• Summary
• Text account
• Data table and detailed info
• Distribution map
• Reference and further resources

Justification of Red List category
This species is found in just five wetlands and occurs throughout a limited range. Habitat within the range is being degraded, primarily as a result of continuing drainage and water extraction from suitable marsh habitats. The species therefore qualifies as Vulnerable.

Population justification
The population is estimated to number 2,500-9,999 individuals based on an assessment of known records, descriptions of abundance and range size. This is consistent with recorded population density estimates for congeners or close relatives with a similar body size, and the fact that only a proportion of the estimated Extent of Occurrence is likely to be occupied. This estimate is equivalent to 1,667-6,666 mature individuals, rounded here to 1,500-7,000 mature individuals.

Trend justification
There are no data on population trends; however, the species is suspected to be declining rapidly owing to wetland drainage.

Geothlypis speciosa is currently known from only five wetlands, all in the states of Guanajuato, Michoacán and México, central Mexico. None of these areas have been censused since the 1980s (Stattersfield et al. 1998), when it was quite abundant at Lago Cuitzeo, Michoacán, and still common on the upper río Lerma around Lerma da Villada, San Mateo Atenco and San Pedro Techuchuco, México (an area where it was historically abundant). There are further small populations at Lago Yuriria, Guanajuato, and Lago Pátzcuaro, Michoacán. The Cuitzeo, Yuriria, and Pátzcuaro populations are thought to constitute subspecies limnatis whereas the easternmost population, at Ciénegas del Lerma, is thought to comprise subspecies speciosa (Pérez‐Arteaga et al. 2018). It has been extirpated from Lago Texcoco, México, and there have been no records from Lago Zumpango, México, or Presa Solis, Guanajuato, since 1966. It is however, recently reported from Lake Zirahuén, a previously unreported location (Pérez‐Arteaga et al. 2018). The available habitat for this species is now estimated at just 94.95 km², 59.5% of which is found at Lake Cuitzeo with less than 1% found at Lake Zirahuén (Pérez‐Arteaga et al. 2018). 

It is restricted to lakeshore and river marshes comprising cattails and hard-stemmed bulrushes. It appears to require extensive reedbeds and is not found in degraded habitats like many other Geothlypis species (S. N. G. Howell in litt. 1998). The nesting period is probably March-June.

G. speciosa does not tolerate habitat modification (S. N. G. Howell in litt. 1998), and thus the most severe threat is the loss of its wetland habitats. The marshes within its range have been greatly reduced in size, having been drained and planted with crops. The marshes in the upper río Lerma are fragmented as a result of drainage and water extraction to supply México City and Toluca. The water-levels of Lagos Yuriria, Pátzcuaro and Cuitzeo are falling through drainage and a natural build-up of organic material.

Conservation Actions Underway
None are known.

Conservation Actions Proposed
Establish protection and ensure restoration of marsh habitat at all wetlands where the species remains. Implement controls on the burning and illegal harvesting of aquatic plants. Census populations at the five remaining sites and assess the degree of isolation amongst the remaining populations. Establish the species's presence at Ciénega de Tláhuac and survey any suitable habitat near Lago Zumpango. Assess the viability of reintroductions to man-made and restored wetlands within its historical range. Determine the basic ecological requirements, degree of inbreeding and nesting requirements for extant populations (Pérez‐Arteaga et al. 2018).

13 cm. Yellow-olive, masked bird. Male has brownish-olive upperparts and black mask, sometimes with greyish wash on sides of crown and nape. Deep yellow underparts, washed orange on chest and ochraceous on flanks. Female lacks mask and has olive face with pale eye-ring and pale buff supercilium. Immature male resembles male with black on face restricted to lores and ear-coverts. Juvenile has brownish-olive head and upperparts, and paler olive-yellow underparts. Dark brown legs. Black bill. Similar spp. Common Yellowthroat G. trichas has pale legs, lighter appearance, less rich underparts and lacks ochraceous wash on flanks. Male has less extensive black forecrown and lacks greyish wash around mask. Voice Harsh nasal chreh call. Song a rapid series of chip notes.

Text account compilers
Hermes, C., Everest, J.

Contributors
Capper, D., Howell, S., Isherwood, I., Mahood, S., Pople, R. & Sharpe, C.J.

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Recommended citation
BirdLife International (2024) Species factsheet: Black-polled Yellowthroat Geothlypis speciosa. Downloaded from https://datazone.birdlife.org/species/factsheet/black-polled-yellowthroat-geothlypis-speciosa on 23/12/2024.
Recommended citation for factsheets for more than one species: BirdLife International (2024) IUCN Red List for birds. Downloaded from https://datazone.birdlife.org/species/search on 23/12/2024.