Cynanthus latirostris lawrencei (von Berlepsch, 1887)

Silva, Héctor Gómez de, Pérez Villafaña, Mónica G., Cruz-Nieto, Javier & Cruz-Nieto, Miguel Ángel, 2020, Are some of the birds endemic to the Tres Marías Islands (Mexico) species?, Bulletin of the British Ornithologists’ Club 140 (1), pp. 7-37 : 11-12

BROAD-BILLED HUMMINGBIRD Cynanthus latirostris lawrencei (vs. C. l. magicus total score 8).

Scored 9 by del Hoyo & Collar (2014) based on colours of throat (‘glitering turquoise-green’ vs. ‘sapphire-blue’), breast (‘greeny-bronze’ vs. ‘turquoise-blue’) and undertail-coverts (‘whitish-edged darkish-grey’ vs. ‘pale grey-white’), and slightly shorter bill (most of these characters are visible in Figs. 2–4). However, the throat and breast characters, which del Hoyo & Collar (2014) scored separately, could be viewed as a single character (less blue on iridescence of throat and breast), and we could not clearly discern the difference in breast colour in IBUNAM specimens. Therefore we ignore the breast colour character (thereby ‘losing’ two points), but this enables a further colour character to be scored. Grant (1965a, based on 23 male and 22 female lawrencei vs. 41 male and 25 female magicus) mentioned additional colour differences, including darker grey underparts in females (score 1), and that 75% of his lawrencei samples of both sexes had darker green upperparts compared to 75% of his magicus samples (not scored). Grant (1965a) also mentioned an additional morphometric difference (slightly but significantly smaller grey tips to the rectrices, at least in females; not scored). According to Grant’s (1965a) data, shorter bill length in lawrencei scores only 1, not 2 as in del Hoyo & Collar (2014), but wings and tail are longer (score 1).

We found that the undertail-coverts character does not distinguish 100% of one taxon from 100% of the other, as implied in the literature ( Ridgway 1911, Grant 1965a, del Hoyo &

Species Body part

Cynanthus latirostris Wing