Often accompanied by his sidekick Little Frank - a glove puppet made in his own image - Frank became a regular face on TV in the 1980s and 1990s.

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The Beaver's blend of darkly humorous drama - not to mention belief in a talking glove puppet - did not appeal to box office audiences in the States.

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Humans wearing a condor-shaped glove puppet (developed by Mr Wallace) have fed the nestlings, and they have been kept in close proximity to a group of older condors so that they can observe and learn from their elders' behaviour.

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