The Azure-crowned Hummingbird (Amazilia cyanocephala) is a small hummingbird found in Mexico and the southwestern United States. With its vibrant green-blue crown and throat, it is one of the most colorful hummingbirds in North America. This article will provide an overview of the Azure-crowned Hummingbird, including its description, taxonomy, geographic range, habitat, diet, behavior, breeding, conservation status, and unique traits that make it stand out among hummingbirds.
Description
The Azure-crowned Hummingbird measures 3.5-4 inches in length and weighs 2-3 grams on average. The male has a brilliant turquoise-blue crown and throat, with the color extending slightly below the eyes. The rest of the head, upperparts and underparts are green. The tail is rounded and green with a dark subterminal band. The female is similar but less vibrant, with green replacing the blue on the head and throat. The bill of both sexes is straight and black. The Azure-crowned Hummingbird’s small size, agile flight and iridescent feathers distinguish it from other North American hummingbirds.
Taxonomy
The Azure-crowned Hummingbird belongs to the family Trochilidae and the genus Amazilia. It was first described by the French ornithologist Rene Primevere Lesson in 1829. Its scientific name Amazilia cyanocephala combines the Latin words cyanocephalus meaning “blue-headed” and the Greek amazein meaning “to flutter”. Its closest relative is the Berylline Hummingbird, and the two were considered conspecific until recent genetic analysis showed they were distinct species. Four subspecies of the Azure-crowned Hummingbird are recognized today across its range: A. c. cyanocephala, A. c. niveiventris, A. c. devillei and A. c. graysoni.
Geographic Range
The Azure-crowned Hummingbird ranges across the mountains of Mexico as far south as Guerrero. Its breeding range extends north into the southwestern United States, including southeastern Arizona, southern New Mexico and western Texas. Rare vagrants have been spotted as far north as Canada. The species is partially migratory, with northern populations migrating south to wintering grounds in Mexico. Southern residents may remain year-round in breeding areas. Ideal habitat consists of canyons, foothills and montane woodlands near flowering plants.
Habitat
Azure-crowned Hummingbirds are found in a variety of semi-open habitats, including oak or pine-oak woodlands, mountain canyons, scrubland, and suburbs or parks with sufficient vegetation and flowers. They occur at elevations between sea level and 8000 feet. While other Amazilia hummingbirds prefer tropical climates, the Azure-crowned thrives in temperate regions. It prefers areas with blooming agaves and other nectar plants and trees that provide insects and perches.
Diet
Like all hummingbirds, the Azure-crowned Hummingbird feeds primarily on nectar from flowers and flowering trees. It favors flowers with tubular shapes that accommodate its long, slim beak. Examples include sage, aloe, trumpet vines and ocotillo. The species also gleans insects and spiders from leaves and bark to meet its protein requirements. Insects may constitute up to a third of its total food intake. A specialized tongue with forked tips allows the bird to lap up nectar and catch insects.
Behavior
The energetic, territorial Azure-crowned Hummingbird defends flowering shrubs and trees against intruders. Males perform aerial displays and aggressive chases to ward off rivals. Dominant males maintain feeding territories, while females and young males visit more briefly. The Azure-crowned Hummingbird’s small size allows it great agility and maneuverability in flight. Wings beat up to 50 times per second, enabling the bird to hover in midair and fly in any direction. At night, it enters a mild state of torpor to conserve energy. The species has a variety of vocalizations including high-pitched squeaks and squeals.
Breeding
The breeding season of the Azure-crowned Hummingbird varies across its range. Northern populations breed from March to July, with some initiating courtship in late February. Further south, breeding may occur year-round. Males court females through aerial displays over breeding sites. After mating, the female builds a tiny cup-shaped nest out of plant down, spider silk and lichen on a branch or stem. She incubates the 2 pea-sized white eggs for 14-16 days until hatching. Chicks fledge in another 18-23 days. The female cares for the young though the male may participate in feeding once they leave the nest. Most chicks do not survive to adulthood. Adult hummingbirds have remarkably long lifespans for their size, with averages of 3-5 years reported in the wild.
Conservation Status
The Azure-crowned Hummingbird has a large range estimated at more than 60,000 square miles. Partners in Flight estimates the global breeding population at 1.5 million, with 97% spending some part of the year in the U.S. While thriving in many regions, numbers in Arizona declined by over 50% from the 1960s to the 1990s. Habitat loss, reduced flower availability and hotter, drier conditions due to climate change pose ongoing threats across its range. The species is classified as Least Concern by the IUCN Red List due to its abundance over most of its territory. Maintaining suitable habitat across elevations, limiting pesticide use, and providing artificial food and water during dry periods may help conserve Azure-crowned Hummingbird populations.
Unique Traits
– One of the most cold-tolerant hummingbird species, withstanding freezing temperatures and snowfall during winters and high elevations.
– Males have an elaborate diving display not seen in other North American hummingbirds, plummeting from heights of 130 feet or more before pulling up.
– Produces a distinctive metallic “zeep” call multiple times per second when pursuing intruders or defending resources.
– Periodically spreads wings and fans tail while perched, possibly to remove dust or regulate temperature.
– The flattened outer primary wing feathers produce the signature hummingbird hum during flight. Wings beat 55 times a second on average.
– Nests have the smallest volume relative to body size of all hummingbirds. Incubation lasts 14-16 days, hatchlings fledge in 18-23 days.
– Like all hummingbirds, the Azure-crowned feeds by trap-lining, moving methodically among preferred flower patches. Territory sizes average 0.2 acres.
– An important pollinator of ocotillo, agave, penstemon, firecracker flowers, and other southwestern nectar sources.
– With a specialized grooved tongue and ability to hover, it can obtain nectar from flowers not accessible to other pollinators.
In summary, the beautiful Azure-crowned Hummingbird is a unique resident of the southwestern U.S. and Mexico. Its shimmering blue crown is unmistakable as it visits mountain canyons and woodlands in search of nectar and insects. Despite declining locally in some areas, global populations appear stable. Maintaining natural areas with diverse floral resources can help ensure the future of this hardy, aerial jewel. With its remarkable adaptations, energetic display flights, and important ecological role, the Azure-crowned Hummingbird remains a treasured component of southwestern ecosystems.