There are seven species of pelicans in the world, all of which are similar in shape and, with one exception, are primarily white in colour. Males are larger than females. The most characteristic feature of pelicans is the elongated bill with its massive throat pouch. The bill is 40 - 50 cm long and is larger in males than females.
Pelicans weigh 4.0 - 6.8 kg, are 1.6 - 1.8 m long. Pelicans have large wings and a wingspan of 2.3 - 2.5 m. They have an extremely light skeleton, weighing less than 10% of their total body weight.
The Australian Pelican Pelecanus conspicillatus isfound throughout Australia, Papua New Guinea and western Indonesia, with occasional reports in New Zealand and various western Pacific islands. In Australia it is widespread on freshwater, estuarine and marine wetlands and waterways including lakes, swamps, rivers, coastal islands and shores.
Pelicans mainly eat fish, but they are opportunistic feeders and eat a variety of aquatic animals including crustaceans, tadpoles and turtles. They readily accept 'handouts' from humans, and a number of unusual items have been recorded in their diet. During periods of starvation, pelicans have been reported capturing and eating seagulls and ducklings. The gulls are held under water and drowned before being eaten headfirst. Pelicans will also rob other birds of their prey.
The bill and pouch of pelicans play an important role in feeding. The bill is sensitive and this helps locate fish in murky water. It also has a hook at the end of the upper mandible, probably for gripping slippery food items. When food is caught, the pelican manipulates it in its bill until the prey typically has its head pointing down the pelican's throat. Then with a jerk of the head the pelican swallows the prey.
The pouch does not function as a place to hold food for any length of time. Instead it serves as a short-term collecting organ. Pelicans plunge their bills into the water, using their pouches as nets. Once something is caught, a pelican draws its pouch to its breast. This empties the water and allows the bird to manoeuvre the prey into a swallowing position. The pouch can also serve as a net to catch food thrown by humans, and there are sightings of pelicans drinking by opening their bill to collect rainwater.
The bill is delicately built. The lower jaw consists of two thin and weakly articulated bones from which the pouch hangs. When fully extended, the bill can hold up to 13 litres.
The Australian Pelican may feed alone, but more often feeds as a cooperative group. Sometimes these groups are quite large. One group numbered over 1,900 birds. A flock of pelicans works together, driving fish into a concentrated mass using their bills and sometimes by beating their wings. The fish are herded into shallow water or surrounded in ever decreasing circles.
Pelicans are highly mobile, searching out suitable areas of water and an adequate supply of food. Pelicans are not capable of sustained flapping flight, but can remain in the air for 24 hours, covering hundreds of kilometres. They are excellent soarers and can use thermals to rise to considerable altitudes. Flight at 1,000m is common, and heights of 3 000 m have been recorded. By moving from one thermal to the next, pelicans can travel long distances with a minimum of effort, reaching air speeds of up to 56 km/hour.
Pelicans are colonial breeders with up to 40 000 individuals grouping on islands or secluded shores. Breeding may occur at any time of year depending on environmental conditions, particularly rainfall.