Plain-capped Starthroat

The Plain-capped Starthroat, known scientifically as Heliomaster constantii, is a hummingbird of modest elegance. This avian jewel measures between 11 to 13 cm in length, with males tipping the scales at approximately 7.4 g and females slightly lighter at around 7.2 g. Both sexes boast a long, almost straight black bill and a distinctive white streak post the eye, with plumage that is remarkably similar between the genders.

Identification Tips

Adults of the species are adorned with metallic bronze-green upperparts, and a conspicuous white streak graces the rump. The crown presents a less metallic sheen compared to the body. The face is tinged with dusky hues, complemented by a broad white "moustache". The chin ranges from sooty to blackish, while the gorget shimmers with shades of metallic red to purplish red. The underparts are a muted brownish gray, transitioning to a white belly, and the undertail coverts are pale gray with generous white tips. A tuft of white feathers can be found on the flanks. The tail feathers are a mix of bronze green with dusky ends, and blackish with white edges on the inner margins. Immature birds display a dark sooty brown throat with grayish white feather margins.

Habitat

The Plain-capped Starthroat inhabits a diverse array of arid to semi-arid landscapes, including mature forest interiors and edges, thorn forests, scrublands, gallery forests, secondary forests, and open areas dotted with trees.

Distribution

The species is found from Mexico to Costa Rica, with three subspecies delineating its range. The northernmost H. c. pinicola resides from Sonora to Jalisco in Mexico, while H. c. leocadiae is found in southwestern Mexico and western Guatemala. The nominate subspecies, H. c. constantii, spreads from El Salvador through Honduras and Nicaragua into northwestern Costa Rica. Notably, H. c. pinicola has also been recorded in Arizona.

Behaviour

The Plain-capped Starthroat is generally a year-round resident within its range, though in Sonora it is primarily present during the breeding season, with a few winter records. In Arizona, sightings are predominantly between May and October.

Feeding

This species indulges in nectar from a plethora of flowering plants, employing a trap-lining foraging strategy but occasionally males will defend patches of flowers. It forages at various heights, from the understory to the canopy. In addition to nectar, it also consumes small insects, which it captures in flight or gleans from vegetation.

Breeding

Breeding phenology of the Plain-capped Starthroat is not well-documented across its entire range. In western Mexico, breeding occurs from January to June, and in Costa Rica, it takes place from October to January. The bird constructs a shallow cup nest from plant down, adorned with lichen on the exterior, typically situated near the tip of a high tree branch.

Song & Calls

The vocal repertoire of the Plain-capped Starthroat includes a series of sharp chips interspersed with varied tones, forming a melodic sequence. Calls range from a high-pitched, melodious slurred "tseep" or "cheek" to a sharp "peek", and during chases, a high-pitched, piercing twitter can be heard.

Conservation Status

The IUCN has classified the Plain-capped Starthroat as Least Concern. It boasts a vast range and an estimated population of 50,000 to 500,000 mature individuals. Although the population appears to be in decline, no immediate threats have been identified. The species' abundance varies from uncommon to common across different locales, and human activity seems to have minimal short-term impact on its well-being.