SPECIES

Chihuahuan Meadowlark Sturnella lilianae Scientific name definitions

Johanna K. Beam, Levi A. Jaster, William E. Jensen, and Wesley E. Lanyon
Version: 1.0 — Published October 25, 2022

Systematics

Systematics History

The Eastern Meadowlark (Sturnella magna) subspecies S. m. lilianae was first described by Oberholser in 1930 based on donated study skins to the Cleveland Museum of Natural History (13). Previously, this population of birds was thought to be part of S. m. hoopesi based on plumage similarity, but the donation of specimens led to a closer look at birds from Arizona and New Mexico, and it was determined that these birds were a distinct subspecies based on longer wings, shorter tail, tarsus, and bill, and a more saffron-colored breast. The subspecies S. m. auropectoralis was described four years later in 1934, and was thought to be allied with S. m. lilianae due to similar characteristics of extensive white in the tail, the saffron-colored breast, and short tarsus and tail (14). The distinctiveness of these two subspecies became more well known when both Rohwer and Lanyon started publishing their research on the morphology, song, and habitat differences these two subspecies had from other Eastern Meadowlark populations. The first to study the genetic distinctiveness of meadowlarks was Barker et al. in 2008 (15). They found that this subspecies, along with auropectoralis, should not be considered a subspecies any longer and be promoted to species status. Sibley and Monroe's World Checklist of Birds classified "Lilian's Meadowlark" as its own species in 1993 (16). However, a proposal in favor of the split of lilianae and auropectoralis from Eastern Meadowlark submitted to the American Ornithological Society's North American Classification Committee (NACC) in 2016 did not pass (17). It was not until Beam et al.'s 2021 paper (18) on meadowlarks and subsequent proposal to the NACC that the split of lilianae and auropectoralis from Sturnella magna was passed (19, 20).

Geographic Variation

Little variation geographically, although birds in central Mexico (S. lilianae auropectoralis) are smaller with slightly shorter wings and slightly darker mantle (14, 21).

Subspecies

Two subspecies recognized. Note that however previous research has suggested that the subspecies Sturnella magna saundersi was part of the Sturnella lilianae group, it is not included in the split of Eastern Meadowlark and Chihuahuan Meadowlark and remains a subspecies under Eastern Meadowlark. S. m. saundersi was established based on plumage and measurements of bird specimens collected in the non-breeding season and may not represent a valid subspecies (22, 18). Until its validity can be shown, it will remain under Eastern Meadowlark.


SUBSPECIES

Sturnella lilianae lilianae Scientific name definitions

Systematics History

Sturnella magna lilianae Oberholser, 1930, Scientific Publications of the Cleveland Museum of Natural History p.103 pl.18.—Huachuca Mountains, Arizona (13).

Distribution

Largely resident in desert grassland of southeast and central Arizona east to southern New Mexico and west Texas south at least to northeastern Sonora and northern Chihuahua. May also reach extreme southeast Colorado (23). Winters north to central Arizona and has reached lower Colorado River at that season (24). Disjunct from Eastern Meadowlark, possibly by the Llano Estacado in west Texas(25).

Identification Summary

Similar in size to both Eastern Meadowlark and Western Meadowlark, tail more extensively white than any other species. Separable from Western Meadowlark by rectrix 3 essentially white, not brown, and pale, not dark, auricular (26). For full description see Plumages.


SUBSPECIES

Sturnella lilianae auropectoralis Scientific name definitions

Systematics History

Sturnella magna auropectoralis Saunders, 1934, Auk p.42.—Tuxpan, Jalisco, Mexico (14).

Distribution

Resident in west Mexico from southern Sinaloa, coastal Nayarit, and southern Durango across the Trans-Volcanic Belt east to the upper Río Lerma, Estado de México. Birds between Estado de México and the Sierra Madre Oriental, in Tlaxcala and Puebla and adjacent areas, may represent auropectoralis (27), but more study is needed.

Identification Summary

Large (ca. size of S. l. lilianae, but wings average shorter). plumage like S. l. lilianae but breast with a distinct orange wash.

Related Species

Phylogenetic Relationships

Formerly considered conspecific with the Eastern Meadowlark until 2022. A recent study by Beam et al. (18) found that Chihuahuan Meadowlark was sister to the clade of both Eastern Meadowlark and Western Meadowlark, and genetically and acoustically divergent from either species. The use of whole-genome data was in contrast to that of Barker et al. (15), which used mitochondrial genes (CYTB and ND2) and a sex-linked intron (ACO1-I9), but both studies largely found the same results: Sturnella lilianae is not a subspecies of Sturnella magna due to genomic differences. Additionally, Chihuahuan Meadowlark split off prior to the Eastern Meadowlark and Western Meadowlark split, suggesting it is an older lineage than either Eastern or Western.

Within the Icteridae, meadowlarks and their allies form a distinct lineage, with the tropical and south temperate red-breasted species (genus Leistes, which were formerly considered Sturnella) sister to the clade containing Chihuahuan Meadowlark, Eastern Meadowlark, and Western Meadowlark (28, 29). Molecular phylogenies supported Eastern Meadowlark as sister to Chihuahuan Meadowlark, with both in turn sister to Western Meadowlark (15, 29) but analysis of these relationships with more genomic data support Eastern Meadowlark and Western Meadowlark as sister species, with Chihuahuan Meadowlark sister to that group (18).

Hybridization with Other Species

No studies have been performed on hybridization between Chihuahuan Meadowlark and either Eastern Meadowlark or Western Meadowlark. Based on the absence of introgression in the genomes of all meadowlark species, hybridization is likely to be extremely rare and/or hybrids are infertile, leaving no signature in the populations (18). A study by Rohwer based on specimen measurements of Chihuahuan Meadowlark and Western Meadowlark suggests phenotypically intermediate individuals between the two species may occur rarely (30).

Nomenclature

Formerly known as "Lilian's" Eastern Meadowlark or simply Lilian's Meadowlark.

Fossil History

No known fossils of Chihuahuan Meadowlark.

Recommended Citation

Beam, J. K., L. A. Jaster, W. E. Jensen, and W. E. Lanyon (2022). Chihuahuan Meadowlark (Sturnella lilianae), version 1.0. In Birds of the World (N. D. Sly, Editor). Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/bow.lilmea2.01