Justification of Red List Category
This species is known only from a few specimen and sight records, and there is no information on the true extent of its distribution, population size or trends. The challenges inherent in identification of neotropical swifts mean that even sight records by experienced observers should be treated with caution. Until further information is available on the species' status, it is classified as Data Deficient.
Partners in Flight estimated the population to number fewer than 50,000 individuals (A. Panjabi in litt. 2008), thus it is placed in the band 20,000-49,999 individuals here.
The population trend is difficult to determine because of uncertainty over the species's ecological requirements.
Cypseloides storeri has a restricted range in south-west Mexico, where it is known only from a few sight records and six specimens taken in Guerrero (Sierra de Atoyac), Michoacán (Tacámbaro) and Jalisco (Sierra de Manantlán and Juanacatlán) (Navarro et al. 1992, Navarro et al. 1993, Ibánez-Hernández et al. 2003). The most recent published observations are of a single individual believed to be this species in a mixed flock of c.100 swifts near Tacámbaro in September 1995 (Howell et al. 1997), a record of several birds showing features of C. storeri within a flock of C. rutilus near Manzanillo, Colima in February 2002 (Tobias et al. 2006, D. Lane in litt. 2006) and another possible single at Teotitlan del Valle, Oaxaca in March 2010 (Howell 2011). Unpublished records include one about 5km south of Tacámbaro in July 2009 (M. Patten per J. King in litt. 2010, 2011), at least 2-3 at an apparent colony at Tacámbaro on 17-18 June 2010 (J. King in litt. 2010, 2011), several photographed at Rancho Primavera, El Tuito, Jalisco in 24 January 2012 (B. Gibbons per J. King in litt. 2012), and potentially some photographed and voice recorded at Tacámbaro (S. Howell in litt. 2016).
It has been collected at 1,500-2,500 m in montane forest and transition pine-oak / dry tropical deciduous forest in areas with numerous waterfalls and ravines (del Hoyo et al. 1999). The Tacámbaro sighting involved a mixed flock of swifts flying over hills and fields bisected by a narrow, steep-sided canyon. Well documented records are from February, June, July and September, indicating that the species may be sedentary (Tobias et al. 2006). The specimen taken in June had enlarged testes indicative of breeding (Ibánez-Hernández et al. 2003).
Conservation Actions UnderwayNo targeted actions are known but this species is on the watch list as part of the State of North America's Birds (North American Bird Conservation Initiative 2016).
Conservation Actions Proposed
Carry out surveys in potentially suitable habitat near historical sites and elsewhere in south-west Mexico. Clarify its ecological requirements and migratory status.
Text account compilers
Benstead, P., Capper, D., Isherwood, I., Sharpe, C J, Symes, A., Westrip, J.
Patten , M., Howell, S., Gibbons, B., Lane, D., King, J.
BirdLife International (2019) Species factsheet: Cypseloides storeri. Downloaded from http://www.birdlife.org on 18/06/2019. Recommended citation for factsheets for more than one species: BirdLife International (2019) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 18/06/2019.