Found in The Encyclopaedia of Fads and Fallacies by Thomas Jay (Elliott Rightway Books, Kingswood Surrey 1958) a small section on ostrich fallacies. The reference to a Bergen Evans
book is probably his Natural History of Nonsense.
The Diet of the Ostrich
There is a foolish notion that the ostrich can digest iron. Many zoos and menageries have quite a lot of trouble because the public will feed ostriches with nails or bits of metal. As Bergen Evans points out in one of his books, it rarely occurs to people that the purposes of the bars, moats, and walls at zoos is to protect the animals from us.
An ostrich does not bury its head in the sand thinking that it is hiding itself. But what some politicians will do without the metaphor I don't know. If alarmed, or suspicious, the ostrich will lie flat on the ground with its head stretched out flat in front so that it can size up the situation. And it can do that very well from that position.