Egg with no nest

At LFGP this morning there was 2 Oystercatcher, 2 Little-ringed Plover, 2 Redshank, 20-30 Lapwing, the usual BH Gulls and Common Terns + chicks, 5-10 House Martin and even a Sand Martin graced our airspace, but no sign of any other hoped for waders.

A Great Crested Grebe was sat on one of the nearby mini rafts and we weren't paying that much attention until it slid off, revealing a lone egg, but not a single piece of nest material. One might be inclined to believe that attempts to nest build were undermined by various species like Coot and Black-headed Gulls stealing their nest material, so they decided they could manage without?