ON the day when young Shetland Wrens {Troglodytes t. zetlandicus) left their nest on Fetlar small quantities of a rufous-brown paste were noticed on a boulder under the entrance. Some of it was scraped off and later examined under the microscope. It was found to be composed mainly of arthropod remains in a triturated condition. Beyond reasonable doubt this material was voided orally by the young ...

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