100 Things I Never Knew About Bird Migration

Jun 21 18:31 2009 Jill Clow Print This Article

100 interesting things you never knew about the birds in your back yard and their migrations

Introduction

The information in the document has been gathered from various sources on the internet and thrown together using ‘copy and paste’. There is nothing (or very little) truly new on the internet. I am not an expert on birds – only someone trying to appreciate the beauty around us. Until recently I didn’t even know that some birds migrate at night.  Writing this document has given me  more respect for our remarkable feather friends and depressed me for the disrespect we have shown them.  The warning signs are right in front of us – honey bee population has been wiped out by the use of these pesticides and these chemicals have done untold harm to the birds. We need tight regulation of these harmful chemicals before we lose what is truly important – nature and her wonders. Why do so many of us disregard the truly remarkable and beautiful things around us and get excited by stupid mundane things like cars,Guest Posting material goods?

 

 

If you want to help turn things around here are some links:

http://www.birdlife.org/index.html

http://www.worldbirdingcenter.org

 

 

Why Do Birds Migrate?

1.         To access remote food sources.

2.         To avoid cold weather conditions.

3.         To breed in areas more suitable to raise young.

 

 

Which Birds Do It, Which Don’t?

1.         Most birds migrate in some form or another.

2.         Birds that don’t migrate are called sedentary birds.

3.         Some of the birds of the same species may migrate, some not. This called partial migration.

4.         In far northern regions, such as Canada or Scandinavia, most species migrate south to escape winter.

5.         In temperate regions, such as the UK, about half the species migrate – especially insect-eaters that can’t find enough food during winter.

6.         In tropical regions, such as the Amazon rainforest, fewer species migrate, since the weather and food supply there are more reliable all year round.

7.         Only the female Chaffinches in Scandinavia migrate with the males staying where they are.

8.            Migratory birds generally have longer, more pointed wings than non-migratory species, a feature that further minimizes air resistance.

9.            Migratory birds tend to have larger pectoral muscles than non-migratory species.

 

 

When Do They Start and How Long Does it Take?

10.       Bird migration tends to be triggered by the length of days, when the bird has enough energy stores (fat from overeating), favorable winds and other birds to fly with.

11.       There is believed to be some hormonal stimulus to migrate, resulting, at least in the spring, in the development of the gonads.

12.       Birds have an internal urge to overfeed for a period before their migration time. This is known as to become hyperphagic.

13.       Birds usually have 3 – 5% body fat.

14.       Birds usually double this before migration.

15.       Birds also have an internal urge to gather together before their migration time so that they can fly together.

16.       A one-way migration can take anywhere from several weeks to 4 months. The pace of migration tends to be faster in the spring, with the pace picking up as a bird gets closer to its breeding area.

17.            Migration is usually accomplished in a series of flights lasting from several hours to several days. Between flights, birds make pit stops at (often at migration sites) for resting and "re-fueling" which last anywhere from a day to a few weeks.

18.       Global warming has definitely affected when birds migrate. For example Australia's migratory birds are arriving earlier and leaving later.

 

 

Migration Distance and Routes

1.         Bird migration distance varies greatly – from a few kilometers to thousands of kilometers (30,000 in the case of the Arctic Tern).

2.         Birds often have a different route back home from the outgoing route.

3.         Longer migration is genetically programmed into birds as behavior, responding to changing lengths of the days.

4.         Shorter migration often occurs for other reasons such as food or weather.

5.         Some birds only migrate by changing altitude – for example moving higher up the mountain or down the mountain.

6.         Some birds migrate because of wet or dry seasons. For example kingfishers in India move around with the wet season.

7.            Sometimes birds have to migrate further than usual to find food sources – this is called Irruptions.

8.            Migratory birds are genetically programmed to migrate in a certain direction for a certain period of time.

9.         A bird’s first migration tends to be a learning experience, starting with genetic (or parental / peer) control and learning from there. Birds are known to learn good places to stop every year and remember them.

10.       Not all birds are genetically programmed with their direction / time. Some birds figure out the direction themselves from the environment. Tests have been performed on these kinds of birds and they don’t know where to migrate if they have been kept inside.

11.       Many birds are taught their migration routes by their parents.

12.       Many birds use the sun to navigate. They can use the setting sun as an indication of due west.

13.       Many birds use wind direction to navigate.

14.       Many birds use and remember landmarks for navigation.

15.       Many birds can feel the earth’s magnetic field and use that for navigation purposes.

16.       Birds that migrate at night use the stars to navigate.

17.       Indigo buntings are known to use the North Star as their navigation guide.

18.       Birds are known to stop migrating on cloudy nights.

19.       Human beings can teach migration paths to birds and small aircraft have been used to do this with geese.

20.       In the USA there are 4 main flyways (migration routes) and these are termed the Atlantic, Mississippi, Central and Pacific flyways.

21.       Many birds find the Mediterranean sea hard to fly over so they veer the left or right to avoid crossing it.

22.       An average of 75% of birds migrate to the same place to breed.

23.            Migration distances of 200 to 400 miles a day are commonplace among long distance migrants.

24.       Some other birds migrate much more slowly some Robins average 13 miles a day.

25.       A Neotropical migratory bird is a bird that breeds in Canada and the United States during our summer and spends our winter in Mexico, Central America, South America or the Caribbean islands.

26.       There are 200 species of Neotropical migratory birds.

27.            Swallows breed in Europe and spend the winter in Africa.

28.       The ruby-throated hummingbird weighs only 4.8 grams and can use stored fat to fuel a non-stop, 24-hour flight across a 600-mile stretch of open water from the U.S. Gulf coast to the Yucatan Peninsula of Mexico!

 

 

The Risks of Migrating

1.         Half of bird migrants die when heading south for the winter.

 

Collisions

2.         Many birds die from hitting man-made objects – especially buildings. Birds find it very hard to distinguish real sky and reflections in windows. How terribly sad.

3.         98 – 978 million birds die every year in the USA from flying into buildings. How sickening.

4.         Putting window screens, reflective tape, and other things on near windows warns birds and makes your home more bird-friendly.

 

Depletion of Migration Sites

5.         The biggest threat to bird migration is lack of stop-over migration sites.

6.         Birds use migration sites along the flyway to each and to take shelter from predators.

7.         Birds get the energy to fly from their fat reserve and they have to eat a lot at the migration sites to replenish their energy reserves.

8.            Depletion of tropical forests is a huge threat to the populations of migrating birds.

9.            Migration sites are the most important when they are before a natural barrier – for example the Gulf Coast is an important area for migration sites because birds stop there before they fly over the Gulf of Mexico.

10.       Making your own yard more bird-friendly (i.e. providing food and moving water to birds in your yard) really helps birds migrating. Having nectar, fruit trees or plants in your yard will really help migrating birds, as well as having plants that flower year-round.

11.       Coffee plantations have turned out to be excellent migration sites – some of these plantations support up to 150 species of migrating birds. However coffee plantations growing coffee under shade are far more supportive to bird life than the newer shade-free plantations.

12.       Studies in Colombia and Mexico found 94-97% fewer bird species in sun grown coffee than in shade grown coffee.

 

Pesticides

13.            Migrating birds are extremely susceptible to pesticides and it is well known that certain kinds of pesticides cause reproductive failure in birds, wiping out populations.

14.       Birds that prey upon other creatures adversely affected by pesticides are then in turn harmed themselves.  This is known to happen with osprey being poisoned by fish which were poisoned before.

15.       672 million birds a year are killed by pesticides in the US alone. How disgusting.

16.       40 active ingredients in pesticides have been found to be lethal to birds, even when used according to the instructions on the label. Only about a quarter of these ingredients have been banned in the United States, and most are still used elsewhere.

17.       The benefits of pesticides are often cited in terms of their contribution to world food production, and yet it is estimated that crop losses to pests would increase only 10% if no pesticides were used

18.            Scientist Paul Ehrlich has compared pesticides to heroin in that "they promise paradise and deliver addiction." Pesticide use leads to dependency by killing not only the targeted pests but also the natural predators and parasites of those pests and through the development of resistance in the pests.

 

 

The Flying Itself

1.         Flying at night can minimize predatation and overheating.  Many birds that fly at night feed during the day and fly at night.

2.         Many of the smaller birds that eat insects migrate (fly) at night.

3.            Thrushes, warblers, cuckoos and woodpeckers migrate by night.

4.         Most songbirds migrate at night.

5.         Many of the larger birds migrate (fly) during the day by using thermals to gain altitude.

6.         Birds of prey, swallows and crows migrate by day.

7.            Songbirds tend to fly at a height of 500 to 6000 feet.

8.            Shorebirds tend to fly at a height of 1000 to 13000 feet.

9.            Waterfowl tend to fly at a height of 200 to 4000 feet.

10.       Raptors tend to fly at a height of 700 to 4000 feet.

11.       Flying high often allows birds to catch winds and allows the birds to fly in a cooler temperature, which prevents them from being overheated under physical stress.

12.       Larger birds migrate in flocks, often in a v shape.

13.       Flying in a vshape is more efficient aerodynamically and saves energy (12-20%).

14.       Some birds were found to fly 5 km/h faster in a flock than alone.

15.            Songbirds tend to fly at a speed of 10 – 30 miles per hour.

16.            Shorebirds tend to fly at a speed of 20 – 40 miles per hour.

17.            Waterfowl tend to fly at a speed of 30 – 50 miles per hour.

18.       Raptors tend to fly at a speed of 20 – 45 miles per hour.

19.       A tailwind allows the bird to fly faster.

20.       When migrating seabirds fly low above the water but higher over land.

21.            Wildfowl migrate both day and night.

22.       Hawks and other raptors do not like to migrate over water.

23.       The Blackpoll Warbler's over-water flight to South America keeps it aloft for 80 to 90 continuous hours, an effort which researchers Tim and Janet Williams conclude "requires a degree of exertion not matched by any other vertebrate; in man the metabolic equivalent would be to run a 4 minute mile for 80 hours. If a Blackpoll Warbler were burning gasoline instead of reserves of body fat, it could boast of getting 720,000 miles to the gallon."

24.       Birds have the respiratory system in the animal kingdom and a heart six times the size of a human heart (in proportion to overall size).

 

 

Flying is Not the Only Way

1.         Most species of penguins migrate by swimming, up to 1000km.

2.         Some species of grouse migrate by walking.

 

 

We Reap the Benefits

1.         Insect outbreaks can be very dangerous to humans and the environment. Vast areas of natural forests have been destroyed by insect outbreaks.

2.            Outbreak insects are often infected with parasites and diseases.

3.         Birds (especially migrating birds) are the best defense against insect outbreaks.

4.         It is common practice to encourage birds to take up residence or to migrate to a special area to prevent insect outbreaks. This often takes the form of protecting bird colonies, drilling holes for woodpeckers, building nest boxes etc.

5.         One of the most promising forms of insect control is Integrated Pest Management (IPM), in which birds play a key role. The success and economic feasibility of these programs may depend on the number and diversity of birds in an area. Providing hedgerows, woodlots, streamside habitat, and shade trees in an agricultural landscape can provide cover and nesting areas for birds.

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About Article Author

Jill Clow
Jill Clow

About the author:

Jill Clow has been building award winning market stalls located around the country and is now selling her favorite items on her website www.birdprintart.com. Read the original article in context with pictures here:

 http://birdprintart.com/100_things_I_never_knew_about_bird_migration.asp

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