Pelicans are large aquatic birds known for their distinctive long beaks and expandable throat pouches. These features are primarily used for catching fish. Pelicans are found globally in various aquatic environments, including fresh, brackish, and saltwater habitats, often congregating in coastal regions, lakes, and rivers. They are highly social birds, frequently observed in flocks, and some species cooperate during feeding by herding fish into shallow waters.
Roosting Locations
Pelicans typically choose specific roosting sites for sleeping, which vary depending on the species and local environment. Natural habitats include secluded islands, sandbars, and rocky islets, providing isolation from predators. Coastal mangroves and trees are common roosting spots for some species, such as brown pelicans, while white-plumaged species often prefer open ground. Artificial structures also serve as night roosts, including jetties, docks, buoys, and abandoned structures, offering elevated and stable resting places. These sites are important for pelicans to rest and perform maintenance, particularly dry spots since pelicans cannot remain on water for extended periods without becoming waterlogged.
Factors for Roosting Site Selection
Roosting site selection is influenced by factors prioritizing safety and well-being. Isolation from predators is a primary concern, with islands and elevated structures providing natural barriers against land-based threats. Sites are often chosen for proximity to abundant feeding grounds, minimizing energy expenditure for daily foraging flights. This allows effective commuting between resting and hunting areas, even over considerable distances.
Shelter from harsh weather, such as strong winds or storms, also plays a role. Pelicans seek locations offering protection and stability during adverse weather. Suitable perches or sufficient ground space for large numbers of birds are important, as pelicans often roost in communal groups. Group roosting enhances safety through collective vigilance and aids thermoregulation, helping birds conserve warmth.
Sleeping Behaviors and Patterns
Pelicans are diurnal, primarily active during the day, and sleep at night. When sleeping, pelicans commonly adopt specific postures. They often rest on land, either standing or hunkering down on their breasts. A frequent sleeping posture involves tucking their long bill up onto their back, providing insulation and resting neck muscles.
Pelicans often sleep in large groups, a social behavior offering increased protection from disturbances. While generally silent, colonies can become noisy, particularly during breeding seasons. Although land is preferred for safety and comfort, pelicans have been observed sleeping while floating on calm water in certain conditions. Some birds, including pelicans, are capable of unihemispheric slow-wave sleep, where one half of the brain rests while the other remains alert, allowing vigilance against threats even during sleep.