Bird Migration
Oct 17, 2006
2:00/1:00 MT/PT
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Bird Migration Facts TITLE
What is Migration?
What makes a Bird?
Why migrate
When to Migrate
Where to Migrate
How to Migrate
Dangers of Migration
Scientists
A Girl and Flying Birds, clipartHave you ever seen flocks of geese flying South in the Fall? Have you heard them honking? Have you wondered why there are flying in a formation that looks like a "V"? Have you wondered where they are going?

They, and many other birds, are migrating and you've come to the right place to learn about migration!

What is Migration?

     The word migration comes from the Latin word, migratus which means "to change." The word has special meaning when it refers to animals. Migration is the movement of an animal from one region, or habitat, to another. This happens at regular periods of time, and during a particular season. For birds, this occurs twice a year in the spring and fall.
Animals migrate in order to breed, grow, find food or avoid cold weather.
Let's first review what makes a bird a bird..   Wing feathers     All bird species have feathers.
There are several other characteristics that birds share, but feathers are the only characteristic completely unique to birds.

FactDid you know that not all birds fly? (Emus, Kiwi, the Cassowary ,Ostriches and Rhea's don't). Some birds Baby Hawkswim...like the penguin, which does its flying underwater.
Explore all about flightless birds.
Did you know that other animals besides birds can fly?
Bats, which are mammals and not birds, can fly.

Other interesting adaptations to life in the air are:
Lightweight, yet strong, bones and beaks, which are an adaptation to reduce weight for flying....
Incredible eyes and ears, bird song , bird feet, and nests. Investigate birds...

How are birds classified?Hawk Head
In order for scientists to be able to understand each other no matter what language they speak they have an international way of naming living organisms. The scientific names are written in a language called Latin.
      This system of classification was established by Carl Linneaus in the 1750's when he described many North American birds. Learn more about the science of naming things, "Taxonomy".
Explore the Tree of Life from the University of Arizona.

This is how birds are classified:
Kingdom: Animalia
Phylum: Chordata ( meaning "with a backbone")
Class: Aves (Birds) The Class Aves is currently divided up into 23 orders, 142 families, 2,057 genera and 9,702 species of birds
Order: There are 23 Orders of Birds in the world. For example: Robins are members of the Order called, "Passeriformes". Eagles, hawks and falcons belong to the "Ciconiiformes" order.
Family: A further division... read about Bird Families
Genus: A further specific grouping
Species: The basic unit of all classification. Every bird has its own double name that includes a genus name and a species name. The Robin's name is:
Turdus migratorius
Why do birds migrate?Question marks
     
 Birds seek out places that have warmth, food and are safe for breeding.
     
      Seasonal migration primarily happens in the Northern-Hemisphere, because in the Southern Hemisphere, especially in the tropics, it is always warm enough for an adequateyear -round food supply, and there is little variation in the length of day throughout the year, so birds have plenty of time to eat in a day. So, not all birds migrate.

      During the long days of the northern summer, birds have more hours to feed their young on the abundant insect population. As the days shorten in the north in autumn and food supplies become scarce, the birds migrate south.
A Flying Hawk clipartThere are 4 kinds of migrating birds: (http://www.backyardnature.net/birdmgrt.htm)

Permanent residents, are non-migrating birds who remain in their home area all year round.

Summer residents are migratory birds move north in the spring, nest during the summer, and return south in the fall.

Winter residents
are migratory birds who fly south for the winter.

Transients
are migratory species who nest farther north than our neighborhoods, but who winter farther south.We only see transients as they are passing through.

When do birds migrate?Months
     Each species migrates at a certain time of year and time of day. Some are very irregular in their migration patterns.
     
      Some species start their migration south in early July and some don't migrate until the weather gets too harsh or the food becomes unavailable later in the fall. Experiments show that day length stimulates migration. In the Spring, you might see migrating birds as early as January in Florida!
    Did you know 
clockMost birds fly by night in small flocks. This allows them to eat during the day, and avoid some predators.

How do they keep going?

     Some birds eat along thie route, but some birds eat more just before migration and store a special, high-energy fat in their body because some might not eat for several weeks as they migrate.

Fly South clipartWhere do birds go?
     Many species migrate very long distances. The most common pattern is that birds migrate to the temperate or arctic northern hemisphere to breed in the summer and migrate south to warmer regions, for the winter. often in the tropics or the temperate zones of the southern hemisphere.

Flyways
     There are 4 main Flyways, or routes, in North America that most migratory birds follow between their summer and winter residences.
     They follow certain established migratory routes and pass through at predictable times. These routes tend to avoid land forms that might block their way, such as mountains, or water.
      For soaring birds, such as ospreys, eagles, vultures, and hawks these routes follow paths that take them by hot air rising from land that they need to soar. By spiralling up a thermal and gliding down to the next one, they save energy needed for long journeys.

The Arctic Tern has the longest known migration route. It flies about 22,000 miles each year between its breeding grounds in the high Arctic and its winter grounds in the Antarctic.

Moon abd Birds, clipartHow do birds find their way?
      Navigation is complicated because it requires three things: birds must know their current location, their destination and the direction they must take to get there.
     
Some birds use the sun, the stars to navigate. Some also use the sighting of landmarks like rivers, mountains or coastlines. Some might use smell, while some might follow other birds in the flock.

Wow Some even monitor the Earth's magnetic field using their visual system and with tiny grains of a iron-containing mineral called magnetite in their heads, that might act like a compass.
Not all is known about how birds find their way but they probably use more then one method.
Study navigation... and
Orientation.

How fast do birds fly? Speed ranges from 20 to 50 miles per hour. Larger birds fly faster than smaller birds. If the flock flies for 10 hours a day, then they could fly about 400 miles a day!!!

How high do birds fly?
Radar studies show that most flight occurs at less than 10,000 ft, but some have been recorded flying at 27,000 ft!! Birds on long-distance migrations fly at higher altitudes than short-distance migrants.

RaptorWhat are the dangers of migration?

     Sometimes birds must fly across harsh habitats such as deserts, where there is little water, or oceans, where there is no place to land and little food to eat. Sometimes stormy weather may make the trip difficult. There can be many predators along the migration route.

FlockHow do ornithologists study birds and migration?

     Bird banding or ringing is one method used to study wild birds. Scientists attach a small individually numbered metal or plastic ring to a bird's legs or wings. They also use mist nests as a way to capture birds. This way they can capture and re-capture the same individual and measure and weigh it and gather other important information .

Here are excellent photos of that process.

     Sometimes scientists use satellite tracking for follow birds on their migration routes.

Did you knowBirdwatching is the second largest hobby (gardening is the first) in North America with over 31 million participants. Start watching here...Internet Bird Collection , an on-line audiovisual library of footage of the world's birds.

Study bird behavior in your own backyard...

Develop your bird watching skills with the Directory of Bird Watching Clubs in Idaho.

Head to another Dialogue for Kids topic and become familiar with Birds of Prey.

Take a peek at a career as an ornithologist.
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