Found some eggs, what're they from? (North Scotland)

In North Scotland, near Castletown, an intriguing discovery has been made: a collection of empty eggs, each roughly the size of a 50 pence piece. The finder, u/CharlieDePupper, thoroughly examined the eggs using weight measurements and a torch light to confirm their emptiness. This unique find raises questions about the species that laid these eggs. As the community discusses the potential origins, insights from local wildlife experts and enthusiasts could shed light on this fascinating discovery and the ecological context surrounding it.