In Croatia there is one city with a legend that during the Ottomans siege of the city, after running out of food, they took the last chicken and fired it from the cannon into Turkish camp, which made besiegers believe they have plenty of food and abandoned the siege.
Few years ago I read Umberto Eco's Baudolino and there was almost the same story just this time it was a cow, and Italians vs Imperials (and this is based on the existing legend, so not just something Eco made up)
The wiki page also implies this is just a variation of the story of Herculanus of Perugia, and a sentence in wikipedia here calls it an "old ruse".
How old and common is this "ruse", and are there other examples in history or historical legends and story telling? I also wouldn't mind to find as many the versions of this story as possible
There's a similar legend, of the origin of the name of the city Carcassonne, originally a Roman town. Dame Carcas, beseiged by Charlemagne, drops a well-fed pig off the castle walls after 5 years, so Charlemagne gives up and is going home. Dame Carcas begins to ring the town bells in celebration, and one of Charlemagne's soldiers yells, "Carcas sonne!" ( Carcas rings!). The French wikipedia page suggests it's oral tradition from a vanished medieval chanson de geste ( how would they know, if it's vanished?) but admits the first publication of it is 16th century. The legend has long been selling pictures of a beautiful woman dropping a pig off the walls.
The Samguk Sagi - a twelfth century text, but one drawing on much older sources - also says that when Han soldiers besieged a castle of the Goguryeo kingdom in 28 CE, and when the food and water supplies were nearly depleted, the Goguryeo counsellor Eulduji devised a plan by sending the Chinese army carp, water plants, and fine alcohol. The Han Chinese, assuming there was still water and supplies in the fort, retreated.