author of the newstudy, Rick Shine, a professor at the University of Sydney,says that lit-tle attention has been given to the problems that toads face.Rick and his colleagues studied nearly 500 toads from Queenslandand the Northern Territoryand found that those in the latter state were very different. They were active,sprinting down roads and breeding quickly.
According to the results ofthe study, the fastest toads travel nearly one kilometer a night. (49) But speed and strength come at aprice-arthritis of the legs and backbone due to con-stant pressure placed onthem.
Inlaboratory tests, the researchers found that after about 15 minutes of hopping,arthritic toads would travel less distance with each hop (跳跃). _ (50) These toads are so programmedto move~ apparently, that even when in pain the toads travelled as fast and asfar as the healthy ones, continuing their constant march across the landscape.
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