10

Bridled Tern (Onychoprion anaethetus) Alternate name(s): "Brown-winged Tern", "Dog Tern" Size: 30-32 cm; wing span ca. 75-80 cm Body mass: 95-150 g Wing loading [g/cm2]: 0.18-0.19

Australia: Family Group 10 Family Group 10 Table Brown Skua South Polar Skua Arctic Jaeger Pomarine Jaeger Long-tailed Jaeger Pacific Gull Kelp Gull Silver Gull Crested Tern Lesser Crested Tern Caspian Tern Australian Tern Gull-billed Tern White-fronted Tern Black-naped Tern Roseate Tern Antarctic Tern Arctic Tern Common Tern Little Tern Fairy Tern Whiskered Tern White-winged Black Tern Grey Ternlet White Tern Sooty Tern Bridled Tern Aleutian Tern Common Noddy Black Noddy Thumbnails page Family group table Index of bird names Habitat pages Key plants Birds home page

Similar species

Description     Classification     Distribution     Sightings     Photos     Breeding     Nest     Eggs     Behaviour     Food     Call/s

Physical description Click here for a physical description Bridled Terns are medium-sized terns. They have a black cap that also covers the entire nape of the neck, connecting to the dark-grey mantle and wings. The black eyes are set into a black eye stripe. Frons and front (throat, chest, belly, vent) are all white. Bill, legs and feet are black. The underwings are white, except for a broad dark-grey trailing edge. Juvenile Bridled Terns have a light-grey frons and front and a mottled grey cap. The upperwings and mantle are scalloped dark-grey with brownish edge lining. In breeding plumage the white supercilium reaches well behind the eye. Twitcher's tip Compared to Sooty Terns, the Bridled Tern is somewhat lighter in appearance and the supercilium is longer.

Taxonomy, classification See Bridled Tern at Wikipedia .

Range, habitat, finding this species Click here for information on habitat and range The overall distribution of this species can be assessed, and specific locations where birds have been spotted can be found, based on individual sighting reports submitted by birdwatchers to ebird.org . The global distribution of the Bridled Tern is available HERE . Bridled Terns are a global species, with several races across various continents. Nominate race "anaethetus" populates the eastern Indian Ocean and the Pacific Ocean and the south-eastern Asian waters in between, including the North-Australian seaboard. Race "antarcticus" is found in the Red Sea, the Persian Gulf and the western Indian Ocean. Race "melanopterus" is found in the Caribbean and in western Africa, while race "nelsoni" populates the West coast of Mexico and central America. According to most sources, in Australia only nominate race "anaethetus" is found. They migrate to Australia from the North, populating much of the Australian seaboard and continental shelf. In addition to the entire North coast towards the West their range extends to near Esperance, WA. Along the East coast their range ends near the QLD/NSW border. They are not found anywhere inland.

Sightings Click here for sighting information Race "anaethetus" M. Mearns reports finding Bridled Terns, race "anaethetus", nesting on Lady Elliot Island, off the QLD coast near Agnes Water, in January 2006 and again in January 2016. H. Mouritsen reports spotting Bridled Terns, race "anaethetus", on One Tree Island, Capricornia Cays NP, near Rockhampton, QLD, in January 2011. J. Greaves reports spotting Bridled Terns, race "anaethetus", on Penguin Island, near Rockingham, WA, in March 2016. C. Pears also found Bridled Terns, race "anaethetus", on Penguin Island, near Rockingham, WA, in October 2022. V. Collins report finding Bridled Terns, race "anaethetus", on Penguin Island, Rockingham, WA, in January 2017, where they were breeding at the time. M. Eaton reports finding Bridled Terns, race "anaethetus", on Lady Musgrave Island, off the QLD coast near Agnes Water, in September 2017. Others were found on Michaelmas Cay, QLD, in October 2024. P. Brown found Bridled Terns, race "anaethetus", at Buffalo Creek, Darwin, NT, in January 2023 and at Stokes Hill Wharf, Darwin, NT, in March 2023. Race "antarcticus" We have spotted Bridled Terns, race "antarcticus", in Oman.

Photos

Race "anaethetus"

ADULT

PAIR

Lateral view of a pair of Bridled Terns performing their courtship dance (photo courtesy of M. Mearns)
[Lady Elliot Island, near Agnes Water, QLD, January 2016]

Lateral view of a pair of Bridled Terns performing their courtship dance (photo courtesy of M. Mearns)
[Lady Elliot Island, near Agnes Water, QLD, January 2016]

Sex unknown

BREEDING

Close-up full-frontal view of a Bridled Tern in breeding plumage (photo courtesy of P. Brown)
[Stokes Hill Wharf, Darwin, NT, March 2023]

Close-up near-lateral portrait of a Bridled Tern in breeding plumage; note that, characteristically, the upperparts (wings/back) are a lighter shade of grey than the cap and that the white supercilium extends well behind the eye (photo courtesy of J. Greaves)
[Penguin Island, near Rockingham, WA, March 2016]

Near-lateral view of a Bridled Tern in breeding plumage (photo courtesy of M. Eaton)
[Lady Musgrave Island, near Agnes Water, QLD, September 2017]

Close-up lateral view of a Bridled Tern in breeding plumage (photo courtesy of J. Greaves)
[Penguin Island, near Rockingham, WA, March 2016]

Close-up lateral view of a Bridled Tern in breeding plumage (photo courtesy of M. Mearns)
[Lady Elliot Island, near Agnes Water, QLD, January 2016]

Lateral view of a Bridled Tern in breeding plumage (photo courtesy of H. Mouritsen)
[One Tree Island, Capricornia Cays NP, QLD, January 2011]

Close-up near-dorsal view of a Bridled Tern in breeding plumage (photo courtesy of C. Pears)
[Penguin Island, near Rockingham, WA, October 2022]

Close-up near-dorsal view of two Bridled Terns in breeding plumage (photo courtesy of M. Eaton)
[Michaelmas Cay, QLD, October 2024]

Near-dorsal/dorsal view of two Bridled Terns in breeding plumage (photo courtesy of M. Eaton)
[Michaelmas Cay, QLD, October 2024]

A flock of Bridled Terns have declared this jetty their roost (photo courtesy of J. Greaves)
[Penguin Island, near Rockingham, WA, March 2016]

Lateral view of a Bridled Tern in breeding plumage in flight (photo courtesy of H. Mouritsen)
[One Tree Island, Capricornia Cays NP, QLD, January 2011]

IMMATURE/JUVENILE

Lateral view of an adult Bridled Tern (left) with a juvenile in tow (photo courtesy of M. Mearns)
[Lady Elliott Island, QLD, January 2006]

Lateral view of a juvenile Bridled Tern (photo courtesy of M. Mearns)
[Lady Elliott Island, QLD, January 2006]

Bridled Tern with chick (photo courtesy of M. Mearns)
[Lady Elliot Island, near Agnes Water, QLD, January 2016]

Bridled Tern chick (photo courtesy of M. Mearns)
[Lady Elliot Island, near Agnes Water, QLD, January 2016]

Race "antarcticus"

Photos of race "antarcticus" were taken by us in Oman.

Breeding information

Breeding season: Sep - Dec

Eggs: 1 - 3

Incubation period: 28 - 30 days

Fledging age: ca. 15 days

The breeding period listed above applied to most locations. In the Kimberley region they also breed during a second breeding season, from about April to June. In principle, Bridled Terns can breed any time of the year. They usually have 2 eggs.

Nest building: ?

Incubation: Female & male

Dependent care: Female & male

Nest

"bungobittah", "lar", "malunna", "jindi" [bundjalung] = nest [Aboriginal]

Type: Scrape

Material: Sand, stones

Height above ground: N/A

Bridled Terns lay their eggs near the high-tide line, often near shrubs or other disguising/sheltering objects.

Bridled Tern nest with a single dark-morphology egg in it (photo courtesy of M. Mearns)
[Lady Elliott Island, QLD, January 2006]

Eggs

"boyanga", "booyanga", "derinya", "dirandil", "koomura", "mirk", "ngampu", "nooluk", "pateena", "pum-pum" = Egg; "dirundirri" = eggs [Aboriginal]; "gawu" = eggs [gamilaraay]

Size: 56 x 32 mm

Colour: Brownish, with darker streaks/speckles

Shape: Tapered oval

Bridled Terns can also have lighter, more creamy-coloured, eggs with mid- to dark-brown speckles.

Dark-morphology Bridled Tern egg in a sandy/rocky scrape (photo courtesy of M. Mearns)
[Lady Elliott Island, QLD, January 2006]

Light-morphology Bridled Tern egg in a sandy scrape (photo courtesy of V. Collins)
[Penguin Island, near Rockingham, WA, March 2016]

The owner of the Bridled Tern egg shown above (photo courtesy of V. Collins)
[Penguin Island, near Rockingham, WA, March 2016]

Behaviour

Social behaviour: Communal

Mobility: Migratory/nomadic

Elementary unit: Mob/flock

Bridled Terns have a very elaborate courtship ritual, during which the birds dance, click bills and pass food.

Bridled Terns performing their courtship dance (photo courtesy of M. Mearns)
[Lady Elliot Island, near Agnes Water, QLD, January 2016]

Bridled Terns performing their courtship dance (photo courtesy of M. Mearns)
[Lady Elliot Island, near Agnes Water, QLD, January 2016]

Lateral view of two Bridled Terns squaring up to each other (photo courtesy of H. Mouritsen)
[One Tree Island, Capricornia Cays NP, QLD, January 2011]

Food, Diet

Like all terns, Bridled Terns feed on fish, which they catch with their bills just under the water surface in a steep high-speed dive from considerable height.

Call(s)/Song

For this species we have recorded the following call(s)/song. The interpretation of their meaning is our own; comments and suggestions for improvement are welcome.

bridtrn_jg_20160306.m4a	anaethetus (SW WA)	?	© JG
bridtrn_jg_20160306_2.m4a	anaethetus (SW WA)	?	© JG

More Bridled Tern sound recordings are available at xeno-canto.org .

These pages are largely based on our own observations and those of our contributors. The structure of these bird pages is explained HERE. For more salient facts on any bird species please refer to a field guide.

Would you like to contribute photos or sound recordings to this site? If interested, please CLICK HERE. Credits to contributors are given HERE.