For anyone doubting the effectiveness of carrier pigeons — it might take a while, but it seems that they deliver the message eventually. In this case, it took over 100 years.
While out for a walk in a field in Ingersheim in eastern France, a couple found a small capsule containing a message sent by a Prussian infantry soldier over a century ago via carrier pigeon. Written in German, the message was addressed to a superior officer and described military maneuvers during World War I. The date isn’t easily legible but reads July 16 of either 1916 or 1910.