Hummingbirds are some of the most fascinating birds in the world. Known for their ability to hover and fly backwards, hummingbirds have captured the imagination of people for centuries. While adult hummingbirds are brightly colored and easy to identify, young hummingbirds look quite different when they first leave the nest. In this article, we will explore what immature hummingbirds look like, how they develop their adult plumage, and how to identify fledgling hummingbirds.
What do hummingbird nestlings look like?
Hummingbirds build very small, cup-shaped nests out of plant down, spider webs, and lichens. The female lays two pea-sized white eggs in the nest, and incubates them for 14-23 days. When the chicks hatch, they are naked, blind, and completely helpless.
Newly hatched hummingbird chicks are about the size of a bumblebee. They have sparse white down feathers on their bodies but are otherwise naked. Their eyes are closed, and they have short non-functional beaks. Hummingbird chicks are altricial, meaning they hatch in an underdeveloped state and require extensive parental care.
The mother hummingbird feeds the chicks with regurgitated nectar and insects. She works tirelessly, feeding the chicks every 20 minutes from dawn to dusk. After about a week, the chicks’ eyes open and pinfeathers start growing in. By 2-3 weeks old, they have enough feathers to regulate their temperature and look more like juvenile hummingbirds.
Plumage changes as hummingbirds mature
As hummingbirds grow and mature, their plumage goes through distinct changes:
Nestlings
– Naked body with sparse white down
– Eyes closed
– Non-functional beak
– Helpless, altricial
Fledglings
– Covered in downy body feathers
– Short tail feathers grown in
– Eyes open, more alert
– Short non-functional beak
Juveniles
– Contour feathers replace down
– Tail and wing feathers nearly full length
– Able to fly short distances
– Female and male juveniles look similar
Immatures
– Full set of flight feathers
– Able to feed themselves
– Adult plumage starts growing in patches
– Males may show some color on throat
Adults
– Full adult plumage attained
– Bright iridescent throat and crown (males)
– White tipped outer tail feathers
– Able to reproduce and nest
The progression from nestling to adult takes between 3-5 weeks for most hummingbird species. The duration depends on factors like the species, food availability, and latitude. Hummingbirds that live farther north take longer to mature since they hatch later in spring.
How to identify fledgling hummingbirds
Fledgling hummingbirds have left the nest and are still developing flight skills and independence. Here are some tips for identifying young fledglings:
– Lots of downy body feathers, stubby tail, and wispy head feathers
– Move from branch to branch clumsily, cannot hover or fly long distances
– Make raspy peeping calls, especially when begging for food
– May have short tail quills or emerging pinfeathers on head and wings
– Dull gray/brown overall, no bright adult plumage or iridescence
– Will return to the nest or safe perches each night
– Parents continue to feed and protect the fledgling
Young fledglings often appear on the ground, having fallen from the nest prematurely. If the bird is uninjured, the best option is to leave it there or return it to a nearby bush. The parents will continue to care for it.
Why do juvenile hummingbirds look different?
There are a few key reasons why immature hummingbirds don’t have their adult colors right away:
Camouflage
Dull, mottled feathers provide camouflage for young hummingbirds in the nest and while learning to fly. Without bright colors, they are less visible to potential predators.
Energy conservation
Growing colorful feathers takes a lot of energy and nutrients. Juvenile plumage allows young hummingbirds to focus resources on developing flight muscles and foraging skills rather than decorative feathers.
Sexual maturity
Adult male hummingbirds use their brilliant feathers to attract females. Since juvenile males are not sexually mature, they do not need breeding plumage right away. Their energies go toward learning to feed and survive.
Molting process
Hummingbirds molt and replace all their feathers at least once per year. Growing colorful new feathers takes time and happens gradually after the juvenile body feathers are established.
Changes in beak and tongue structure
Along with feather changes, hummingbird beaks and tongues transform as they mature:
Nestlings
– Short non-functional beaks – relied onparent for feeding
Fledglings
– Begin catching small insects but cannot access nectar
Immatures
– Tongues start developing nectar-lapping tips
– Beaks lengthen to match tongue and reach nectar
Adults
– Full double-tubed extensible tongues
– Needle-like beaks adapted to specific flower shapes
It takes practice and development for young hummingbirds to efficiently feed on nectar with their unique tongues and beaks. Accessing different flower shapes helps complete this maturation process.
Role of molting in hummingbird development
Molting is the process by which birds shed old worn feathers and grow new ones. Hummingbirds molt several times through juvenile development:
Natal down molt
Shedding of wispy chick down and replacement with juvenile contour feathers. At 2-3 weeks old.
First prebasic molt
Partial molt of body feathers before the first winter. At 2-4 months old.
First basic molt
Complete molt of all feathers, gaining some adult plumage. At 6-14 months old.
Second prebasic molt
Another partial molt of some feathers. At 10-15 months old.
Definitive prebasic molt
Final molt to full adult plumage. Between 12-18 months old.
This molting schedule allows hummingbirds to gradually transition from their juvenile camouflage feathers to brilliant adult coloring over their first 1-2 years of life. The energy demands of repeated molting are substantial.
Interesting facts about young hummingbirds
Here are a few fascinating facts about immature hummingbirds:
Rapid growth
Hummingbirds grow incredibly fast. Nestlings can gain up to 30% of their hatch-weight per day. They reach full adult size in just 2-4 weeks.
High mortality
Up to 50-70% of juvenile hummingbirds may not survive to adulthood. Many succumb to predators, insufficient food, or cold weather.
First migration
Most hummingbirds migrate as juveniles before acquiring full adult plumage. For example, fledgling Rufous Hummingbirds migrate solo from Alaska to Mexico.
Record holders
The Calliope Hummingbird molts all its feathers the fastest in just 3 weeks. Anna’s Hummingbirds can reproduce at only 1 year old, the youngest of all North American hummers.
Nest departures
Hummingbird nestlings fledge earlier in northern regions compared to southern ones. This ensures they can mature and put on fat before migrating south.
The speedy transformation from helpless hatchling to colorful adult is an incredible feat of nature. Tracking hummingbird development reveals their resilience and adaptability to survive in diverse habitats.
Conclusion
While adult hummingbirds are jewel-toned wonders, young hummingbirds look remarkably different. Newly hatched chicks are nearly naked; they develop down feathers and eventually juvenile plumage as they grow. It takes 1-2 years and several molting cycles for them to attain colorful adult feathers. Drab patterns initially provide camouflage and conserve energy. Hummingbird tongues and beaks also transform to allow nectar-feeding. Understanding the different life stages provides insight into hummingbird biology and development. With patience, even young hummingbirds with stubby tails will mature into their full nimble-flying splendor.