Plain-capped Starthroat Hummingbird Species

The Plain-Capped Starthroat (Heliomaster constantii) is a small hummingbird found in central and western Mexico. With its metallic green body, white breast, and distinct plain orange cap on the head, this species is unmistakable among North American hummingbirds.

Range and Habitat
The plain-capped starthroat is found in the highlands of west-central and western Mexico. Its range extends from southern Sonora south through western Jalisco and Colima to Guerrero. It inhabits mountain foothill scrub, second growth, forest edges, and semi-open areas from around 1500 to 8000 feet in elevation.

The plain-capped starthroat is one of the larger hummingbird species, reaching 3.5 to 4 inches in length. As its name suggests, it can be identified by its conspicuous plain orange cap on the head. The rest of the head and throat are an iridescent emerald green. The back and upper breast are also metallic green in color. The lower breast and belly are white. The long thin bill is black, adapted for probing flowers. The tail is blackish with white tips on the outer tail feathers. The males and females look similar.

Food and Feeding
Like all hummingbirds, the plain-capped starthroat feeds on flower nectar and tiny insects. It uses its specialized long bill to drink nectar while hovering at flowers. Some favorite nectar sources are plants in the bignonias, lantanas, salvias, and hummingbird bushes. The starthroat also hawks small insects in flight, capturing them with its bill.

The plain-capped starthroat lives alone or in pairs, not in large flocks. Males perform elaborate aerial courtship displays to attract females, flying in loops and dives. Their call is a sharp chip note. These hummingbirds can be aggressive in defending their feeding territories from intruders. They perch more often than many other hummingbird species.

Males establish breeding territories to attract mating females in the spring. Females build a small cup-shaped nest out of plant fibers and spider webs, attached to a branch. They lay two tiny white eggs. Incubation lasts 14-16 days and the chicks fledge in about 20-26 days. The female cares for the young though the male may participate in feeding after they hatch.

This species is generally non-migratory. Some northern populations may migrate short distances seasonally but most are resident year-round in their breeding range in Mexico. They do make seasonal elevational movements, increasing the time spent at higher elevations in the summer breeding season.

Conservation Status
With a relatively widespread range and no major threats, the plain-capped starthroat is considered a species of Least Concern by the IUCN Red List. Habitat loss is a potential concern, though it remains common through much of its range. Providing nectar flowers and insect-rich habitat can help support these beautiful hummingbirds.

Interesting Facts
– The orange cap on the head of the plain-capped starthroat is unique among North American hummingbirds. The related blue-throated mountain-gem found further south has a similar orange cap.

– Its scientific name commemorates French ornithologist Florent Prévost. The genus name Heliomaster refers to its preference for sun.

– The plain-capped starthroat pumps its tail while flying, a distinctive behavior seen in several Heliomaster hummingbirds. Scientists believe the pumping motion helps stabilize them in flight.

– The feathers on the plain-capped starthroat produce iridescent colors by refracting light off their microscopic structure rather than using pigments. The shape causes certain wavelengths to be reflected back producing pure emerald green.

– Like other hummingbirds, the plain-capped starthroat has remarkably high metabolism. At rest it takes about 250 breaths per minute and its heart rate can reach 1,260 beats per minute during flight.

In summary, with its bright orange cap and emerald green back, the plain-capped starthroat is a striking hummingbird endemic to Mexico’s western highlands. This energetic and territorial bird lives in mountain forests where it feeds on nectar using its specialized bill. Providing habitat through nectar plants and trees helps support these shimmering beauties.