Provisioning of Slavonian Grebe Podiceps auritus chicks at nests in Scotland

摘要

Slavonian Grebes Podiceps auritus nest on partially floating platforms constructed from emergent vegetation (Fjelds 2004). Clutch sizes vary from three to ten eggs, although larger clutches tend to be found in continental inland breeding populations compared with the North Atlantic populations (Ferguson & Sealy 1983, Fjelds 2004). Incubation starts after the first egg is laid (Fjelds 2004). Consequently, hatching is asynchronous. This provides a parental dilemma between optimising the number of eggs that hatch, while brooding and feeding growing chicks, and guarding against the threat of nest predation (Simmons 1974, Kloskowski 2001).