Bristle-thighed curlew (Numenius tahitiensis)

Bristle-thighed curlew
Bristle-thighed curlew

Bristle-thighed curlew fact file

Bristle-thighed curlew description

KingdomAnimalia
PhylumChordata
ClassAves
OrderCharadriiformes
FamilyScolopacidae
GenusNumenius (1)

This medium-sized shorebird possesses a long, down curved, touch-sensitive bill; a unifying characteristic of all curlews. The curlew’s genus name Numenius means ‘of the new moon’ and refers to the long, crescent-shaped bill. It has plumage that is mostly flesh-coloured to pale brown, with darker brown broad stripes on the head, and the upperparts are spotted cinnamon and dark brown. The underparts are streaked buff, the belly and feathers under the tail are whitish, and the legs are a pale blue-grey (2) (4). Their name comes from the bristle-like extensions at the base of their legs, although these are generally inconspicuous and can only be seen when close up. Females are heavier than males and have longer wings and a shorter bill. Juveniles are similar to adults except for the presence of larger cinnamon-buff spots on the upperparts, and virtually unstreaked underparts (2).

Size
Length: 40 – 44 cm (2)
Wingspan: 82 – 90 cm (2)
Male weight: 254 – 533 g (2)
Female weight: 372 – 796 g (2)
Top

Bristle-thighed curlew biology

Breeding in the bristle-thighed curlew probably starts around May, when the bird can be found on the Alaskan tundra (2). They are monogamous birds, forming long-term bonds, and are not only faithful to a partner, but also to breeding and wintering sites, returning to the same place year after year (5). Generally, four eggs are laid into a simple, bare depression in mossy vegetation, and both sexes will incubate the eggs for about 25 days (2) (6). The chicks leave the nest shortly after hatching, and continue to receive parental care, initially from both parents, and then just the male as the female deserts the brood before the chicks fledge (2) (6). Whilst breeding, the adults aggressively defend the eggs and chicks, and often attack potential predators or perform displays to distract them (6).

After the breeding season juveniles and adults congregate on the Yukon River delta. Here they feed on berries, insects and other foods in preparation for the migration to their wintering grounds; an impressive journey in which they fly non-stop for over 4000 kilometres (2) (6). They arrive at the oceanic islands in late August to early September, where they will undergo a moult. During this moult, over 50 percent of adults become completely flightless, for a period of two weeks (2).

Whilst on their wintering grounds, the curlews are opportunistic feeders, taking crustaceans, insects, spiders, snails, small fish, scorpions and the eggs of seabirds (2) (6). They show remarkable ingenuity by using rocks to crack the thick egg shells, a rare example of tool use by birds (6). Occasionally they also feed on seabird carrion and fish regurgitated by seabirds and lizards (2).

Top

Bristle-thighed curlew range

The bristle-thighed curlew breeds on the lower Yukon River and central Seward Peninsula in western Alaska, United States. It winters on many small oceanic islands in the South Pacific, from the Marshall and Hawaiian Islands, south to Santa Cruz, Fiji, Tonga, Samoa, Marquesas, Tuamotu Island and Pitcairn Island (2).

Top

Bristle-thighed curlew habitat

During the breeding season it can be found on exposed hilly tundra. Over winter, it occurs on oceanic islands, generally in the interior amongst dense vegetation, but sometimes on sandy beaches, rocky shores, tidal mudflats and exposed reefs (2) (4).

Top

Bristle-thighed curlew status

Classified as Vulnerable (VU) on the IUCN Red List 2007 (1) and listed on Appendix II of the Convention on the Conservation of Migratory Species (CMS) (3).

IUCN Red List species status – Vulnerable

Top

Bristle-thighed curlew threats

The fairly small population of bristle-thighed curlews is believed to be declining, primarily due to the impacts of introduced predators on their wintering grounds (1). The flightless period during the moult would have evolved during a time when there were no mammalian predators on the South Pacific islands where it spends the winter. Today, with the establishment of humans on these islands, and the subsequent introduction of mammals, moulting leaves the curlew in an extremely vulnerable position. Introduced cats, dogs and possibly pigs, prey heavily on the flightless curlews, causing a significant decline in numbers (4) (6).

Hunting was a threat to this species in the past; on the Tuamotu islands it was traditionally caught for food. However, the possession and use of firearms is now restricted on these islands and therefore hunting no longer poses a significant threat (2). On their breeding grounds the curlew suffers predation by Arctic skuas, common ravens and foxes, and the expanding development of gold mines and mining roads on the Seward Peninsula is an increasing threat that could have a significant impact on this bird, due to its reliance on this small area for breeding (2) (6).

Top

Bristle-thighed curlew conservation

The bristle-thighed curlew occurs in a number of protected areas. Both the Yukon Delta and some of the remote Hawaiian Islands, are designated National Wildlife Refuges, which protects breeding grounds and several stop-over and wintering sites (4) (6). Wildlife and habitat is monitored in the Yukon Delta, but further specific monitoring of the curlew is recommended (4). Hawaii’s Comprehensive Wildlife Conservation Strategy proposes a number of conservation actions for the bristle-thighed curlew including protecting the current habitat of the curlew in Hawaii, and protecting and restoring additional wetland habitat, especially where it can be reclaimed from abandoned urban or agricultural uses (7). However, to protect this species from further declines, it is important to tackle the primary threat of introduced mammals across its wintering range.

View information on this species at the UNEP World Conservation Monitoring Centre.

Top

Find out more

For further information on the bristle-thighed curlew see:

For more information on this and other bird species please see:

Top

Authentication

This information is awaiting authentication by a species expert, and will be updated as soon as possible. If you are able to help please contact: arkive@wildscreen.org.ukTop

Glossary

Carrion
The flesh of a dead animal.
Crustaceans
Diverse group of arthropods (a phylum of animals with jointed limbs and a hard chitinous exoskeleton) characterised by the possession of two pairs of antennae, one pair of mandibles (parts of the mouthparts used for handling and processing food) and two pairs of maxillae (appendages used in eating, which are located behind the mandibles). Includes crabs, lobsters, shrimps, slaters, woodlice and barnacles.
Monogamous
Having only one mate during a breeding season, or throughout the breeding life of a pair.
Top

References

  1. IUCN Red List (May, 2008)
    http://www.iucnredlist.org
  2. del Hoyo, J., Elliott, A. and Sargatal, J. (1996) Handbook of the Birds of the World. Vol. 3: Hoatzin to Auks. Lynx Edicions, Barcelona.
  3. Global Register of Migratory Species (May, 2008)
    http://www.groms.de
  4. Birdlife International (May, 2007)
    http://www.birdlife.org/datazone/species/index.html?action=SpcHTMDetails.asp&sid=3010&m=0
  5. BirdLife International. (2001) Threatened Birds of Asia: the BirdLife International Red Data Book. BirdLife International, Cambridge, UK.
  6. National Audubon Society (May, 2007)
    http://audubon2.org/webapp/watchlist/viewSpecies.jsp?id=48
  7. Hawaii’s CWCS (May, 2007)
    http://www.state.hi.us/dlnr/dofaw/cwcs/index.html

More »Related species

Eurasian curlew (Numenius arquata)Slender-billed curlew (Numenius tenuirostris)Eskimo curlew (Numenius borealis)Little curlew (Numenius minutus)Whimbrel (Numenius phaeopus)Far eastern curlew (Numenius madagascariensis)Solitary sandpiper (Tringa solitaria)Stilt sandpiper (Calidris himantopus)

This species is featured in:

This species is affected by global climate
change. To learn about climate change
and the species that are affected,
visit our climate change pages.

Please donate to ARKive today

Help us share the wonders of the natural world. Donate today!

Sign up to our newsletter

Get the latest wild news direct to your inbox.

Get involved

ARKive relies on its media donors to donate photos and videos. Can you help? There are plenty of other ways you can get involved too!

X
Close

Image credit

Bristle-thighed curlew  
Bristle-thighed curlew

© Ron Hoff

Ron Hoff
Clinton
Tennessee
United States of America
ronhoff511@gmail.com

X
Close

Link to this photo

ARKive species - Bristle-thighed curlew (Numenius tahitiensis) Embed this ARKive thumbnail link by copying and pasting the code below.

Terms of Use - The displayed thumbnail may be used as a link from your website to ARKive's online content for private, scientific, conservation or educational purposes only. It may NOT be used within Apps.

Read more about

X
Close

MyARKive

MyARKive offers the scrapbook feature to signed-up members, allowing you to organize your favourite ARKive images and videos and share them with friends.

X
Close

Terms and Conditions of Use of Materials

Copyright in this website and materials contained on this website (Material) belongs to Wildscreen or its licensors.

Visitors to this website (End Users) are entitled to:

  • view the contents of, and Material on, the website;
  • download and retain copies of the Material on their personal systems in digital form in low resolution for their own personal use;
  • teachers, lecturers and students may incorporate the Material in their educational material (including, but not limited to, their lesson plans, presentations, worksheets and projects) in hard copy and digital format for use within a registered educational establishment, provided that the integrity of the Material is maintained and that copyright ownership and authorship is appropriately acknowledged by the End User.

End Users shall not copy or otherwise extract, alter or manipulate Material other than as permitted in these Terms and Conditions of Use of Materials.

Additional use of flagged material

Green flagged material 

Certain Material on this website (Licence 4 Material) displays a green flag next to the Material and is available for not-for-profit conservation or educational use. This material may be used by End Users, who are individuals or organisations that are in our opinion not-for-profit, for their not-for-profit conservation or not-for-profit educational purposes. Low resolution, watermarked images may be copied from this website by such End Users for such purposes. If you require high resolution or non-watermarked versions of the Material, please contact Wildscreen with details of your proposed use.

Creative commons material

Certain Material on this website has been licensed to Wildscreen under a Creative Commons Licence. These images are clearly marked with the Creative Commons buttons and may be used by End Users only in the way allowed by the specific Creative Commons Licence under which they have been submitted. Please see http://creativecommons.org for details.

Any other use

Please contact the copyright owners directly (copyright and contact details are shown for each media item) to negotiate terms and conditions for any use of Material other than those expressly permitted above. Please note that many of the contributors to ARKive are commercial operators and may request a fee for such use.

Save as permitted above, no person or organisation is permitted to incorporate any copyright material from this website into any other work or publication in any format (this includes but is not limited to: websites, Apps, CDs, DVDs, intranets, extranets, signage, digital communications or on printed materials for external or other distribution). Use of the Material for promotional, administrative or for-profit purposes is not permitted.