Grebe hybrids are rare. Some crosses have been describes, such as Hooded Grebe (P. gallardoi) x Silver Grebe (P. occipitalis) (Storer, 1982). On Madagascar there appears to have been extensive hybridization between the endemic (and now extinct) Alaotra Grebe (Tachybaptus rufolavatus) and Little Grebe (T. ruficollis) (Voous & Payne, 1965).
Hybrids between Western Grebe (Aechmophorus occidentalis) and Clark’s Grebe (A. clarkia) have been described (Konter, 2009) and their numbers are increasing in at least two populations (Konter, 2011; Konter, 2012).
Konter, A. (2009). Occurrence of Clark’s Grebes and their hybrids with Western Grebes in Prairie Canada. Blue Jay 67, 26-33.
Konter, A. (2011). Interbreeding of Aechmophorus Grebes. Wilson Journal of Ornithology 123, 132-136.
Konter, A. (2012). Visual Assessment of Interbreeding by Aechmophorus Grebes. Wilson Journal of Ornithology 124, 713-720.
Storer, R. W. (1982). A Hybrid between the Hooded and Silver Grebes (Podiceps gallardoi and P. occipitalis). The Auk, 168-169.
Voous, K. & Payne, B. G. (1965). The grebes of Madagascar. Ardea 53, 9-31.