Cynanthus latirostris subsp. lawrencei
Creators: name: Silva, Héctor Gómez de
name: Pérez Villafaña, Mónica G.
name: Cruz-Nieto, Javier
name: Cruz-Nieto, Miguel Ángel
Publisher: name: Zenodo
Year: 2020
Subjects: Biodiversity
Taxonomy
Animalia
Chordata
Aves
Apodiformes
Trochilidae
Cynanthus
Cynanthus latirostris
Cynanthus latirostris lawrencei

description: 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 & Collar 2014). Of 11 male specimens of lawrencei at IBUNAM in which it is possible to see the undertailcoverts, typical colours are present in nine specimens but P019534 has a two-toned patern in which the anterior feathers are typical of lawrencei but the largest, posterior feathers are predominantly white with very pale grey central portions, very similar to magicus P001630 from Sinaloa (Fig. 5). Also, the usually whitish undertail-coverts of magicus reach their greyest extreme in P001631 and P020047 (Fig. 6), albeit a pearly grey rather than the brownish grey of lawrencei. We do not believe that any of these specimens are hybrids because no other character suggests this, and their geographic location is too far removed from the Tres Marías (e.g., P020047 is from too far north and inland for lawrencei to be a plausible parent). Species Body part Cynanthus latirostris Wing SexMale Mainland mean Island mean / Cohen’s Tobias / standard error standard error d et al. (n of individuals) (n of individuals) score 52.64 / 0.39 (38) 53.23 / 0.43 (20) 0.27 low 1 Tail Male 31.4 /0.3 (38) 32.64 / 0.35 (19) 0.73 1 Bill length Male 19.58 / 0.13 (37) 18.61 / 0.15 (20) 1.32 1length of tip of rectrix 1WingMaleFemale 3 / 0.1 (34) 1.8 / 0.14 (16) 2.10 low 251.96 / 0.47 (25) 52.37 / 0.22 (22) 0.23 low 1 Tail Female 29.72 / 0.29 (25) 30.28 / 0.21 (22) 0.45 1 Bill length Female 20.48 / 0.22 (24) 19.56 / 0.11 (20) 1.10 1 Amazilia rutila Wing Male 58.74 / 0.29 (46) 70.58 / 0.44 (27) 5.55 3 Tail Male 36.89 / 0.24 (41) 44.54 / 0.36 (26) 4.52 high 2 Bill length Male 21.44 / 0.12 (44) 23.84 / 0.14 (27) 3.15 2 Bill width Male 3.18 / 0.04 (41) 3.63 / 0.08 (22) 1.40 high 1 Wing Female 55.98 / 0.55 (13) 69.04 / 0.46 (18) 6.64 3 Tail Female 35.58 / 0.35 (13) 44.36 / 0.34 (16) 6.69 3 Bill length Female 21.51 / 0.18 (13) 24.63 / 0.17 (15) 4.77 high 2 Bill width Female 3.07 / 0.08 (13) 3.51 / 0.04 (16) 1.89 high 1 Granatellus venustus Wing Male 61.52 / (0.28) / 18 65.85 / 0.28 (21) 3.50 2 Tail Male 69.74 / 0.65 (16) 76.49 / 0.47 (20) 2.86 2 Tarsus Male 19.72 / 0.14 (18) 21.14 / 0.15 (20) 2.24 2 Bill length Male 8.76 / 0.09 (17) 8.96 / 0.04 (19) 0.69 1 width of rectrix 6 male 6.19 / 0.27 (8) 7.22 / 0.17 (9) 1.59 1 white on rectrix 6 male 28.1 / 1.08 (10) 38.38 / 0.71 (14) 3.36 2 rectrix 6 length for same individuals as previous row length of white/ length of rectrix 6 WingmalemaleFemale 69.19 / 0.73 (8) 76.25 / 0.62 (14) 3.21 20.405 / 0.01 (8) 0.51 / 0.01 (14) 3.17 259.48 / 0.33 (11) 63.35 / 0.23 (13) 3.99 2 Tail Female 67.83 / 0.61 (11) 74.28 / 0.37 (17) 3.60 2 Tarsus Female 19.52 / 0.12 (12) 21.24 / 0.08 (14) 4.75 high 2 Bill length Female 8.88 / 0.14 (12) 8.79 / 0.07 (13) 0.23 low 1 white on rectrix 6 female 25 / 0.32 (5) 34.21 / 0.97 (7) 4.89 high 2rectrix 6 length for same individuals as previous row length of white/ length of rectrix 6 femalefemale 66.6 / 1.37 (5) 73.86 / 0.57 (7) 3.01 20.378 / 0.01 (5) 0.463 / 0.01 (7) 3.47 2Species Body part Forpus cyanopygius Wing SexMale Mainland mean Island mean / Cohen’s Tobias / standard error standard error d et al. (n of individuals) (n of individuals) score 88.36 / 0.44 (20) 90.84 / 0.35 (21) 1.38 1 Tail Male 40.81 / 0.39 (20) 42.57 / 0.26 (21) 1.18 1 Tarsus Male 10.86 / 0.05 (20) 11.92 / 0.11 (21) 2.72 2 Bill length Male 13.55 / 0.1 (19) 14.05 / 0.08 (21) 1.24 1 Wing Female 86.98 / 0.37 (31) 90.93 / 0.57 (15) 1.85 high 1 Tail Female 40.9 / 0.33 (31) 43.29 / 0.33 (15) 1.51 1 Tarsus Female 11.06 / 0.08 (31) 12.06 / 0.14 (15) 0.82 1 Bill length Female 13.17 / 0.07 (30) 13.98 / 0.09 (14) 2.24 2 Vireo hypochryseus Wing Male 63.87 / 0.3 (40) 67.83 / 0.33 (30) 2.14 low 2 Tail Male 55.74 / 0.3 (41) 60.45 / 0.23 (24) 2.99 2 Tarsus Male 18.71 / 0.1 (43) 19.98 / 0.09 (28) 2.22 2 Bill length Male 8.8 / 0.08 (42) 9.1 / 0.08 (29) 0.63 1 Coracoid Male 13.74 / 0.09 (12) 12.5 / 0.06 (6) 5.09 low 3 Femur Male 14.75 / 0.08 (14) 14.76 / 0.1 (7) 0.04 0 Wing Female 61.58 / 0.37 (20) 65.93 / 0.23 (23) 3.09 2 Tail Female 53.74 / 0.43 (19) 58.85 / 0.22 (21) 3.40 2 Tarsus Female 18.84 / 0.14 (20) 20.06 / 0.15 (23) 1.81 high 1 Bill length Female 8.7 / 0.09 (20) 9.13 / 0.04 (19) 1.39 1 Coracoid Female 13.47 / 0.04 (9) 12.57 / — (4) — — Femur Female 14.71 / 0.08 (10) 14.96 / 0.06 (5) 1.23 1 Pheugopedius felix Wing Male 56.89 / 0.25 (37) 59.41 / 0.37 (42) 1.26 1 Tail Male 52.49 / 0.29 (31) 56.06 / 0.33 (37) 1.96 1–2 Tarsus Male 21.56 / 0.13 (35) 21.93 / 0.1 (43) 0.52 1 Bill length Male 10.91 / 0.09 (36) 12.4 / 0.12 (41) 2.24 2 Wing Female 53.54 / 0.43 (18) 57.68 / 0.45 (28) 1.95 high 1 Tail Female 49.25 / 0.64 (17) 55.06 / 0.54 (27) 2.13 low 2 Tarsus Female 21.28 / 0.16 (17) 21.37 / 0.12 (29) 0.14 0 Bill length Female 10.54 / 0.14 (18) 12.2 / 0.09 (28) 3.08 2 Melanotis caerulescens Wing Male 114.17 / 0.73 (25) 109.82 / 0.57 (49) 1.14 1 Tail Male 123.47 / 0.92 (28) 109.46 / 0.75 (44) 2.85 2 Tarsus Male 29.18 / 0.18 (29) 28.46 / 0.14 (52) 0.28 low 1 Bill length Male 17.42 / 0.18 (28) 20.06 / 0.15 (46) 2.68 2 Wing Female 110.26 / 0.7 (25) 106.82 / 0.49 (24) 1.15 1 Tail Female 116.38 / 1.07 (25) 104.92 / 0.92 (22) 2.36 2 Tarsus Female 29.3 / 0.18 (31) 28.3 / 0.16 (24) 1.11 1 Bill length Female 17.13 / 0.21 (28) 19.72 / 0.14 (23) 2.82 2 Icterus pustulatus Wing Male 96.22 / 0.3 (66) 104.56 / 0.35 (42) 3.54 2 Tail Male 84.61 / 0.37 (61) 91.52 / 0.32 (39) 2.78 2 Tarsus Male 24.96 / 0.08 (66) 25.17 / 0.17 (28) 0.27 low 1 Species Body partBill lengthSexMale Mainland mean Island mean / Cohen’s Tobias / standard error standard error d et al. (n of individuals) (n of individuals) score 14.78 / 0.78 (66) 17.35 / 0.12 (37) 0.57 1 Bill width Male 5.03 / 0.03 (54) 5.47 / 0.05 (23) 1.91 high 1 Coracoid Male 19.88 / 0.1 (42) 18.87 / 0.13 (9) 1.89 high 1 Femur Male 21.92 / 0.1 (43) 21.83 / 0.34 (9) 0.10 0 Dorsal streaks Male 30.4 / 0.69 (51) 5.4 / 0.75 (30) 5.51 3 Wing Female 90.82 / 0.52 (27) 97.8 / 0.42 (15) 3.13 2 Tail Female 81.33 / 0.68 (19) 85.67 / 0.8 (15) 1.43 1 Tarsus Female 24.81 / 0.13 (27) 25.87 / 0.13 (14) 1.80 high 1 Bill length Female 14.88 / 0.15 (26) 16.68 / 0.2 (13) 2.42 2 Bill width Female 4.98 / 0.04 (24) 5.44 / 0.04 (11) 2.75 2 Coracoid Female 19.28 / 0.11 (25) 18.23 / 0.09 (7) 2.48 2 Femur Female 21.92 / 0.1 (43) 21.83 / 0.34 (9) 0.10 0 Dorsal streaks female 28.2 / 1.35 (17) 4.4 / 1.35 (12) 4.63 2 Leptotila verreauxi Wing Male 143 / 0.63 (32) 152.5 / 0.6 (25) 2.73 2 Tail Male 109.2 / 0.69 (31) 109.5 / 0.57 (25) 0.09 0 Tarsus Male 29.04 / 0.25 (31) 31.58 / 0.24 (25) 1.95 high 1 Bill length Male 9.73 / 0.08 (31) 10.86 / 0.09 (22) 0.24 1 Tail tip length Male 9.8 / 0.25 (27) 8.3 / 0.3 (20) 1.14 1 Wing Female 140.6 / 0.77 (12) 149.8 / 0.54 (21) 3.58 2 Tail Female 108.8 / 1.35 (12) 106.5 / 0.43 (21) 0.64 1 Tarsus Female 27.69 / 0.41 (12) 30.4 / 0.24 (21) 2.13 2 Bill length Female 9.36 / 0.08 (11) 10.97 / 0.12 (18) 3.97 2 Tail tip length Female 9.1 / 0.22 (12) 7.6 / 0.33 (17) 1.36 1 Turdus rufopalliatus Wing Male 123.19 / 0.59 (32) 127.17 / 0.58 (22) 1.31 1 Tail Male 99.29 / 0.69 (32) 102.49 / 0.73 (22) 0.87 1 Tarsus Male 31.48 / 0.21 (32) 34.8 / 0.23 (20) 2.99 2 Bill length Male 13.26 / 0.08 (30) 15.18 / 0.17 (22) 2.98 2 Wing Female 120.42 / 0.5 (20) 124.97 / 0.52 (37) 1.66 1 Tail Female 95.85 / 0.68 (21) 99.6 / 0.52 (39) 1.18 1 Tarsus Female 31.19 / 0.17 (22) 34.67 / 0.21 (34) 3.37 2 Bill length Female 13.8 / 0.14 (20) 15.42 / 0.11 (35) 2.54 2 Setophaga pitiayumi Wing TailTarsusBill lengthWingTail Male (excluding 55.42 / 0.33 (21) 58.28 / 0.34 (42) 1.51 1 mainland insularis) Male (excluding 42.83 / 0.48 (21) 49.14 / 0.33 (37) 3.00 2 mainland insularis) Male (excluding 16.14 / 0.09 (22) 19.11 / 0.08 (40) 6.37 3 mainland insularis) Male (excluding 7.68 / 0.07 (22) 7.76 / 0.06 (40) 0.23 low 1 mainland insularis) Female (excluding 52.22 / 0.33 (12) 56.38 / 0.28 (20) 3.47 2 mainland insularis) Female (excluding 40.34 / 0.37 (11) 48.11 / 0.25 (19) 6.70 3 mainland insularis) Species Body partTarsusBill length Cardinalis cardinalis Wing Sex Mainland mean Island mean / Cohen’s Tobias / standard error standard error d et al. (n of individuals) (n of individuals) score Female (excluding 16.34 / 0.19 (11) 18.84 / 0.14 (20) 5.16 low 3 mainland insularis) Female (excluding 7.78 / 0.1 (10) 7.62 / 0.06 (20) 0.55 1 mainland insularis) Male 91.04 / 0.78 (9) 95.17 / 0.33 (38) 1.88 high 1Tail Male 101.9 / — (4) 96.96 / 0.61 (28) — — Tarsus Male 25.1 / 0.14 (8) 28.06 / 0.12 (44) 5.42 3 Bill length Male 13.22 / 0.29 (8) 14.17 / 0.1 (44) 1.27 1 Bill width Male 8.52 / 0.04 (8) 9.28 / 0.05 (27) 3.79 2 Wing Female 89.93 / 0.64 (6) 91.71 / 0.37 (34) 0.94 1 Tail Female 100.5 / 0.9 (6) 93.29 / 0.46 (21) 3.34 2 Tarsus Female 25.43 / 0.24 (6) 27.37 / 0.19 (32) 0.95 1 Bill length Female 13.47 / 0.32 (6) 13.85 / 0.08 (35) 0.59 1 Bill width Female 8.35 / 0.06 (6) 9.01 / 0.07 (26) 2.42 2 
 Occasional Cynanthus wander between the Tres Marías and the mainland, and apparently sometimes interbreed. A. J. Grayson (in Lawrence 1872: 29) reported seeing one at sea ‘30 miles north’ of the Tres Marías Islands in May 1867, which visited his boat and flew from there toward the islands. Nelson (1899: 46) saw a male latirostris fly past his boat in a straight line toward the islands ‘about midway’ between the Tres Marías and San Blas, Nayarit. An adult male latirostris or lawrencei was observed ‘1 mile east’ of Isla María Magdalena by Grant (1965a: 51) on 25 April 1963 flying towards the later island; and two male lawrencei were collected on the mainland at Sauta, Nayarit, by C. Lamb (MLZ 28073 on 5 May 1940, and MLZ 41912 on 23 April 1946, with two male magicus collected there around the same date as the 1940 specimen; J. Maley pers. comm.). MLZ 28073 has the only remaining undertail-covert feather typical of lawrencii while, contra Grant (1965a), MLZ 41912 has the anterior feathers grey-brown and the posterior undertail-coverts very pale whitish grey (like the IBUNAM material in Fig. 5; MLZ specimen photos, courtesy of J. Maley). 
 Among mainland specimens at IBUNAM, one male (P001633 from just north-west of Las Varas, Nayarit, along the Zacualpan road) appears to be a hybrid. It has a lawrencei - like shorter bill and undertail-coverts colour, but a magicus -like blue throat (Fig. 7). This is consistent with the observation that hybrids between hummingbirds of the ‘emerald’ group (sensu McGuire et al. 2014) do not show mixed colours but rather a combination of characteristics of the parental species (Graves 2003a,b). 
 A male Broad-billed Hummingbird we photographed on Isla María Cleofas on 26 April 2016 appears to combine the plumage characters of magicus and lawrencei, namely the deep blue throat and blue-green breast / belly of the former with the undertail-coverts of the later (Fig. 8), thus apparently representing another hybrid. 
Del Hoyo & Collar (2014) used the English name Tres Marías Hummingbird, but we prefer to avoid potential confusion given that there are two species of hummingbird on the islands; consequently, we prefer the name Lawrence’s Hummingbird.
description: Published as part of 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?, pp. 7-37 in Bulletin of the British Ornithologists' Club 140 (1) on pages 11-19, DOI: 10.25226/bboc.v140i1.2020.a3, http://zenodo.org/record/13755707