Lophornis brachylophus
The Blue-capped Hummingbird, also known as the Oaxaca Hummingbird, is a stunning species of the Mexican highlands, a shimmering assemblage of vibrant contrasting colors. The male’s deep violet-blue crown is nearly overshadowed by the stream of shining green that runs like emerald sequins from his chin to his belly. This gem among birds is unique to a small stretch of forested foothills in the Sierra Miahuatlán mountains, part of the larger Sierra Madre del Sur range in southern Mexico.
Perhaps in part because of its limited range, this mysterious endemic has largely flown under the radar for biologists. Only known to science since 1964, the Blue-capped Hummingbird has yet to be the subject of a dedicated study. As a result, many basic aspects of its biology and life history remain unknown.
The Blue-capped Hummingbird owes its shining green and blue plumage not to pigment, but to the microscopic structure of the feathers’ surfaces. Each tiny thread that makes up the plumes of these feathers is covered with layers of complex arrangements of air pockets and light-absorbing cells called melanosomes that collectively work together to reflect only the slimmest bandwidth of color — in only one direction. This phenomenon, known as “structural color,” is also the reason that most of the Blue-capped Hummingbird’s stunning plumage looks nearly black if viewed from the wrong angle. These feathers are so good at absorbing light that they reflect almost nothing but the desired color. Hummingbirds also have direct control of the angle that these feathers, and their shining reflectance, face. If the hummer isn’t directing his light at us, what we see is essentially the absence of light.
As with so many tropical birds of Central and South America, the chief threat to the Blue-capped Hummingbird is habitat loss resulting from deforestation. Habitat loss is a particularly grave concern for this and other birds with small geographical ranges. There simply isn’t that much habitat to begin with, and any losses have an outsized impact on the species as a whole.
Deforestation is a serious threat to wildlife throughout Mexico. Since the 1960s, agriculture has spread across the Sierra Miahuatlán, the mountain range that encompasses the entire range of the Blue-capped Hummingbird. Unlike shade coffee plantations, which can provide some habitat for this and other hummingbird species, corn and citrus crops entirely replace the native vegetation that these birds need to survive.
The Blue-capped Hummingbird needs our help to overcome the threats it faces. At ABC, we’re inspired by the wonder of birds and driven by our responsibility to find solutions to meet their greatest challenges. With science as our foundation, and with inclusion and partnership at the heart of all we do, we take bold action for birds across the Americas.
Habitat is the foundation for birds’ survival. With ABC’s support, Mexican NGO Conservación Biológica y Desarrollo Social (CONBIODES) is reaching out to communities where the Blue-capped Hummingbird lives to promote the establishment of voluntary protected areas, or Áreas Destinadas Voluntariamente a la Conservación (ADVCs). Working with dozens of partners and local communities throughout Latin America and the Caribbean, ABC supports a growing network of protected areas in more than a dozen countries. Totaling more than 1.3 million acres, nearly one-third of the world’s birdlife (more than 3,000 species) is protected by an ABC-supported reserve.
The Blue-capped Hummingbird has also been identified as a priority species in ABC’s Gap Analysis — a review of habitat protection for Latin America’s most threatened species. It is among just 10 species currently lacking adequate habitat protection based on population size, but protecting this gem in Oaxaca is a goal within reach. ABC is partnering with CONBIODES to monitor birds throughout the southern highlands of the state of Oaxaca to improve our understanding of the distribution of this species. By better understanding its range and habitat needs, we can better direct our efforts to conserve it.
With his dark violet-blue forecrown, the male Blue-capped Hummingbird is accurately named, but there is much more to his stunning plumage than this one patch of color. Behind his namesake cap, the rest of the male’s crown is an iridescent light blue to turquoise. The back, shoulders, and base of the tail are an iridescent golden green. Equally impressive as the purple-blue head feathers, the male’s throat, breast, and belly are covered in a shimmering array of shining scale-like green feathers. A patch of red-orange feathers on the wings provides a brilliant contrast, while the strikingly pure white tail provides another. Females are similar, but the underparts are pale gray, and the dark purple-blue at the front of the crown is replaced by an extension of the turquoise covering the rest of her head. Altogether, truly a stunning bird
The Blue-capped Hummingbird’s vocal behavior has not been thoroughly described, and there are few sound recordings available. The male’s song is a jumbled stream of high-pitched percussive notes with the occasional squeak mixed in, delivered rapidly but in a halting manner with pauses interspersed. The male and female both give a dry insect-like call, usually as a series of quick nasal buzzes.
Credit: Blue-capped Hummingbird by Andrew Spencer; Cornell Lab of Ornithology | Macaulay Library. Accessible at https://macaulaylibrary.org/asset/47648261.
Credit: Richard C. Hoyer, XC96541. Accessible at www.xeno-canto.org/96541.
The Blue-capped Hummingbird uses several different forest types within the mountains that encompass its geographical range. It favors cloud forest and the upper edges of tropical semi-deciduous forest, in addition to pine-oak forest and shade coffee plantations.
Specific Area
Sierra de Miahuatlán, Oaxaca, Mexico
Range Detail
The Blue-capped Hummingbird is endemic to the Mexican state of Oaxaca, where it is limited to the Pacific slope of the Sierra de Miahuatlán. A species of montane forests, this bird is mostly limited to elevations between 2,300 and 8,500 feet.
Did you know?
The Blue-capped Hummingbird was formerly considered a subspecies of its closest relative, the White-tailed Hummingbird. The two species mostly seem to share the same diet and habitat preferences, and their ranges overlap, but the White-tailed lacks the striking purple-blue crown.
Though visually stunning, few researchers have undertaken dedicated studies of the Blue-capped Hummingbird, and little of its basic biology has been described. Much remains to be discovered about this marvelous species, as long as it survives long enough for us to do so.
Like other hummingbirds, the Blue-capped feeds primarily on the nectar of various tropical flowers. The Blue-capped probably also eats insects, although this has not been described in the literature.
Researchers have not formally described courtship in the Blue-capped Hummingbird. Courtship across the hummingbird family is diverse, incorporating songs, aerial displays, and flashy dance moves that show off their striking colors.
The Blue-capped Hummingbird’s breeding behavior is poorly known; only a few nests have been described. These nests were open cups made mostly of moss and lichens, bound with spiderweb, and lined with downy materials from plants. The female probably builds the nest alone, as with other hummingbird species.
Only two nests have been described in the literature. In these nests, the female laid two eggs, which is typical of many hummingbird species.
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