Undoubtedly, the most stressful time for any wild animal is when it is captured and transported. For this reason I disagree with these jumping contests. The frogs are usually captured, held and restrained in a completely inappropriate way and released after the competition. This teaches people that wildlife is at their disposal purely for their entertainment no matter what the end result for the animals involved are. Teaching people to leave wildlife where it belongs is at the root of any conservation message, and these exhibitions do nothing for conservation. I can't imagine anybody who has an interest in frogs as pets or in their conservation would be happy to see other frogs in a situation where they are performing for entertainment by literally being scared to death.
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...the oldest task in human history: to live on a piece of land without spoiling it."
Aldo Leopold (1938)
"Sometimes I think the surest sign that intelligent life exists elsewhere in the universe is that none of it has tried to contact us."
Calvin and Hobbes (Scientific Progress Goes 'Boink', 1991)