The largest extant species of bird measured by mass is the common ostrich (Struthio camelus), closely followed by the Somali ostrich (Struthio molybdophanes).
[2] Ostrich eggs are the largest of any bird, averaging 1.4 kg (3.1 lb).
[3] The largest wingspan of any extant bird is that of the wandering albatross (Diomedea exulans) of the Sub-Antarctic oceans.
[4][5] The largest wingspan of all time likely belonged to Pelagornis sandersi at roughly 5.2 m (17 ft).
[7] [kg (lb)] The following table is a list of the heaviest extant bird species based on maximum reported or reliable mass, with the average weight is also given for comparison.