Black-necked grebe

Podiceps nigricollis

Photo by Gerard Visser (Internet Bird Collection)

Common name:
black-necked grebe (en); mergulhão-de-pescoço-preto (pt); grèbe à cou noir (fr); zampullín cuellinegro (es); schwarzhalstaucher (de)

Taxonomy:
Order Podicipediformes
Family Podicipedidae

Range:
This species occurs in three disjunct subspecies. P.n. nigricollis breeds from western Europe to western Asia,  in central and eastern Asia as far as north-eastern China and extreme south-eastern Russia, and with a few population in East Africa. Some population migrate south to winter around the Mediterranean, in the Middle East and in Japan and southern China. P.n. gurneyi is found in southern Africa, and P.n. californicus breeds in south-western Canada and in the western United States and migrates south as far as Guatemala.

Size:
These birds are 28-34 cm long and have a wingspan of 56-60 cm long. They weigh 265-450 g.

Habitat:
The black-necked grebe breeds in small, shallow, highly eutrophic water bodies with lush vegetation, such as freshwater marshes and lakes, also using reed beds, fish ponds and sewage farms. Outside the breeding season they use saltwater lakes, estuaries, saltpans, and inshore shallow bays and channels.

Diet:
They feed mainly on adult and larval insects, such as aquatic bugs, beetles, damselflies, dragonflies, midges and brine flies, also taking snails, crustaceans such as brine shrimps, polychaete worms, small frogs and tadpoles, and small fish.

Breeding:
Black-necked grebes can breed all year round, varying among different parts of their range. They are monogamous and often nest in dense colonies. Each pair build a nest that consists of a mound of algae and other soft plant matter, anchored on an underwater plant in open water. There the female lays 2-5 eggs which are incubated by both parents for 20-22 days. The chicks leave the nest immediately after hatching, and are fed and carried on the backs of both parents until they fledge, about 21 days after hatching.

Conservation:
IUCN status - LC (Least Concern)
This species has a very large breeding range and the global population is estimated at 3,9-4,2 million individuals, possibly being the most numerous of all grebes. The overall population trend is uncertain, as some populations are decreasing, while others are stable, have unknown trends or are increasing.

Australasian grebe

Tachybaptus novaehollandiae

Photo by J.J. Harrison (Wikipedia)

Common name:
Australasian grebe (en); mergulhão-pequeno-australiano (pt); grèbe australasien (fr); zampullín australiano (es); Australischer zwergtaucher (de)

Taxonomy:
Order Podicipediformes
Family Podicipedidae

Range:
This species is found throughout  Australia, in southern Indoneasia, New Guinea, the Solomon islands, Vanuatu, New Caledonia and recently colonized several areas in New Zealand.

Size:
These birds are 23-27 cm long and have a wingspan of 39-40 cm. They weigh 100-230 g.

Habitat:
The Australasian grebe is found in various inland wetlands, such as marshes, swamps, ponds, lakes and small reservoirs, preferring shallow areas with floating vegetation. They are found from sea level up to an altitude of 1.000 m.

Diet:
They feed mostly on small fishes, aquatic insects, spiders, crustaceans and snails, but will also take some seeds and other vegetable matter. They are also known to occasionally eat frogs.

Breeding:
The breeding season of the Australasian grebe is variable and possibly stimulated by flooding. The nest is a small floating platform of vegetable matter, placed among emergent vegetation. The female lays 4-5 pale blue eggs which are incubate by both parents for 23 days. The chicks are able to swim from birth and are cared for by both parents for 8 weeks. They may not yet be able to fly when they become independent. Each pair can raise up to 3 broods per year.

Conservation:
IUCN status - LC (Least Concern)
This species has a very large breeding range. The overall population trend is increasing, although some populations may be stable and others have unknown trends, and some of the smaller island populations may be at risk due to habitat changes such as the drainage and exploitation of underground water supplies.

Great crested grebe

Podiceps cristatus

Photo by Ken Billington (Wikipedia)

Common name:
great crested grebe (en); mergulhão-de-crista (pt); grèbe huppé (fr); somormujo lavanco (es); haubentaucher (de)


Taxonomy:
Order Podicipediformes
Family Podicipedidae


Range:
This species is found across most of Europe and central Asia, wintering also in southern Asia. There are some scattered colonies in Africa, from Tunisia and Egypt in the north, through a few colonies in central Africa and into South Africa. There are also nesting colonies in southern Australia and New Zealand, with individuals wintering in eastern and northern Australia.


Size:
These birds are 46-51 cm long and have a wingspan of 59-73 cm. They weigh 0,8-1,4 kg.


Habitat:
Great crested grebes are mostly found on fresh or brackish waters with abundant emergent and submerged vegetation, showing a preference for non-acidic eutrophic waterbodies with flat or sloping banks and muddy or sandy substrates, and with large areas of open water. They are can also be found in swamps, saltpans, estuaries and reservoirs.


Diet:
They eat fishes, aquatic insects, amphibians, crustaceans, spiders and seeds.


Breeding:
The breeding season of the great crested grebe varies between different parts of its range, occurring in April-September in Europe and Asia, all year round in Africa and in November-March in Australia. The nest is a platform of aquatic plant matter either floating on water and anchored to emergent vegetation or built from the lake bottom in shallow water. The female lays 3-4 eggs which are incubated by both parents for 27-29 days. The chicks leave the nest soon after hatching and are often carried around on the backs of their parents, fledging 71-79 days after hatching.


Conservation:
IUCN status - LC (Least concern)
This species has an extremely large breeding range and the global population is estimated at 920.000-1.400.000 individuals. The overall population trend is uncertain, as some populations are decreasing, while others are increasing or have unknown trends.

Pied-billed grebe

Podilymbus podiceps

(Photo from Wikipedia)

Common name:

pied-billed grebe (en); mergulhão-caçador (pt); grèbe à bec bigarré (fr); zampullín de pico grueso (es); bindentaucher (de)

Taxonomy:

Order Podicipediformes

Family Podicipedidae

Range:

The pied-billed grebe is present in much of the American continent, from south-central Canada in the north, through the United States, Central America and the Caribbean, into the northern countries of South America. They are also present along the Pacific coast of Ecuador and Peru, and in the temperate parts of South America, in Argentina, Chile, Uruguay, Paraguay, south-east Bolivia and southern Brazil.

Size:

These birds are 31-38 cm long and have a wingspan of 45-62 cm. They can weigh up to 570 g.

Habitat:

They breed at low elevations in ponds, lakes, marshes and slow moving streams, choosing areas with emergent vegetation to anchor their nests. During winter they can be found in both fresh and salt water, and use more open waters. In migration they may be found at higher elevations, even in mountain lakes.

Diet:

Their bill is adapted to crushing large crustaceans and they often eat crayfish. The diet also includes insects, small fish and amphibians. They are know to eat their own feathers to avoid injuries from swallowing bones and shells.

Breeding:

Both parents build a bowl-shaped nest in a platform of floating vegetation. The female lays 5-7 bluish-white eggs which are incubated by both parents for 23 days. When they leave the nest unattended, the parents cover the eggs with plant material. Soon after hatching the chicks can swim on their own, but the parents will feed them and even carry them on their backs for the first few weeks.

Conservation:

IUCN status - LC (Least Concern)

With an extremely wide breeding range and a stable population, this species is not threatened at present.