Identifying Palau's seabirds
Palau supports important breeding colonies representing all the major groups of seabirds.
Some colonies are of global importance so monitoring health and threats would be helpful.
There are also many more pelagic (sea-going) species that pass through on seasonal migrations between hemispheres, or disperse from other tropical breeding grounds.
Click on the links below to skip to information for a specific group of birds.
Sooty Terns and Bridled Terns : Grey-backed Terns and Greater Crested Terns : Brown Noddies and Black Noddies : Blue-billed White Terns and Black-naped Terns: Great and Lesser Frigatebirds : Migrant terns of wetlands Boobies : Tropicbirds : Sea-going seabirds (Northern Storm-petrels) : Sea-going seabirds (Southern Storm-petrels) : Sea-going seabirds (Albatrosses) : Sea-going seabirds (Petrels) : Sea-going seabirds (Shearwaters) : Other migrants infrequently recorded
How to identify closely related species
Some seabirds in Palau look very similar. These are some key differences that will help you tell them apart.
Sooty Terns and Bridled Terns
Sooty Terns
- Black and white as adults, all black with white speckling in juveniles.
- Feed in flocks.
- Colonial nesters on the surface of the ground.
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| Adult Sooty Tern Marinha do Brasil, CC BY-SA 2.0 | Juvenile Sooty Tern Toby Hudson - Own work, CC BY-SA 3.0 | Sooty Tern colony Duncan Wright, USFWS - Own work, Public Domain | Chick Duncan Wright, USFWS - Own work, Public Domain |
Bridled Terns
- Dark grey to black above with white above eye tapering narrowly backwards.
- Feed alone near near the shore.
- Nest in crevices.
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| Bridled Tern in breeding plumage, Rock Islands Charles J. Sharp - Own work, CC BY-SA 4.0 | Juvenile Bridled Tern Sputnikcccp at the English-language Wikipedia, CC BY-SA 3.0 | Composite image Richard Crossley - The Crossley ID Guide Britain and Ireland, CC BY-SA 3.0 | Adult with egg (under stair) Calistemon - Own work, CC BY-SA 4.0 |
Grey-backed Terns and Greater Crested Terns
Both species nest in loose colonies
Grey-backed Terns
- Migratory
- Dark grey back and wings, black head, white underparts, fine bill.
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| Grey-backed Tern on egg Duncan Wright - USFWS Hawaiian Islands NWR, Public Domain |
Greater-crested Terns
- Huge, grey and white, black cap, and a large yellow bill.
- Often feed close to shore.
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| Greater Crested Tern mattf1996 - iNaturalist, CC BY 4.0 | Adult with chick Borhan Pak - Own work, CC BY-SA 4.0 | Immature Greater Crested Tern Charles J. Sharp - Own work, CC BY-SA 4.0, | With Little Tern Jimfbleak - derived from work by Glen Fergus, CC BY-SA 2.5 |
Brown Noddies and Black Noddies
Brown Noddies
- Have longer bodies with brown coloured bodies and a creamy coloured cap.
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| Brown Noddy Charles J. Sharp - Own work, CC BY-SA 4.0 | Adult with chick Charles J. Sharp - Own work, CC BY-SA 4.0 | Brown Noddies Charles J. Sharp - Own work, CC BY-SA 4.0 | With nesting material, Palau Charles J. Sharp - Own work, CC BY-SA 4.0 |
- More compact, blackish (darker than Brown Noddies) with a white cap.
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| Black Noddy Gregg Yan, CC BY-SA 3.0 | In the Rock Islands Charles J. Sharp - Own work, CC BY-SA 4.0 | In the Rock Islands Charles J. Sharp - Own work, CC BY-SA 4.0 | Adults nesting, with chicks Nogwater from Oak Park, CA, USA, CC BY-SA 2.0 |
Blue-billed White Terns and Black-naped Terns
Blue-billed White Terns
- All white with a blue and black coloured bill.
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| Blue-billed White Tern Charles J. Sharp - Own work, CC BY-SA 4.0 | Juvenile Monica Gruber, Pacific Biosecurity | Adult Forest & Kim Starr, CC BY 3.0 |
Black-naped Terns
- All white with a striking black band on the back of the head.
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| Black-naped Tern Mvbellad - Own work, CC BY-SA 4.0 | In breeding plumage Charles J. Sharp - Own work, CC BY-SA 4.0 |
Great and Lesser Frigatebirds
Great Frigatebirds
- Male is all black (no white underwing).
- Female is pied (patches of different colors), white breast.
- Juvenile has a rust-colored head and breast.
- Breeds in Palau.
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| Male Great Frigatebird displaying Charles J. Sharp - Own work, CC BY-SA 3.0 | Male, showing feathers on gular sac Charles J. Sharp - Own work, CC BY-SA 3.0 | Chick D. Gordon E. Robertson - Own work, CC BY-SA 3.0 | Breeding pair Charles J. Sharp - Own work, CC BY-SA 3.0 |
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| Chick begging from female parent Duncan Wright - USFWS, Public Domain | Juvenile male in flight Peterwchen - Own work, CC BY-SA 4.0 | Female in flight Aviceda at English Wikipedia, CC BY 3.0 |
Lesser Frigatebirds
- Larger than Great Frigatebird, glossy.
- Male is all black with narrow white bar in underwing.
- Female is pied (patches of different colors).
- Juvenile has a rust-colored head.
- Might breed in Palau.
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| Male Lesser Frigatebird Ariefrahman - Own work, CC BY-SA 4.0 | Male Lesser Frigatebird Ariefrahman - Own work, CC BY-SA 4.0 |
Migrant terns of wetlands
Whiskered, White-winged, Little and Common Terns pass through Palau on migration between eastern Asia and Australasia.
They are more likely to be in intertidal areas and wetlands than on the ocean.
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| Whiskered Tern in summer breeding colors Charles J. Sharp - Own work, CC BY-SA 4.0 | Whiskered Tern in non-breeding plumage Charles J. Sharp - Own work, CC BY-SA 4.0 | White-winged Black Tern Nrg800 - Own work, CC BY-SA 4.0 | Little Tern PetroKaterynych - Own work, CC BY 4.0 | Common Tern MPF - Own work, CC BY-SA 4.0 |
Boobies
Red-footed Boobies have red feet!
- Two forms (dimorphic); pied and all dark.
- Nest in trees.
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| Pied form of Red-footed Booby Gregg Yan, CC BY-SA 3.0 | Brown form, adult male Charles J. Sharp - Own work, CC BY-SA 3.0 | Pied form Eowes - Own work, CC BY-SA 4.0 | Nesting pair Mark Sullivan/NOAA, Public Domain | Juvenile Eowes - Own work, CC BY-SA 4.0 |
Brown Boobies are chocolate brown above, white below
- Juveniles are darker
- Nest on the ground.
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| Adult Brown Booby Danilo da Castro - Own work, CC BY-SA 3.0 | Adult male Andreas Trepte - Own work, CC BY-SA 4.0 | Adult female Charles J. Sharp - Own work, CC BY-SA 4.0 | Breeding pair, Charles J. Sharp - Own work, CC BY-SA 4.0 |
Masked Boobies are large pied boobies with black mask over face.
- May be a potential visitor to Palau?
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| Adult Masked Booby Forest & Kim Starr, CC BY 3.0 | seabamirum - Flickr, CC BY 2.0 | Breeding pair and chick Casliber - Own work, CC BY-SA 4.0 | Juveniles Dr. Dwayne Meadows, NOAA, Public Domain | Courting display U.S. Fish and Wildlife Service Headquarters, CC BY 2.0 |
Tropicbirds
White-tailed Tropicbirds are white with yellow bill and a black line in the wing (speckled in juveniles).
- White tail streamers.
- Nest in tree crevices
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| White-tailed Tropicbird Marion Schneider & Christoph Aistleitner - Own work, Public Domain | kansasphoto - Flickr, CC BY 2.0 | HarmonyonPlanetEarth, CC BY 2.0 |
Red-tailed Tropicbirds are white with a red bill.
- Red tail streamers.
- Nest on the ground.
- Visitor to Palau.
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| Red-tailed tropicbird Francesco Veronesi, CC BY-SA 2.0 | Circling courtship Peterwchen - Own work, CC BY-SA 4.0 | Juvenile SurreyJohn - Own work, CC BY-SA 4.0 | DickDaniels - Own work, CC BY-SA 3.0 |
Sea-going seabirds (Northern Storm-petrels)
Matsudaira’s Storm-petrel is dark grey with conspicuous white wing bars.
- Migratory
- Listed as Vulnerable.
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| Matsudaira’s Storm-petrel Tony Morris, CC BY-SA 2.0 |
Leach’s Storm-petrel is dark grey with conspicuous white wing bars and white rump.
- Migratory
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| Leach’s Storm-petrel Alexis Lours - Own work, CC BY 4.0 | rawcomposition - iNaturalist, CC0 |
For identification from boats on the ocean, it can help to video and examine the footage on a computer screen later.
Sea-going seabirds (Southern Storm-petrels)
Polynesian Storm-petrels are black above with conspicuous white upper tail, and white below with black collar, white chin.
- Possible visitor to Palau.
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| Polynesian Storm-petrel James Eaton - iNaturalist, CC0 | Polynesian Storm-petrel James Eaton - iNaturalist, CC0 |
Wilson's Storm-petrels are black with white rump, pale wing bars.
- Visitor in the Southern winter.
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| Wilson's Storm-petrel JJ Harrison - Own work, CC BY-SA 3.0 | Showing the distinctive markings across the upper wing Ethan Rudnitsky - Own work, CC BY-SA 4.0 | Pattering across water during feeding Ethan Rudnitsky - Own work, CC BY-SA 4.0 |
Sea-going seabirds (Albatrosses)
Black-footed Albatrosses are large and dark with a whitish face
- Visit Palau seas from their North Pacific breeding islands.
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| Black-footed Albatross Jlfutari, CC BY-SA 3.0 | Black-footed Albatross dancing Brocken Inaglory, CC BY-SA 3.0 |
Other albatrosses, e.g. the much whiter Laysan Albatrosses, are potential visitors
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| Laysan Albatross DickDaniels - Own work, CC BY-SA 3.0 | Laysan Albatross landing on water USFWS, Public Domain | With chick Ryan Hagerty USFWS, Public Domain | DickDaniels - Own work, CC BY-SA 3.0 |
Sea-going seabirds (Petrels)
Several petrel species migrate through Palau ocean waters.
From the New Zealand region:
Mottled Petrels
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| Mottled Petrel JJ Harrison - Own work, CC BY-SA 3.0 |
Black-winged Petrel
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| Black-winged Petrel Christopher Watson, CC-BY-SA 3.0 | Aviceda - Own work, CC BY-SA 3.0 |
Cook's Petrels
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| Cook's Petrel JJ Harrison - Own work, CC BY-SA 3.0 | Aviceda, CC BY 3.0 |
From the North Pacific:
White-necked Petrels
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| White-necked Petrel JJ Harrison - Own work, CC BY-SA 3.0 | JJ Harrison - Own work, CC BY-SA 3.0 |
Bulwer’s Petrels
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| Bulwer’s Petrel Jérémie Silvestro, CC BY-SA 4.0 | Roosting in a seawall Duncan from Wellington, NZ, CC BY-SA 2.0 |
From the East Pacific:
Juan Fernandez Petrels
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| Juan Fernandez Petrel Christoph Moning - iNaturalist, CC BY 4.0 |
They are tricky to identify, so take photos and videos.
Sea-going seabirds (Shearwaters)
Migratory Shearwaters numbers peak in March-May and August-October.
Wedge-tailed Shearwaters
- Angular wings, dark or pied forms.
- Potential Palau resident.
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| Wedge-tailed Shearwater Forest & Kim Starr, CC BY 3.0 | Pale and dark forms side-by-side Duncan Wright, USFWS - Own work, Public Domain | Duncan Wright - USFWS, Public Domain |
Streaked Shearwaters
- Streaked body.
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| Streaked Shearwater Kanachoro - Own work, CC BY-SA 3.0 | 孫鋒 林 - Flickr, CC BY-SA 2.0 |
Short-tailed Shearwaters
- Black.
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| Short-tailed Shearwater NPS - NPGallery, Public Domain | JJ Harrison - Own work, CC BY-SA 3.0 |
Sooty Shearwaters
- Black with silvery underwing flash.
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| Sooty Shearwater JJ Harrison - Own work, CC BY-SA 3.0 | Sabine's Sunbird - Own work, CC BY-SA 3.0 | Walking on water Sarah Amirani, CC BY-SA 4.0 |
Flesh-footed Shearwaters
- Large, blackish brown.
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| Flesh-footed Shearwater - no rights reserved, iNaturalist, CC0 | Duncan, CC BY-SA 2.0 |
Buller’s Shearwaters
- Large, pied.
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| Buller’s Shearwater JJ Harrison - Own work, CC BY-SA 3.0 | Izzy Lopez - Own work, CC BY 4.0 |
Other migrants infrequently recorded
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| Great Cormorant - State of Palau's Birds 2021 | Black-headed Gull - State of Palau's Birds 2021 | Gull-billed Tern - Ann Kitalong State of Palau's Birds 2020 | Pomerine skua - Glenn McKinlay State of Palau's Birds 2019 |
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| State of Palau's Birds 2021 |