Berylline Hummingbird, Saucerottia beryllina
Berylline Hummingbird, Saucerottia beryllina viola. Photograph taken within a residential community in Alamos, Sonora, November 2019. Photograph and identification courtesy of David F Smith, Alamos, Sonora.
Berylline Hummingbird, Saucerottia beryllina viola. Photograph taken within a residential community in Alamos, Sonora, December 2017. Photograph and identification courtesy of David F Smith, Alamos, Sonora.
Background and Identification
The Berylline Hummingbird, Saucerottia beryllina viola, is one of five subspecies of Berylline Hummingbird, four of which are found in Mexico. They are a member of the Trochilidae Family of Hummingbirds, which has three hundred fifty-two members in one hundred thirteen genera, and one of ten global species of the Saucerottia Genus. Known for their striking iridescent plumage, they shimmer in the sunlight and are a delight for birdwatchers to spot. Berylline Hummingbirds are agile fliers, capable of hovering in place as they feed on nectar from flowers. They occasionally eat small insects to supplement protein in their diet. They are known in Mexico as Amazilia Berilina.
The Berylline Hummingbird is mid-sized in stature. Both sexes are 8 cm (3.1 inches) to 10 cm (3.9 inches) in length. Females average 4.0 g (0.14 oz) in weight, and males average 4.4 g (0.16 oz). The sexes are similar in appearance, but females have paler markings on the throat the belly is a deeper gray and their bill lacks the pinkish base. Both sexes have a bronze-green to coppery head, a green and blue back, a rump with grayish tinges, and a cinnamon-colored belly. The base of their primaries and secondaries are chestnut; their underparts are glittering golden green, and the upper tail coverts and rectrices are dark violet-blue. Their bill is straight, medium-sized, and black except for the pinkish basal half of the mandible. Juveniles are less iridescent and bright than mature adults and resemble females until they are about 1 year of age. In Arizona, a hybrid species between Berylline Hummingbirds and Rivoli’s Hummingbirds, Eugenes fulgens, takes an intermediate appearance. These specimens are larger and longer-billed than Saucerottia. Beryllina and have less rufous in their wings and a golden-toned rump and tail.
Habitat and Geographical Range
The Berylline Hummingbird is most commonly found in mountain foothills that contain oak and pine forests. They also inhabit forest edges, scrub, clearings with trees, thorn forests, and suburban gardens. They are found at elevations up to 3,000 m (10,000 feet) and are most common at altitudes between 500 m (1,640 feet) and 1,800 m (5,900 feet). Their legs cannot support their body weight, so their only mode of locomotion is flight. The Berylline hummingbirds are poorly studied and very little about their behavioral patterns has been documented.
The viola subspecies of Berylline Hummingbirds is found in Western Mexico along the Pacific Slope from Sonora to Michoacán and Guerrero. The four other subspecies are found in Southern Mexico and Central America. The northern populations migrate to warm locations for the winter; the southern populations are non-migratory and year-round residents. However, they are known to make local altitudinal migrations to lower elevations after breeding to follow seasonal blooms of trees and shrubs. Populations in the southwest United States are altitudinal migrants, often moving to higher elevations during the breeding season and descending to lower elevations in the non-breeding seasons.
Common Misidentifications
The Berylline Hummingbird can be mistaken for other hummingbird species with similar coloration, particularly the Buff-bellied Hummingbird, Amazilia yucatanensis, and the Broad-billed Hummingbird, Cynathus latirostris. The Buff-bellied Hummingbird, while also green, has a more buffy or rufous-colored belly and lacks the bronze-green back of the Berylline. The Broad-billed Hummingbird, on the other hand, has a more distinctly blue throat and a brighter, more conspicuous blue tail. Careful observation of the Berylline’s combination of green and bronze plumage, as well as its more specific habitat preferences, can aid in accurate identification.
Conservation Status
From a conservation perspective, the Berylline Hummingbird is currently considered to be of Least Concern with stable, widely distributed populations.