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

Justification of Red List category

This species has a very large range, and hence does not approach the thresholds for Vulnerable under the range size criterion (Extent of Occurrence <20,000 km² combined with a declining or fluctuating range size, habitat extent/quality, or population size and a small number of locations or severe fragmentation). The population trend appears to be stable, and hence the species does not approach the thresholds for Vulnerable under the population trend criterion (>30% decline over ten years or three generations). The population size may be moderately small to large, but it is not believed to approach the thresholds for Vulnerable under the population size criterion (<10,000 mature individuals with a continuing decline estimated to be >10% in ten years or three generations, or with a specified population structure). For these reasons the species is evaluated as Least Concern.

Population justification
The global population is estimated to number 25,000 mature individuals (Partners in Flight 2019).

Trend justification
A remote sensing study found that habitat loss within the range has been negligible (< 1% over three generations; Tracewski et al. 2016). Therefore, in the absence of evidence for any declines or substantial threats, the species is assessed as being stable.

Leiothlypis crissalis is a fairly common but local breeder, occurring from Coahuila to north-east Zacatecas and northern San Luis Potosí, Mexico, and extreme south-west Texas, U.S.A. (Curson et al. 1994, Howell and Webb 1995). It winters in west Mexico from south Sinaloa, south to Guerrero and Morelos (Howell and Webb 1995).

The species breeds in pine-oak, oak and pinyon-juniper woodland, between 1,500 and 3,000 m (Curson et al. 1994, Howell and Webb 1995), and is most common in pine-oak woodland with a ground cover of bunchgrass (Wauer 1994). It winters in brushy understorey of humid to semi-humid montane forest from 1,500 to 3,500 m (Howell and Webb 1995). The nest is usually on the ground, and eggs have been found in May (Curson et al. 1994).

Grazing by goats, sheep and other exotic herbivores, increases in the populations of feral cats and dogs, and nest parasitism by Brown-headed Cowbirds Molothrus ater are potentially severe threats to populations of this warbler in Mexico (Wauer 1994).

Conservation Actions Underway
None are known.

Conservation Actions Proposed
Regularly monitor the population at selected sites across its range to determine trends. Research the effects of grazing and wood cutting on populations of the species. Examine the effects of Brown-headed Cowbird parasitism at the population level. Protect significant areas of forest, in both strictly protected areas and community led multiple use areas.

Text account compilers
Hermes, C.

Contributors
Isherwood, I., Mahood, S., O'Brien, A., Palmer-Newton, A. & Symes, A.

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Recommended citation
BirdLife International (2024) Species factsheet: Colima Warbler Leiothlypis crissalis. Downloaded from https://datazone.birdlife.org/species/factsheet/colima-warbler-leiothlypis-crissalis 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.