Data Zone
Justification of Red List category
This species is classified as Endangered owing to its extremely small range within which it has a very small number of locations and is subject to continuing declines in the size of its range, habitat quality and population size.
Population justification
In 1997 it was estimated that 5,380-6,150 adults were occupying the key site for this species. There were reportedly a small number of individuals at other locations. Densities of 2.9 territories/ha have been recorded at La Cima (Oliveras de Ita et al. 2001), and later surveys have suggested a density of 2 individuals/ha (V. Rodríguez and H. Berlanga in litt. 2016). This later estimate would imply a population of c. 2,000 individuals, roughly equivalent to 1,300 mature individuals. Therefore, using the maximum and minimum estimates provided for this species this site may hold 1,300-6,150 mature individuals. Given the uncertainty over populations elsewhere, the population size is put into the range 1,300-9,999 mature individuals.
Trend justification
Global population trends have not been accurately estimated but the area of suitable habitat at the principal site for the species, where over 90% of the global population occurs, has declined by c. 50% in the last 10 years. In addition the species has disappeared from three out of four historic localities in the north of its range (Oliveras de Ita and Gómez de Silva 2007). Overall, the species is feared to be declining rapidly. It is in danger of being extirpated from further portions of its range (Aguirre et al. 2012).
This species was known from disjunct areas in north Jalisco, south Durango, and around the Distrito Federal-Morelos border, Mexico, but is now confined to the latter two areas, over 800 km apart. A recent survey concluded that the species was confined to two localities: Ejido Ojo de Agua-El Cazador, southern Durango, and the fragmented grasslands of "sur del Valle de México" centered around La Cima and Milpa Alta, Distrito Federal (Oliveras de Ita and Gomez de Silva 2007, M. A. Cruz-Nieto in litt. 2008). The species was subsequently recorded at a further locality known as 'El Bajío la Cantera' in San Dimas municipality, Durango, around 65 km from the closest known locality (Martínez-Guerrero et al. 2018).
The southern population has been recorded from around El Capulín-La Cima and Santa Ana Tlacotenco, with fewer records from north-east of Volcán Yecahuazac, east and north of Volcáns San Bartolito and Comalera, north of Volcán Tuxtepec, west of Volcán Tulmiac, north of Acopiaxco (Cabrera 1999, Cabrera and Escamilla 2000) and north-east of Coexapa (H. Gómez de Silva in litt. 1999, Oliveras de Ita et al. 2001, Oliveras de Ita and Gómez de Silva 2002). A record at Los Dinamos, Distrito Federal in 1993 (Wege and Long 1995) refers to a misidentified juvenile Song Sparrow Melospiza melodia (H. Gómez de Silva in litt. 1999). The species went unrecorded in Durango from 1951 until it was rediscovered there in 2004 (J. M. Lammertink in litt. 2009). The northern population is now thought to be restricted to two localities, having disappeared from three historical sites (Oliveras de Ita and Rojas-Soto 2006).
The population at Ejido Ojo de Agua-El Cazador comprises at least three breeding pairs concentrated in an area of 0.5 ha within an 80 ha marsh, whilst around La Cima and Milpa Alta there are perhaps 5,380-6,150 adults equating to 2,300 breeding pairs (Oliveras de Ita and Gomez de Silva 2007, M. A. Cruz-Nieto in litt. 2008), although later surveys in 2012-2015 have estimated the population density at only 2 individuals/ha equating to roughly 2000 individuals (V. Rodríguez and H. Berlanga in litt. 2016). Twenty-eight singing males were recorded at the 55 ha 'El Bajío la Cantera', Durango in 2016 (Martinez-Guerrero et al. 2018).
It inhabits medium to tall bunch-grass meadows (zacatón) mostly at elevations of 2,800-3,050 m, but populations in Durango were as low as 2,285 m. Specifically, its preferred habitat is primary tall fodder grass areas dominated by Muhlenbergia macroura, M. affinis, Festuca amplissima and Stipa ichu which are subject to agriculture and cattle activities. It feeds in agricultural fields and birds have been seen singing from the tops of zacatón clumps in a heavily grazed and poorly drained field. It lays a brood of 2 to 4 eggs. Nesting success is c.36% at La Cima, with nests constructed low down in bunch-grass tussocks (Oliveras de Ita et al. 2001).
There is widespread anthropogenic burning of habitat, mostly to promote new growth of grazing pasture for sheep and cattle (Oliveras de Ita et al. 2001, Martínez-Guerrero et al. 2018). There is also conversion to agriculture (mainly oats), bunch-grass is sometimes cut for thatch and brushes and a degree of urban encroachment is occurring. Most remaining habitat is close to volcanic rock outcrops or on slopes where it is difficult to operate a tractor (Oliveras de Ita et al. 2001). However, rock extraction at La Cima suggests that many of these areas are likely to be converted to agriculture (Oliveras de Ita et al. 2001). La Cima has been planted with pines and, if these survive, the sparrow will be extirpated from this site (M. Grosselet in litt. 2011). Autopsies on two individuals showed that organ systems had collapsed as a result of mycotoxins from contaminated grain (Oliveras de Ita et al. 2001). There is a high level of nest failure owing to heavy predation which may be exacerbated by habitat fragmentation (P. Escalante in litt. 2006). Loss of water sources owing to extraction for livestock and human uses poses an additional threat (Aguirre et al. 2012).
Conservation and Research Actions Underway
Surveys have found new localities, identified the important areas for protection, investigated the breeding ecology and censused the population at La Cima (Cabrera 1999, Cabrera and Escamilla 2000, Oliveras de Ita et al. 2001). CONABIO, UNAM and CORENA have been working on a community-based species conservation project since 2008 with the support of Cornell Laboratory of Ornithology. The project is focused on preserving and restoring habitat with the involvement of landowners and managers. In 2011 members of the community were trained for bird monitoring in order to participate in 2012 in an effort conducted by CONABIO to assess the current population status of the species (H. Berlanga et al. in litt. 2012).
Conservation and Research Actions Proposed
Monitor remaining populations (L. Cabrera in litt. 2000). Survey suitable habitat in Durango. Integrate local people in developing appropriate grassland management strategies, including fire management (L. Cabrera in litt. 2000). Ensure that grain storage prevents potential infection by micotoxins (Oliveras de Ita et al. 2001). Protect remaining habitat fragments.
12 cm. Rufous, grey-and-white sparrow. Rufous upperparts (scaled buff when fresh) streaked black. Dark brown wings and tail edged rufous. Greyer on nape. Grey streaking on central crown. Blackish-brown lateral crown-stripes. Grey supercilium and ear-coverts. Blackish eye-stripe, moustache and malar stripes. Whitish underparts (washed buff when fresh), heavily streaked black. Grey bill. Pinkish legs. Juvenile duller with greyish-buff supercilium and yellowish bill. Similar spp. Song Sparrow Melospiza melodia is larger and less rufous, with a longer round-tipped tail (notched in Xenospiza), and lacks the bright yellow wing bend of this species. Voice Song a varied series (7-12, occasionally as few as four) of chip notes with buzzes. Nasal nyew or thin sii call, very similar to Song Sparrow.
Text account compilers
Hermes, C., Wheatley, H., Fernando, E.
Contributors
Ashpole, J, Berlanga, H., Bird, J., Butchart, S., Cabrera, L., Capper, D., Cruz-Nieto, M.Á., Escalante, P., Grosselet, M., Gómez de Silva, H., Lammertink, M., Mahood, S., Pople, R., Rodríguez, V., Sharpe, C.J. & Westrip, J.R.S.
Recommended citation
BirdLife International (2024) Species factsheet: Sierra Madre Sparrow Xenospiza baileyi. Downloaded from
https://datazone.birdlife.org/species/factsheet/sierra-madre-sparrow-xenospiza-baileyi 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.