Hummingbirds are known for their bright, iridescent plumage that shimmers in the sunlight. However, juvenile hummingbirds often look quite different from their adult counterparts. When hummingbirds first hatch from the egg, their feathers lack the vibrant colors of maturity. Instead, their downy coat helps camouflage them in the nest. As they grow, young hummingbirds go through several molts, gradually attaining their adult feathers. The pace of this maturation varies by species.
Newly Hatched Hummingbirds
Hummingbird nestlings hatch with only a thin covering of downy feathers. These feathers are designed to insulate and camouflage, not display color. At this stage, hummingbird chicks may appear relatively drab, with gray, brown, or white down. Without their flashy plumage, young hummingbirds blend into their nest environment. Their underdeveloped feathers also allow close contact with their mother, facilitating warmth and feeding.
Within a few days, hummingbird chicks undergo a growth spurt. As they grow, their juvenile true feathers start to emerge from under the downy coat. True feathers have a central shaft with interlocking barbs and barbules. Still, juvenile feathers lack the structural coloration that creates the iridescent, metallic sheen of adult plumage.
Fledgling Plumage
After 2-3 weeks in the nest, young hummingbirds prepare to fledge. At this stage, their first true plumage has grown in. While still less vibrant than adult feathers, fledgling plumage shows more coloration than the original down coat. Within a species, males and females may display similar fledgling plumage. It provides necessary camouflage at a vulnerable stage when the young birds are still learning to fly and feed.
For example, fledgling Ruby-throated Hummingbirds have gray-green heads, backs, and wings. Their throat and breast show a muted white stripe and wash of pale reddish-brown. Fledgling Allen’s Hummingbirds have bronze-green backs with a pale yellow underside. In many species, the tail feathers at this stage have white tips.
| Species | Fledgling Plumage |
|---|---|
| Ruby-throated Hummingbird | Gray-green head, back, and wings. Pale reddish-brown throat and breast. |
| Allen’s Hummingbird | Bronze-green back with pale yellow underside. |
While less colorful than adults, fledglings’ plumage still shows sex differences in some dimorphic species. For instance, fledgling male Ruby-throats can be distinguished from females by faint markings on the throat and tail shape.
Post-Fledging Molts
In the first weeks after leaving the nest, fledgling hummingbirds continue to grow and molt. They undergo a partial post-fledging molt, replacing many body feathers and some flight feathers. The timing varies by species and individual. For example, Ruby-throats molt head and body feathers within a month of fledging but may replace their wing and tail feathers over 2-3 months.
During this molt, fledglings gain more colorful adult-like plumage. Male Anna’s Hummingbirds attain rose-pink head and throat feathers by 6-8 weeks post-fledging. Male Allen’s develop their distinctive orange-red throat and crown. In females and some species, juvenile plumage resembles a subdued version of adult colors.
This transitional phase allows young hummingbirds to test their flying skills while still benefiting from some camouflage. Their maturing feathers also help regulate body temperature during the high energy demands of growth.
Example post-fledging changes:
| Species | Fledgling Plumage | Post-Fledging Changes |
|---|---|---|
| Anna’s Hummingbird | Mostly grey-green with pale below | Males gain rose-pink head and throat |
| Allen’s Hummingbird | Bronze-green back, pale yellow below | Males develop orange-red throat |
Definitive Basic Plumage
By 2-3 months post-fledging, most juvenile hummingbirds have acquired their basic non-breeding or definitive basic plumage. This resembles the adult plumage but is generally less vibrant, with muted or incomplete color patches.
For example, juvenile male Anna’s attain dusky rose-red throats like adult females. Their crown and tail feathers show hints of rose-pink. Meanwhile, young male Calliope Hummingbirds have elongated central tail feathers and bright purple-red throat feathers. Yet their gorget still lacks the full magenta color and glittery texture of mature males.
In less dimorphic species, juvenile males may be indistinguishable from adult females. For instance, young and female Rufous Hummingbirds both have green backs with a wash of rufous on the sides, tail, and wings.
One exception is the Ruby-throated Hummingbird. Ruby-throat males complete their molt before fall migration. By this point, their first plumage is brilliant red with minimal differences between juveniles and adults.
Examples of definitive basic plumage:
| Species | Definitive Basic Plumage |
|---|---|
| Anna’s Hummingbird | Males have dusky rose-red gorgets |
| Rufous Hummingbird | Males and females green with rufous wash |
| Ruby-throated Hummingbird | Males attain bright red adult gorgets |
First Breeding Plumage
In their first breeding season after hatching, juvenile hummingbirds complete another molt. This yields their first breeding or nuptial plumage. While still not as vibrant as older adults, one-year-olds display much more brilliant, colorful feathers for courtship.
By their second breeding season, most hummingbirds appear identical to older adults in breeding plumage. However, some subtle differences in feather quality and iridescence remain. For instance, the collar on a two-year-old male Anna’s may not glow as strongly purple-red under certain light angles.
Intriguingly, some juvenile hummingbirds appear to skip the duller basic plumage stage. Instead, they molt directly into adult-like breeding plumage before their first breeding season. For example, young male Allen’s Hummingbirds may acquire full red-orange gorgets within months of fledging.
Examples of first breeding plumage:
| Species | First Breeding Plumage |
|---|---|
| Anna’s Hummingbird | Males have brighter gorgets than basic plumage |
| Allen’s Hummingbird | Some males gain full red-orange gorgets |
Conclusion
In summary, juvenile hummingbird plumage goes through several distinct phases. Nestlings hatch with downy, camouflaged fuzz. Fledglings gain some color but still resemble females or lack full adult plumage. After fledging, a partial molt produces definitive basic plumage. In their first breeding season, another molt results in bright nuptial plumage, completing the transition to maturity. So while adult hummingbirds dazzle with their iridescent colors, young hummingbirds need time to grow into their spectacular feathers.
