Great Grebe

The great grebe, known scientifically as Podiceps major, stands as the largest grebe species in the world. With a stately presence, it resembles a goose or cormorant more than its grebe relatives. Adults typically measure between 67 to 80 cm in length and weigh around 1,600 grams, though they can reach weights of at least 2 kg. Their plumage is a striking mix of buffy-rufous on the neck and chest, a blackish back, and a whitish belly. The head is a sooty gray crowned with a reddish-brown eye, making them quite distinctive in appearance.

Identification Tips

When identifying the great grebe, look for its large size and unique coloration which set it apart from other birds. The combination of a buffy-rufous neck, blackish back, and whitish belly, along with a sooty gray head and reddish-brown eye, are key characteristics. Their size and stature are reminiscent of geese or cormorants rather than typical grebes.

Habitat

The great grebe is found in a variety of open waterways, predominantly on low altitude lakes, sluggish rivers often surrounded by forests, and estuarine marshes. During the breeding season, they prefer the vegetated inlets of large lakes, while non-breeding individuals may inhabit estuaries, bays laden with kelp, and occasionally the open sea. Coastal non-breeding birds may reside in these areas throughout the year.

Distribution

This species has a broad range, with the main population extending from southeastern Brazil to Patagonia and central Chile. A disjunct population is found in northwestern Peru. The southern Chile population is recognized as a separate subspecies, P. m. navasi.

Behaviour

Great grebes are known to form large groups, sometimes numbering in the hundreds. They exhibit moderate social behavior during the breeding season, occasionally forming colonies. Outside of breeding, they are often seen in estuaries and bays.

Breeding

Breeding season for most populations occurs from October to January, with timing becoming later the further south one goes. In Peru, nesting is in September and October, with a possible second clutch in January or February. The great grebe lays three to five eggs, sometimes six, and may raise two broods simultaneously.

Diet and Feeding

The diet of the great grebe is predominantly fish, including those over 11 cm in length, though they generally consume smaller fish. They may compete with the neotropic cormorant for fish, but the latter often takes larger prey. In addition to fish, they consume insects, crustaceans, mollusks, and during winter along the coasts, their diet may consist of nearly half crabs. They have also been known to prey on the young of other waterbirds, particularly coots.

Conservation status

The great grebe is currently listed as Least Concern by the IUCN. Their habitats, especially in the southern parts of their range, remain largely intact and have not been extensively cleared, contributing to their widespread and common status throughout their range.