Pelicans are large waterbirds known for their distinctive large beaks and throat pouches used for catching fish. There are eight living species of pelicans that are found on every continent except Antarctica. Juvenile pelicans look quite different from adult pelicans, going through several distinct phases before reaching full adult plumage.
Newly Hatched Pelicans
When pelicans first hatch from their eggs, they are completely dependent on their parents for food and protection. Hatchlings are covered in white or gray down feathers. Their eyes are closed at first, only opening after several days. Their bills are short and straight at this stage, lacking the hook at the end that develops as they grow. Their feet and legs are disproportionately large compared to their body size. Hatchlings weigh only around 3-4 ounces and are very vulnerable.
Parent pelicans protect the hatchlings and shade them from the sun. They feed the chicks by regurgitating food into their gaping mouths. Hatchlings stay in or near the nest for their first 2-3 weeks of life, being brooded by their parents to keep them warm.
Developing Juveniles
After 2-3 weeks, juvenile pelicans start to grow juvenile feathers called mesoptiles. These feathers start to replace the downy feathers. The mesoptile feathers are gray, brown, or white depending on species. The bill lengthens and starts to curve downward at the tip. The eyes change from gray to the species-specific adult eye color. Legs get thinner and lose their disproportionate size.
At this stage, juveniles start wandering from the nest and exploring their surroundings. They can swim short distances. Parents still feed them regurgitated food. Plumage starts to take on more adult-like appearance.
Fledglings
Around 6-10 weeks after hatching, juvenile pelicans develop enough to leave the nest and fly short distances. At this fledgling stage, their flight feathers have grown in but their tails are short. They can feed themselves by plunge diving, but are not very good at catching fish yet compared to adults. Their bills are still shorter and straighter than an adult’s bill.
Fledglings assemble in small groups with other young pelicans while their parents are off fishing. They practice flying, swimming, and feeding in these groups known as pods or crèches. Their grayish plumage provides camouflage from potential predators.
Immature Plumage Phase
After leaving the nest for good, juvenile pelicans go through an immature plumage phase that can last over a year. Their appearance changes slowly during this time. The bill continues growing and develops the hooked tip. Plumage very slowly acquires the distinctive species-specific patterns of adults, often starting with dark patches on the head and back. However, juveniles lack the bright yellow, pink, or orange facial skin and pouch colors of breeding adults. Their plumage remains duller than adults.
During this long phase, immature pelicans hone their fishing skills and learn to catch their own food. They may still associate in loose groups. Their range expands as they learn to fly longer distances.
Acquiring Adult Plumage
Right before reaching sexual maturity at 2-3 years old, juvenile pelicans finally molt into their full adult plumage. This happens just in time for their first breeding season. The bill reaches maximum length. Vibrant pink, orange, or yellow skin and pouch colors develop. Plumage becomes vividly colored and patterned. Last tail feathers grow in to attain full length.
Now juvenile pelicans take on the appearance of mature adults. Adult males and females look alike in most pelican species, although the males are slightly larger on average. After molting into adult plumage, pelicans are ready to stake out a nesting territory, find a mate, and raise their own chicks.
Appearance Changes By Species
While all pelicans go through the same general phases, the details of their appearance changes depends on the species:
American White Pelican
- Hatchlings: Gray down feathers, pink bill with short straight tip
- Juveniles: Grayish-brown feathers, dull orange billdevelops downward hook
- Immatures: White feathers slowly acquire black wing tips, bill turns pale yellow
- Adults: Entirely white except for black wing tips, bright orange bill and pouch
Brown Pelican
- Hatchlings: Gray down, short straight bill
- Juveniles: Grayish-brown plumage, grayish bill curves downward
- Immatures: Plumage becomes dark brown, bill yellowish
- Adults: Distinctive white neck and head, bright yellow bill
Peruvian Pelican
- Hatchlings: White down, pinkish bill with short tip
- Juveniles: Brownish-gray plumage, pale bill curves down
- Immatures: Pinkish wash on neck, bill darkens to grayish
- Adults: White with chestnut markings on neck, gray bill with red tip
The various pelican species follow this same general pattern of appearance changes from hatchling to adult, but the timing and details vary by species. The progression shows how juvenile pelicans slowly transition to the recognizable forms people commonly associate with these large seabirds.
Why Do Juvenile Pelicans Look Different?
There are several theories as to why juvenile pelicans look so different from their adult counterparts:
- Drab camouflaging plumage helps protect vulnerable chicks and fledglings from predators.
- Subdued bill coloration may help juveniles blend in when diving for fish.
- Straight bill shape allows easy feeding by parents.
- Gradual changes spread out energetic costs of growth over time.
- Delayed maturation of breeding plumage reduces competition for mates.
By going through distinct phases, juvenile pelicans likely gain survival advantages that improve their chances of living to adulthood and breeding successfully. The more experienced and capable they become, the more their appearance shifts towards bold adult breeding plumage.
Conclusion
Juvenile pelicans have a markedly different appearance from their adult counterparts. Newly hatched chicks are vulnerable and rely on camouflage and parental care. As they grow and develop skills, their plumage and bill slowly acquire adult features. Full maturation happens right before they are ready to breed. Their changing appearance seems adapted to help young pelicans survive to adulthood.
