Africa Wild Bird Book

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Grey-backed Storm-petrel Garrodia nereis
Order: Procellariiformes. Family: Hydrobatidae



Description
Wingspan: 39 cm. Length: 16-19 cm. Weight: 21-44 g. Grey-backed Storm Petrels are compactly built, with short tails and legs, with the feet barely reaching past the tip of the tail. In flight they flutter more and use their legs less than other storm petrels, but at times do run off the surface of the water. Upperparts black with grey wash to back and wing coverts, grey tail and rump. Tail has a black terminal band. Appears dark hooded. Underparts have black chest, white belly and black undertail. Iris and bill black, the latter whitish towards the base of lower mandible; legs and feet dark brown.
Similar species: The species is readily distinguishable from the other Storm Petrels by its diminutive size and the absence of white on the rump. May be confused with Black-bellied Storm Petrel, which has a dark-hooded appearance due to its dark head and white belly. The thick black median ventral of Black-bellied, as wall as the entirely dark underside of the primaries and undertail coverts, the all dark back, and the white rump band quickly eliminate confusion with Gray-backed. Both White-bellied and Black-bellied storm-petrels also show little foot projection beyond the tail.

Distribution
Southern Oceans. The Grey-backed Storm Petrel has a circumpolar distribution in the subantarctic, breeding on islands from the Falkland Islands (Islas Malvinas) in the south-west Atlantic east to the Chatham Islands (New Zealand). Individuals can winter nearer to the continents.

Habitat
Pelagic. Often found at sea near dislodged, floating kelp or other drifting material.

Diet
Immature barnacles, crustaceans, small squid & small fish. It catches prey mostly by pattering over the surface whilst in flight, but also by dipping and shallow plunging.

Breeding
The Grey-backed Storm Petrel nests in colonies or alone, usually on or near ground in dense tussac grassland or other vegetation on flat, sloping or occasionally steep ground. Its breeding season starts in October or November. Single egg is laid and incubation lasts c. 45 days. Fledging time unknown, but chicks on the wing in March-April.

Status
Extreme vagrant to the region with two records to date. Uncommon in offshore waters at Gough, Marion and Prince Edward islands.

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Grey-backed Storm-petrel Garrodia nereis





Links:
NEWMAN'S VOELS VAN SA (8ste UIT)

[Dewi]

046. Black-bellied Storm-petrel Fregetta tropica (Swartstreepstormswael).
Order: Procellariiformes. Family: Hydrobatidae



Description
24 cm. Large blackish storm-petrel.
Upperparts black, darker on the wings and tail, with pale brown wing panels and white rump. Underparts have white on the central underwing and belly with a black midline running through, although this can be variable and even absent in some birds. Black bill, legs and feet. Black Iris.
Similar species: Larger than Wilson's Storm Petrel, from which it differs in having extensive white on the underwings and a white belly with a black line down the centre.

Distribution
Circumpolar between the Equator & Antarctic circle, but found further North in the Indian Ocean. Found offshore throughout the region, but commoner in deeper waters. Breeds at Shetland Island, the Orkneys, South Georgia, the Sandwiches, Bouvet, the Prince Edwards, the Crozets, Kerguelen, Auckland and Antipodes, dispersing across the southern Ocean to tropical and sub-tropical areas, including much of southern African waters while largely excluding the more shallow continental shelf.

Habitat
Pelagic.

Movements and migrations
It is mainly recorded passing through southern Africa in the short period from late April to early June (moving north to its non-breeding grounds) and from mid September to mid November (heading back to its breeding colonies).Diet: Poorly known. Feeds on Copepods, squid, small fish & offal.

Diet
It mainly eats fish, squid, small crustaceans, scraps and offal, doing most of its foraging by dipping its head into the sea to grab prey, often in association with other seabirds, seals and whales.

Breeding
Breeds on Sub-antarctic islands in loose colonies. Nests in holes in rocky screes or burrows. Lays one egg, November-December. Incubation lasts between 38-44 days. Chicks fledge after 65-71 days.

Status
Uncommon winter visitor.

[Dewi]

046. Black-bellied Storm-petrel Fregetta tropica (Swartstreepstormswael).



Links:
Sasol
Identification of ‘black-and-white’ storm-petrels
Trevor Hardaker Photos

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042. European Storm-petrel Hydrobates pelagicus (Europese Stormswael)
Order: Procellariiformes. Family: Hydrobatidae



Description
This Storm-Petrel is a small bird 15–16 cm in length with a 38–42 cm wingspan. The smallest seabird in the region. Dark glossy black plumage. White rump. White bar on the under-wing. Dark iris. Dark hooked bill. Dark short legs and webbed feet, that do not project past the square-ish tail when flying. Its tail is not forked, unlike Leach's petrel. It has a nasal salt gland connected to a fused nostril, which is used to expel excess salt after drinking seawater. Both sexes are similar.
Juvenile shows more conspicuous bar on the upperwing.
Similar species: It can be distinguished from Leach's Storm Petrel and Wilson's Storm Petrel by its smaller size, different rump pattern and flight behaviour. Blackish-brown plumage is slightly darker than Wilson's Storm-petrel.

Distribution
Breeds in Iceland, western Europe and possibly North Africa, heading south in the non-breeding season to the coastline of Africa from Mauritania to southern Africa. Here it is common along the coastline of Namibia and South Africa up to East London, less common further out to sea, while more scarce further north-east through KwaZulu-Natal to Mozambique.

Habitat
Pelagic when not breeding and rarely seen from shore, only seen on land after being storm-driven.

Movements and migrations
It leaves its European breeding grounds from August-October, migrating along the coast of western Europe and Africa and eventually arriving in southern Africa in September. Its numbers peak in the region from November-March, leaving for its breeding grounds in May.

Diet
It mainly eats crustaceans and small fish, doing most of its foraging by immersing head or its entire body in the sea in order to grab prey. It is readily seen from ships, which it will follow. In flight it flutters over the water, feeding with its wings held up in a 'V' with feet pattering across the waves. At sea it often feeds in flocks.

Breeding
It breeds on inaccessible islands in the north Atlantic and western Mediterranean. A truly monogamous species, pairs of European Storm-Petrels stay together for life once they have bonded. After mating, a single large white egg is laid in a rock crevice or burrow in a colony, from May or June. The European Storm Petrel only emerges from its concealed nest during the darkest hours of night, to reduce predation by gulls and skuas and to keep the location of the burrow hidden. The adult birds share the incubation duties and, after approximately 41 days, the chick hatches as a silvery-grey ball of fluffy feathers. Should the chick survive fledging, it has a long life expectancy of over 20 years, reaching sexual maturity after four or five years. Due to the egg weighing up to 25 %of the female’s weight, and the lengthy incubation and fledging period, raising young is a costly investment for the breeding pair.

Call
Silent at sea. Listen to Bird Call.

Status
Common summer visitor especially off Namibia; present end Sept-May, peaking Nov-Mar. Also recorded east to East London, less abundant of KwaZulu-Natal and Mozambique. The European Storm Petrel is classified as Least Concern (LC) on the IUCN Red Lis-p

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042. European Storm-petrel Hydrobates pelagicus (Europese Stormswael)



Links:
Sabap2: http://sabap2.adu.org.za/spp_summary.ph ... &section=3
Sasol, Oiseaux Oiseaux net: http://www.oiseaux-birds.com/card-europ ... etrel.html
Identification of ‘black-and-white’ storm-petrels
Trevor Hardaker Photos

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043. Leach's Storm-petrel Oceanodroma leucorhoa (Swaelstertstormswael)
Order: Procellariiformes. Family: Hydrobatidae



Description
A largeish slender Storm-petrel with long, narrow wings. Upperparts black-brown with pale wing-panels and distinct white v on the rump. Tail is long and forked. Underparts black-brown. Bill, legs, and feet are black. Feet do not extend beyond tail in flight.
Similar species: Wilson's Storm Petrel has a white conspicuous patch on rump; tail squared; yellow legs projecting beyond tail in flight.

Distribution:
Northern Hemisphere oceans, but extends South along the coasts of Western Africa to the Cape. Breeds on islands in the North Pacific and North and South Atlantic Oceans, with northern breeders heading south to the tropics and subtropics in the non-breeding season. It is a common summer visitor to southern African waters off the western and southern coast, although it also breeds in very small numbers on Dassen, Dyer and Dassen Island in the Western Cape and St. Croix Island in the Eastern Cape.

Habitat
Pelagic. It typically occurs in oceanic waters and is scarce over the shelf edge and rare inshore.

Movements and migrations
It is both a breeding and non-breeding migrant to southern Africa, arriving around September-November and departing in the period from February-April.

Diet
It mainly eats small fish, squid, planktonic crustaceans, copepods and offal, foraging both in the day and at night. Most prey are caught by dipping its head into the water and extracting the animal, sometimes following marine mammals to feed on food scraps or faeces.

Breeding
The total South African breeding population is thought to be about 25 pairs. The nest is excavated by the female, consisting of a burrow ending in a nest chamber which is lined with small pieces of woody vegetation and sometimes grass. It may also use a rock crevice or burrow dug by another species. Egg-laying season probably peaks in November. It lays a single egg, which is incubated by both sexes for about 38-42 days, sometimes up to 50 days if the nest was for some reason left unattended for several days. The chick is brooded for the first 4-6 days its life and by 55 days or so it is already roughly twice the adults mass. By the time it fledges at 61-70 days old its weight has decreased to only slightly more than that of its parents, at which point it becomes independent.

Status
Uncommon visitor off the West coast during Summer months. Recently colonised Dyer Island off the West coast and now breeding in small numbers. Endangered in South Africa, where its population is small and threatened by predation of Domestic cats and Kelp gulls at its colonies.

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043. Leach's Storm-petrel Oceanodroma leucorhoa (Swaelstertstormswael)



Links:
Species text in The Atlas of Southern African Birds: http://sabap2.adu.org.za/docs/sabap1/043.pdf
Sasol
Avian Demography Unit: Leach's Storm Petrel breeding in South Africa
Identification of ‘black-and-white’ storm-petrels

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ORDER PODICIPEDIFORMES Family Podicipedidae (Grebes)

A grebe is a member of the order Podicipediformes, a widely distributed order of freshwater diving birds, some of which visit the sea when migrating and in winter. This order contains only a single family, the Podicipedidae, containing 22 species in 6 extant genera.
Grebes are small to medium-large in size, have lobed toes, and are excellent swimmers and divers. However, although they can run for a short distance, they are prone to falling over, since they have their feet placed far back on the body.
Grebes have narrow wings, and some species are reluctant to fly; indeed, two South American species are completely flightless. They respond to danger by diving rather than flying, and are in any case much less wary than ducks. Extant species range in size from the Least Grebe, at 120 grams and 23.5 cm, to the Great Grebe, at 1.7 kg and 71 cm.
However, the North American and Eurasian species are all, of necessity, migratory over much or all of their ranges, and those species that winter at sea are also seen regularly in flight. Even the small freshwater Pied-billed Grebe of North America has occurred as a transatlantic vagrant to Europe on more than 30 occasions.
Bills vary from short and thick to long and pointed, depending on the diet, which ranges from fish to freshwater insects and crustaceans. The feet are always large, with broad lobes on the toes and small webs connecting the front three toes. The hind toe also has a small lobe. Recent experimental work has shown that these lobes work like the hydrofoil blades of a propeller.
Grebes have unusual plumage. It is dense and waterproof, and on the underside the feathers are at right-angles to the skin, sticking straight out to begin with and curling at the tip. By pressing their feathers against the body, grebes can adjust their buoyancy. Often, they swim low in the water with just the head and neck exposed.
In the non-breeding season, grebes are plain-coloured in dark browns and whites. However, most have ornate and distinctive breeding plumages, often developing chestnut markings on the head area, and perform elaborate display rituals. The young, particularly those of the Podiceps genus, are often striped and retain some of their juvenile plumage even after reaching full size.
When preening, grebes eat their own feathers, and feed them to their young. The function of this behaviour is uncertain but it is believed to assist with pellet formation, and to reduce their vulnerability to gastric parasites.
Grebes make floating nests of plant material concealed among reeds on the surface of the water. The young are precocial, and able to swim from birth.

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Species indigenous to southern Africa:

ORDER PODICIPEDIFORMES
Family Podicipedidae (Grebes)
Tachybaptus ruficollis Little Grebe 008
Podiceps cristatus Great Crested Grebe 006
Podiceps nigricollis Black-necked Grebe 007