The Tropical Shearwater has five subspecies.
P.b. bailloni (described above) is found in the Mascarene Islands, especially Europa Island and La Reunion.
P.b. nicolae is found in Seychelles, Maldives and Chagos Archipelago.   
P.b. colstoni occurs on Aldabra Islands, but it is genetically similar to “nicolae”.
P.b. dichrous is found in tropical Pacific Ocean. It breeds from Palau and Marianas E to Gambier Island.
This race is very small, with dark margins to the underwings and dark undertail-coverts. There are some dirty patches on breast sides and variable white sides to the rump.
P.b. gunax occurs in SW Pacific Ocean and breeds on Vanuatu.    
This one is slightly larger, with bigger bill than “dichrous”. It is blacker on the upperparts and the crown is darker. The undertail-coverts are dark.

The Tropical Shearwater is a marine bird, but it breeds in colonies on islands, rocky islets and coral reefs, on sea cliffs and slopes, especially earthy slopes with some vegetation.
Depending on the range, these birds can be seen at various elevations, up to 1,700 metres on La Reunion, but usually between 400 and 900 metres.
Outside this period, it is pelagic and remains in offshore waters.

The Tropical Shearwater is typically silent at sea. However, at the colonies, they have a large repertoire of sounds given in flight over the colony, or from the ground, including from inside the nest-burrow.
The calls include series of rapidly repeated crows, coos and croons (the latter lasting 2-3 seconds and audible over 100-500 metres). We can also hear howls, cackles, trills, moans and various other types of sounds.
Calling is more intense at the beginning of the breeding season, especially during the night, but it is rare during the day.

The Tropical Shearwater feeds on small fish, small crustaceans and squid.
The prey are caught with the bill. While foraging, it sometimes dives under the surface, but it also floats on the water before submerging to catch the prey. It also forages by fluttering just above water surface, or by plucking prey from just below the surface. It may dives during several seconds, up to 15 metres depth, but sometimes up to 35 metres.  

The Tropical Shearwater nests in rock-crevices, self-excavated burrows and other ground cavities. It breeds in colonies of low density and often in small numbers.
Sexual activities usually take place inside the burrow or the nest-cavity. The courtship displays are simple, consisting largely of “billing” and mutual preening. Both mates may engage in series of long calls.  
Then, following an effective copulation, both mates return to the sea to regain weight. However, the pre-laying exodus is usually short and may only involve the female (but more studies are required).

The Tropical Shearwater adult is probably largely sedentary as they are often observed between 80 and 300 kilometres of their breeding grounds.
Immatures are probably more dispersive.

In flight, the Tropical Shearwater alternates rapid wingbeats and long glides while at sea.

The breeding season varies, depending on the range. It occurs year-round close to the equator, and in summer at higher elevations.
The Tropical Shearwater breeds on islands, islets or coral reefs, usually on sea cliffs or earthy slopes. This species nests in cavities, from rock-crevices or hollows in the ground, to self-excavated burrows (60-200 centimetres long). No vegetation is used in the nest.

The female lays a single white egg. Both mates incubate during 50 days. At hatching, the downy chick is greyish above and white below. It is usually brooded for the first week (3-7 days). It is fed by both parents.
It fledges about 75 days after hatching (62-100 days) and weighs about 250 grams. It will be sexually mature at 8 years.  

The chick flies out to the sea several days after adult’s desertion. It has to find its way to the sea alone, with no flying experience. When the colonies are far from the sea, the young birds are often taken by predators such as gulls, skuas, corvids, and raptors, and sometimes introduced mammals (rats and cats).
But the fledging success may reach 68%.

The Tropical Shearwater is described as widespread and locally abundant. The birds may be vulnerable to human exploitation (chicks are taken for food on Reunion). They are killed by introduced mammals such as rats, cats and mongooses. They are affected by habitat destruction involving local extinctions. However, the species is not globally threatened and the Tropical Shearwater is currently evaluated as Least Concern.

Fr: Puffin de Baillon
Ang: Tropical Shearwater
All: Tropensturmtaucher
Esp: Pardela tropical
Ita: Berta di Baillon
Nd: Baillons Kleine Pijlstormvogel
Sd: tropiklira


Jean-Claude Jamoulle
A la rencontre des Oiseaux

Text by Nicole Bouglouan


HANDBOOK OF THE BIRDS OF THE WORLD vol 1 by Josep del Hoyo-Andrew Elliot-Jordi Sargatal - Lynx Edicions - ISBN: 8487334105

Guide des Oiseaux de mer de Peter Harrison – Editeur: Broquet Lavoie - ISBN-10: 2890004090 – 448 pages

OISEAUX des ÎLES DE L’OCÉAN INDIEN De Ian Sinclair – Editeur: Penguin Random House South Africa, 2013 – ISBN: 1775840727, 9781775840725 – 263 pages

Avibase (Denis Lepage)

Birdlife International

Birds of the World


Biodiversity Explorer

Indian birds

Foraging ecology and breeding biology of Wedgetailed shearwater (Puffinus pacificus) and Tropical shearwater (Puffinus bailloni) on Aride Island Nature Reserve: tools for conservation (Seychelles)

What Bird-The ultimate Bird Guide (Mitchell Waite)

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Tropical Shearwater 
Puffinus bailloni

Procellariiformes Order – Procellariidae Family

The Tropical Shearwater was formerly a subspecies of Audubon’s Shearwater, but it is now a full species with five subspecies.
It is found in W Indian Ocean, from E Africa to S India, and in the Pacific Ocean from SE Japan to French Polynesia.
It is usually seen in offshore waters, but it remains near the coasts during the breeding season. The colonies are established on islands and coral reefs. Like numerous Procellariidae, it nests in burrow or rock crevices on sea cliffs and earthy slopes. It feeds on fish, crustaceans and squid caught in the water, both at the surface and underwater.     
The Tropical Shearwater is widespread to locally abundant, and currently, the species is not globally threatened.

Length: 27-33 cm
Wingspan: 64-74 cm
Weight: 165-259 g

The Tropical Shearwater is small with short, broad wings and long, rounded tail.
It has dark brown plumage above, including on the head.
On the underparts, lower cheeks and sides of foreneck, chin and throat are white. The blackish-brown breast sides are barred whitish. Rest of underparts is white, but the central undertail-coverts are blackish.
On the underwing, lesser coverts and carpal edges of coverts are blackish. The underside of the flight-feathers is dark greyish.  

On the head, forehead, crown and nape are black-brown. Lower cheeks, chin, throat and lower neck are white.
The black bill is slightly hooked at tip. The eyes are dark brown. Legs and webbed feet are pinkish, but the feet show blackish outer side. 

The female resembles male but she is slightly smaller.

The juvenile resembles adult but with black to very dark brown upperparts.