elecanidae’ that possess a distinctive pouch under the beak.However, the smallest of this bird species, although it is a large bird in nearly every other regard, is the Brown Pelican which is listed among the hundreds of birds that are known inhabitants of Guyana’s forests.In agreement with their purported small size, these pelicans can weigh as little as 2.75 kilogrammes (kg) with lengths of about 106 centimetres (cm) when compared to the largest pelicans which can weigh up to 15 kg and has lengths of about 183 cm.They are said to have a short and square tail which has about 20 to 24 feathers.Their wings, which are long and have the unusually large number of 30 to 35 secondary flight feathers, have a span of about 1.83 metres.It has been discovered that a layer of special fibres deep in the breast muscles can hold the wings rigidly horizontal for gliding and soaring. As a result it is said that they are able to exploit thermals to commute over 150 km to feeding areas.And like all other pelicans, they can swim just as well with their short, strong legs and their four-toed webbed feet.The regular diet of a pelican usually consists of fish but they also eat amphibians,Wholesale Cheap Jerseys, crustaceans and on some occasions, smaller birds.Reports are that a pelican swallowed a living pigeon in St James Park in London in October 2006. According to tourists who witnessed the occurrence, the pelican strolled over to the pigeon and grabbed it into its beak which resulted in a 20-minute long struggle that ended with the pigeon being swallowed head first flapping all the way down the pelican’s throat.It is said that pelicans often catch fish by expanding their throat pouch. Reports are that they must drain the pouch above the surface before they can swallow, a process which takes about a minute during which time other seabirds are particularly likely to steal the fish.As a result, pelicans also in turn sometimes pirate prey from other seabirds.In capturing its prey, the brown pelican is said to plunge overboard, diving into the water seizing its food firmly with the strong grasp of its bill.Pelicans in general though are said to be gregarious and nest colonially. Some are said to have a complex communal courtship involving a group of males chasing a single female in the air, on land or in the water while pointing, gaping and thrusting their bills at each other. It has been observed that they can finish this process in a day.In all species copulation begins shortly after pairing and continues for three to 10 days before egg-laying. The male is said to bring the nesting materials while the female heaps the material up to form a simple structure.It has been determined that all species lay at least two eggs and both sexes incubate with the eggs on top of or below their feet.It is said that hatching success of undisturbed pairs can be as high as 95 per cent but because of competition between siblings, usually all but one nestling dies within the first few weeks.The young, according to reports, are fed copiously, but interesting enough sometimes before or even after they are fed they seem to have a seizure that ends with them falling unconscious, a situation which scientists are still unable to understand.Another interesting fact is that some pelican parents sometimes drag older young around roughly by the head before feeding them.Within six to eight weeks after hatching, the young are able to wander around, occasionally swimming, and may even practice communal feeding.Adding to their interesting nature, pelicans have found their way into mythical legends and symbolisation.In fact, one such notion arose in medieval Europe when it was recognised that the pelican was particularly attentive to its young to the point of providing her own blood when no food was available.As a result, the pelican became a symbol of the Passion of Jesus.It also became a symbol in bestiaries for self-sacrifice and was used in heraldry (a pelican in her piety or a female pelican wounding herself.)Another version is that the pelican had the power to kill its young and then resurrect them with its blood, this being analogous to the sacrifice of Jesus. It is for this reason too that the symbol of the Irish Blood Transfusion Service is a pelican.Similarly a folktale from India relates that a pelican killed her young by rough treatment but was then so contrite that she resurrected them with her own blood.It is said that these legends may have arisen because the pelican used to suffer from a disease that left a red mark on its chest. Alternatively it may be that pelicans look as if they are stabbing themselves as they often press their bills into their chest to fully empty their pouch.| 歡迎光臨 MeiMei正妹交友論壇 (http://tt42.infowww.meimei888.com/discuz/) | Powered by Discuz! 7.0.0 |