Pelicans are the large water birds which belong to family Pelecanidae. Pelicans come under the order Pelecaniformes, which is also the order of other sea birds like gannets, boobies, cormorants, frigatebirds, darters and and tropicbirds. Pelicans are found in warm regions. They live on coastal waters and inland. They inhabit on all continents except Antarctica.
Pelicans are relatively large birds. Its smallest species of it is Brown Pelican, which can be as small as 2.75 kg (6 lb) in weight and 106 cm (42 in) in length. It has a short wingspan of 1.83 m (6 ft). Its largest species is Dalmatian Pelican which can have 15 kg (33 lb) weight, 183 cm (72 in) length and 3.5 m (11.5 ft) of wingspan. The Australian Pelican has the longest bill compared to any bird.
The distinctive characteristic of pelican is that they have a pouch under the beak. They have short and strong legs with all toes webbed. They have a short square shaped tail including 20 to 24 feathers. Pelicans have relatively long wings. They also include 30 to 35 secondary flight feathers which is not common in all birds.
A special fiber present deep in their breast muscles helps them to hold wings horizontal while gliding. To commute over 150 km (100 miles) to feeding areas, pelicans exploit thermals. To keep their plumage waterproof, pelicans rub backs of their heads where the preen glands are present, which secrets the oil.
Pelicans mainly live on eating fish, but also eat crustaceans, amphibians and even smaller birds even. They catch fish by expanding their throat pouch. After catching, they drain their pouch before swallow the prey. This procedure takes up to a minute, by the time other sea birds may steal their prey from them. However in turn, pelicans also steal the prey from other sea birds.
The white pelicans hunt their prey in groups. They stand in line to hunt a school of fish. They catch a large fish by bill-tip, toss them in air to caught it and then slide into the gullet. However the brown pelican dive into the water to catch the fish. The other species (Peruvian Pelican and Australian Pelican) also practice this method.
Pelicans are colonial birds. In ground nesting species, problem occurs during breeding because group of males chase for a single female. However in tree nesting species a perched male advertise for females.
After pairing the copulation begins and continues for 3 to 10 days before egg-laying. A male bird brings the nesting material in bill or in pouch to build their nests. These birds lay at least two eggs in the nest. The parent eggs together incubate the eggs on top of or below the feet. The young bird takes 10 to 12 weeks after hatching to become mature.
The extant species of pelican are given below with their binomial name:
- Brown Pelican (Pelecanus occidentalis)
- Australian Pelican (Pelecanus conspicillatus)
- American White Pelican (Pelecanus erythrorhynchos)
- Great White Pelican (Pelecanus onocrotalus)
- Dalmatian Pelican (Pelecanus crispus)
- Peruvian Pelican (Pelecanus thagus)
- Pink-backed Pelican (Pelecanus rufescens)
- Spot-billed Pelican (Pelecanus philippensis)
We can divide pelicans in two groups according to color of their plumage and their nesting type. Those who have white adult plumage and nest on ground are American White, Australian, Great White and Dalmatian Pelicans. However, the other group of Peruvian, Spot-billed, Pink-backed and Brown Pelican have gray or brown plumage and are nest in trees. The Peruvian Pelican is sometimes considered similar to the Brown Pelican.