The sheartail hummingbirds are a diverse group of tiny, colorful birds found exclusively in the New World. There are over 140 different species of sheartail hummingbirds, characterized by their short tails that are forked or end in pointed tips. These energetic, acrobatic flyers make up over a quarter of all hummingbird species. Their beauty, interesting behaviors, and vital ecological roles make them a fascinating group to study and observe.
Physical Characteristics
The sheartail hummingbirds get their descriptive name from their distinct tail shape. Unlike many hummingbird species with long, elegant plumes, sheartails have truncated or ‘sheared’ tails about half the length of other hummingbirds’ tails. Within the sheartail group, there is variation in precisely how the tail ends – some have deeply forked ‘V’ shaped tails, others have shallow forks, and some have pointed or spike-shaped tips. Despite their short tails, sheartails have relatively long wings like all hummingbirds.
In addition to tail differences, sheartails display incredible variation in colors and ornamentation. Iridescent throats, bellies, tails, and wing feathers create flashy, shining patches on males of most species. The Puerto Rican emerald, for example, has a bright green cap, blue-green throat, and white breast and belly. The amethyst-throated mountain-gem has an iridescent magenta throat and reddish-purple belly. Even females of many species display some striking colors on their throats or bellies. The wide array of hues and vivid, metallic sheens distinguish sheartails from many other backyard birds.
Sheartails are very small, ranging from 2 inches up to 8 inches in length. Despite their diminutive stature, they have high energy levels and fast metabolisms to power their constant hummingbird activities. They have specialized adaptations like reversible feet that allow them to perch adeptly on branches and feeders. Their long, specially-shaped beaks allow them to probe into flowers for nectar. Their wings can beat up to 75 times per second, enabling precise hovering and sudden aerial maneuvers.
Habitat and Behavior
The sheartail hummingbirds occupy a variety of habitats across the Americas. They are found in tropical rainforests, cloud forests, tropical scrublands, and even temperate mountain meadows and pine forests. Different species have adapted to specific ecological niches depending on factors like elevation, types of flowering plants, and climate. For example, the green-crowned brilliant prefers lowland tropical rainforests while the dusky starfrontlet inhabits cool, high-altitude forests. Due to their small size, sheartails can thrive in microclimates and isolated habitat patches that cannot support larger bird species.
Sheartails energetically flit through their preferred habitats feeding on nectar, defending territory, performing courtship displays, and more. They visit a continual circuit of blossoms through the day, favoring tubular and cup-shaped flowers that match their bill shape. Some species are trapliners that repeatedly visit the same productive flowers. They use their fast flying skills to chase off intruders from feeders or flowers in their territory. Males perform elaborate aerial displays, flying in arcs and circles to impress females. Their vocalizations include chatters, buzzes, and whistles.
Since sheartails live highly active lifestyles with fast metabolisms, they must feed frequently to fuel their bodies. They eat more than just sugary nectar, also catching small insects and spiders mid-air or picking them from vegetation. The extra protein boosts their nutrition. They play a vital role distributing pollen between plants as they gather nectar, pollinating tropical plant species along the way.
Threats and Conservation
Though sheartail hummingbirds thrive in diverse, complex habitats, they face mounting threats today. As human activities shrink and degrade their specialized habitat, some sheartail populations decline or disappear from areas they once occupied. For example, the Esmeraldas woodstar is endangered as coastal scrub habitat in Ecuador is cleared for agriculture. Other threats come from climate change, pesticide use, invasive species, and disruption of plant-pollinator relationships. Introduced bee species often outcompete native sheartails for nectar sources.
While the dynamic, fragmented populations of rare sheartail species require constant monitoring, research and conservation efforts today focus on protecting key habitats. Preserving intact rainforests, limiting destructive practices like logging and mining, and creating natural corridors all help maintain interconnected habitats. Providing flowering gardens with native plants can supplement nutrition. Careful hummingbird management and more natural landscaping practices help populations rebound. Given their beauty and ecological importance, with proper habitat stewardship, these special hummingbird species can continue thriving for generations to come.