All about trumpeter swans
As the largest species of waterfowl in North America, trumpeter swans are both beautiful and majestic. They reside mainly in isolated populations in western Canada and the western United States, although they were formerly more widespread. Many states have created overwintering and nesting habitats to regenerate the population. The Trumpeter swan inhabits lakes, ponds, large rivers, bays and sometimes grain fields.
The University of Michigan Museum of Zoology reports that the breeding season of the Trumpeter swan begins in April and May. Unlike most birds, which lack external genitalia, the males of these swans have an erectile, penis-like intromittent organ, which is a special modification of the ventral wall of the cloaca. It probably facilitates the sperm transfer underwater. Trumpeter swans, like all birds, are oviparous. The female lays the eggs and they develop outside of her body. The clutch size, or the number of eggs that are lain by one female at a single time, of the Trumpeter swan can be anywhere from two to ten eggs.
The egg of the bird is an elaborate reproductive cell. The embryo develops into a chick in this self-contained environment. Food and water are provided inside the egg. The shell protects the contents of the egg and allows the exchange of the water vapor and respiratory gases with the atmosphere. The eggs must be incubated in order to keep them warm as well as to protect them from predators. The narrow temperature range that the embryo can tolerate gives the parents the extra responsibility to incubate the eggs to transfer the heat that is necessary for the embryonic development of eggs in the nest.
The nest of the trumpeter swan is a large bulky platform of aquatic vegetation which is lined with down. The nests are usually located on beaver houses, islands or the margin of the lake.
The trumpeter swan travels in parties and small flocks. They are normally sedentary and partly migratory.
The trumpeter swan is almost entirely vegetarian. It eats leaves and stems of aquatic plants, seeds, grain tubers, insects, snails, small reptiles and fish, mollusks, and occasionally crustaceans.
Swans were once hunted for many economic uses. In the past, their feathers were used by primitive people for arrow making and decorations and ornamental wear. The feathers are still utilized for the clothing and bedding industries. Swans are also hunted and sold for food. The bones of trumpeter swans have been found at several Indian archaeological sites. The birds were captured and sold for their plumage as well as their meat.
These birds may be helpful economically since they eat insects as well as some small vertebrate prey. These insects are pests to the agricultural industry, and by eating them, the swans are a form of a natural pesticide or insecticide.
Trumpeter swans have a highly varying population density. Clearing of forests by humans has increased their habitat. This species is protected by the U.S. Migratory Bird Act.
The trumpeter swan has shown that there is hope in conserving species of endangered animals in the future. In the 1930s, this species had become alarmingly scarce in the United States. However, with nearly complete protection of non-migrating birds on western refuges, the population increased from a low of 35 birds in 1954 to almost a thousand in 1972. With the proper legislation, protection and conservation methods such as the establishment of natural parks and refuges, the number of birds is now steady.
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