Silvery Grebe

Macá Plateado

Podiceps occipitalis

Length: 280mm. Sexes alike. Bill very dark plumbeous grey; iris orange red; forehead, crown, chin and throat ash grey; occiput and nape black; golden cinnamon pin feathers form ear tufts on sides of head; neck pure white, with upper hind neck black turning lead-grey on the lower part; above and coverts, slate grey; primaries, brownish grey; secondaries white with greyish brown spots on outer vexillum; axillaries white with grey spots on wing tips; breast and underparts pure white and silky appearance; flanks plumbeous grey. Legs plumbeous grey. Chicks are born grey with blackish bands on throat and above; underparts pure white. Juveniles resemble adults but top of head is grey with no black; no ear tufts; throat and chin are white. Habitat and behaviour: gregarious, the Silvery Grebe is encountered in vast groups ranging from parties of 10 or 20 individuals to flocks of hundreds and even thousands of individuals. Common on lakes, ponds, freshwater bodies and brine waters. Like all members of the family it is an excellent swimmer and diver. Vocalisation consists of songs or calls, short and high-pitched. The alarm call is a repeated shriek. During the breeding season both sexes actively take part in a very elaborate courtship ritual. The nest is built on floating rafts made of aquatic vegetation. Mating takes place on the nest; afterwards, the male runs swiftly over the back of the female and leaves the nest, all the time facing her. It nests in colonies, the female laying 2-6 white eggs. It feeds on insects, insect larvae, pupae and small snails. It also swallows large quantities of its own feathers. Often seen in mixed flocks alongside of the White-tufted Grebe (Podiceps rolland) and in south Patagonia, with the Hooded Grebe (Podiceps gallardoi); however, the Silvery Grebe stands out for being tamer and trusting in the presence of humans.

Range: common in all Patagonia and Islas Malvinas; during March and April it migrates to the north and is back by September-October. During migration it is frequently observed in coastal waters. The nominate race found throughout this region is Podiceps occipitalis occipitalis.