Belding’s yellowthroat (Geothlypis beldingi)

Description

Belding’s yellowthroat fact file

• Description
• Biology
• Range
• Habitat
• Status
• Threats
• Conservation
• Find out more
• Glossary
• References
• Print factsheet

Belding’s yellowthroat description

A relatively large, long-tailed and attractively marked New World warbler, the male Belding’s yellowthroat is an olive-green bird with bright yellow underparts, and a conspicuous black mask across the forehead and sides of the face. The mask is surrounded by a narrow yellow border, while the beak is black and the legs are pinkish. The female lacks a mask, and has an olive head, with a pale eye ring, a pale line above the eye, and a dark brown beak. The female’s underparts are yellow, washed brown on the flanks and whitish on the lower abdomen ^(2) (3). Two subspecies of Belding’s yellowthroat are recognised,Geothlypis beldingi beldingi and Geothlypis beldingi goldmani ^{(2) (3) (4) (5)}, the latter differing mainly in its duller colouration, often with a more whitish lower abdomen, and a more whitish or creamy border around the male’s mask ^{(2) (3) (4)}. Belding’s yellowthroat is very similar in appearance to the common yellowthroat, Geothlypis trichas, but can be distinguished by its larger size, longer, thicker beak, yellower underparts, and the yellow border around the male’s mask, while the female has a more distinct facial pattern and overall brighter plumage ^(2) (3).

Also known as

Peninsular yellowthroat.

Size

Length: 14 cm ^{(2) (3)}

Belding’s yellowthroat biology

Very little information is available on the biology of Belding’s yellowthroat. Described as a skulking bird of marshes and wet vegetation tangles, it is thought to forage amongst marsh vegetation and on damp ground, probably for a range of insect prey ⁽³⁾. The nest is a cup of grasses and reeds, lined with fine fibres and hairs, and located in low vegetation ^(2) (3). Up to four eggs are laid ⁽³⁾, between March and May ^(2) (6). The call of this species is a harsh djip or chek, and the song is a rich, powerful series of phrases ^(2) (3).

Belding’s yellowthroat range

Belding’s yellowthroat has a patchy distribution across the Baja California peninsula in Mexico. There is an apparent gap between the ranges of the two subspecies, with G. b. beldingi occurring in the Cape district, while G. b. goldmani is found in southern and central parts of the peninsula ^{(2) (3) (6) (7) (8)}.

Belding’s yellowthroat habitat

This species is associated with lowland freshwater habitats, inhabiting oases of reeds, cattails and tules (Schoenoplectus) around marshes, rivers and streams, although it may occasionally also be found in coastal salt marshes ^{(2) (3) (8)}. Although not usually occurring more than 50 metres from water ^(2) (8), Belding’s yellowthroat has occasionally been recorded some distance outside its normal range, and also in drier habitats, suggesting it is capable of dispersing over relatively large distances ^{(2) (6) (7)}.

Belding’s yellowthroat status

Classified as Critically Endangered (CR) on the IUCN Red List ⁽¹⁾.

Belding’s yellowthroat threats

Although recent surveys have found Belding’s yellowthroat to occur at more sites than previously thought, the total area it occupies is still tiny, with suitable areas of habitat very limited and severely fragmented ^(2) (3). The oases inhabited by Belding’s yellowthroat are under great threat from human activities, including burning, reed-cutting, drainage for agriculture and cattle ranching, and over-extraction of water for agriculture and tourist developments ^{(2) (6) (8) (9)}. However, the species has also been found to occur in a newly created marsh in a hotel district and also near active agriculture, suggesting that human activities may sometimes be beneficial ^(2) (6).

Unfortunately, although Belding’s yellowthroat appears to be locally common, it may number no more than a few thousand birds in total, and its population is divided into small, isolated subpopulations, which are more vulnerable to extreme events such as hurricanes, which regularly destroy reedgrass vegetation during the summer ^{(2) (6) (8)}. The remaining area of suitable habitat is thought to total less than ten square kilometres ⁽⁶⁾, and is particularly limited in the southern and central parts of the range, putting subspecies G. b. goldmani at greatest risk ^{(2) (3) (8)}.

Belding’s yellowthroat conservation

The Estero de San José del Cabo Ecological Reserve, a freshwater coastal lagoon in southern Baja California that incorporates Belding’s yellowthroat habitat, was designated as a Ramsar site in 2008 ⁽¹⁰⁾. Conservation work underway at the site includes the development of a Conservation Area Plan, research and monitoring work, educational sign boards and outreach material, and the training of local bird guides ^{(2) (6) (9)}. Other measures recommended for the conservation of this striking species include identifying and surveying further potential sites where it may occur, as well as genetic studies, preventing the burning or cutting of waterside vegetation, the protection of more sites, and the creation of new areas of marsh habitat ^{(2) (6) (7) (8)}. Reintroductions have also been suggested ⁽⁸⁾, and promoting ‘bird tourism’ may be another means by which income can be generated for the protection of key areas of habitat ^(2) (6).

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

Find out more

To find out more about the conservation of Belding’s yellowthroat and other highly endangered bird species, see: 

• BirdLife International:
  http://www.birdlife.org/datazone/species/index.html?action=SpcHTMDetails.asp&sid=9138&m=0
• BirdLife International Preventing Extinctions Programme:
  http://www.birdlife.org/action/campaigns/species_champions/index.html

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Glossary

Subspecies

A population usually restricted to a geographical area that differs from other populations of the same species, but not to the extent of being classified as a separate species.

References

1. IUCN Red List (February, 2010)
   http://www.iucnredlist.org/
2. BirdLife International (February, 2010)
   http://www.birdlife.org/datazone/species/index.html?action=SpcHTMDetails.asp&sid=9138&m=0
3. Dunn, J.L. and Garrett, K.L. (1997) A Field Guide to Warblers of North America. Houghton Mifflin Harcourt, New York.
4. Oberholser, H.C. (1917) A new subspecies of Geothlypis beldingi. The Condor, 19(6): 182-184.
5. Integrated Taxonomic Information System (ITIS) (February, 2010)
   http://www.itis.gov/
6. Hirschfeld, E. (2008) BirdLife International: Rare Birds Yearbook. MagDig Media Limited, Shrewsbury.
7. Erickson, R.A., Hamilton, R.A. and Mlodinow, S.G. (2008) Status review of Belding’s yellowthroat Geothlypis beldingi, and implications for its conservation. Bird Conservation International, 18: 219-228.
8. Rodríguez-Estrella, R., Rubio Delgado, L., Pineda Diez de Bonilla, E. and Blanco, G. (1999) Belding’s yellowthroat: current status, habitat preferences and threats in oases of Baja California, Mexico. Animal Conservation, 2: 77-84.
9. BirdLife International: Species Guardian Action Update: February 2009 - Belding’s Yellowthroat, Geothylpis beldingi (February, 2010)
   http://www.birdlife.org/extinction/pdfs/Beldings_Yellowthroat_Guardian_update_Feb09.pdf
10. The Ramsar Convention on Wetlands (February, 2010)
    http://www.ramsar.org/