Birds

Birds are living members of a group of dinosaurs called maniraptors, which also includes the small, yet vicious, velociraptor. Like its now extinct family members, birds have feet with three toes and one toe held high in back. Over time, their forelimbs evolved into the wings we see today. The only animal that has feathers, birds are among a select few that have the ability to soar the skies.

The importance of birds

Birds play a vital role in the natural world. Some of the benefits that birds provide include the following:

  • Birds help to pollinate many different species of plants and flowers.
  • Birds eat many insects and small animals, such as mice and rodents, that are considered pests by many. Birds also eat the seeds of many weeds, preventing their spread.
  • Birds and their eggs are often used for food by other animals, including humans.
  • Bird feathers are used by humans for decoration and as a warm insulation in coats, blankets, pillows, and bedding.

Characteristics

Beaks

  • All birds have a beak or bill, a hard external mouth structure composed of an upper and lower jaw that lack teeth.
  • The structure and shape of a bird’s beak can vary greatly depending upon the type of food the bird requires, and other factors of the bird’s surrounding environment.

Feathers

  • The only animal with feathers, birds are found worldwide from tropical to sub-zero regions in water and on land. Made of keratin, the small material as our hair and nails, feathers are shed once of twice a year in a process called molting.
  • To keep their feathers in top condition, birds preen by using their beaks or bills to dip into an oil gland near the base of their tails and spread it over their feathers. This oil makes their feathers waterproof.
  • Not all birds have an oil gland: some have feathers that contain a fine powder, keeping them waterproof, too.

Flight

  • Most birds can fly, with the kiwi, ostrich, and penguin being among the exceptions.
  • Birds are known for having "hollow" bones, an adaptation where air spaces have replaced part of the bone. This feature reduces their weight, allowing them to fly with greater ease.

Classification

Birds are grouped in a class of vertebrates called Aves. Currently, this class is subdivided into 23 orders, though it should be noted that roughly half of the world’s bird species fall under a single order, Passeriformes. Members of this order are known as passerines, or perching birds.

Birds that are classified in orders other than Passeriformes can generally be grouped as non-passerines. In turn, these orders contain families of bird species, many of which make their home in the Province of Alberta.

Life cycle

Birds begin life inside a hard shell made of calcium carbonate. A shell acts as a womb that needs just oxygen and heat to hatch the bird inside. Eggs come in many different colours and shapes.

Depending on the species of bird, either the mother, father, or both will incubate the egg by sitting on it and keeping it warm and safe from predators. They even turn the egg to make sure it’s staying warm and developing properly. Birds also develop a temporary bare patch of skin called a brood patch that allows them to sense egg temperature and transfer heat more easily.

Incubation can last from 10 to 80 days, depending on the size of the egg: the bigger the egg, the longer the incubation time. After hatching, they birds are fed by one or both parents until they grow feathers and are strong enough to fly.

 

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Posted: August 20, 2009