We’re passionate about birds and nature. That’s why we opened a Wild Birds Unlimited Nature Shop in our community.
8108 Abercorn Street, Ste 210
Savannah, GA 31406
Phone: (912) 961-3455
Fax: (912) 961-3122
Email: Send Message
Mon - Sat: 10:00 am - 6:00 pm
Sun: 12:00 pm - 5:00 pm
We are located between Home Goods and Party City, at the corner of White Bluff & Abercorn, in the Abercorn Common Shopping Center.
Bird Migration is a fascinating time for many bird watchers. It is also a fun time for many people who feed the birds. Migration can happen right in your own backyard!
How Birds Migrate
A streamlined body shape and a lightweight skeleton composed of hollow bones minimize air resistance and reduce the amount of energy necessary to become and remain airborne. Well-developed pectoral muscles, which are attached to a uniquely avian structure called the furculum, power the flapping motion of the wings. The long feathers of the wings act as airfoils which help generate the lift necessary for flight.
Birds have a large, four-chambered heart which proportionately weighs 6 times more than a human heart. This, combined with a rapid heartbeat (the resting heart rate of a small songbird is about 500 beats per minute; that of a hummingbird is about 1,000 beats per minute) satisfies the rigorous metabolic demands of flight. Unlike mammalian or reptilian lungs, the lungs of birds remain inflated at all times, with the air sacs acting as bellows to provide the lungs with a constant supply of fresh air.
Flight = Mobility
Flight affords mobility and has made possible the evolution of avian migration as a means of access to distant food resources. It also means avoiding the physiological stress associated with cold weather. Variations in the patterns of migration are numerous. Some species move only a few kilometers up and down mountain slopes. Others will travel hundreds or even thousands of kilometers, some over vast bodies of water or tracts of inhospitable terrain.
How Do Birds Prepare For Migration?
To prepare for migration, birds become hyperphagic. That means they eat more food, which is stored as fat for their long journey. Fat is normally 3% to 5% of the bird's mass. Some migrants almost double their body weights by storing fat before migration. 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!
When Do They Migrate?
During the day:
Many soaring birds, such as hawks, migrate by day. They travel inland by flying and catching thermals that occur only over land. (Thermal updrafts are rising columns of warm air that spiral upward and lift the birds up so they can fly without flapping, saving energy. Raptors also use thermals when they are not migrating.) Hawks and other raptors do not like to migrate over water. When they reach Mexico and Central America, where the land narrows between the Pacific Ocean and the Caribbean Sea, the hawks are funneled over this land bridge. As so many birds try to stay inland, you will see huge concentrations of raptors, sometimes as many as 100,000 in one day.
Insectivores, such as swifts and swallows, also fly during the day, feeding on insects as they fly.
Flocking birds such as waterfowl and some finches fly during the day, too.
During the night:
Most songbirds travel at night. They spend the daylight hours resting and searching for food in the unfamiliar places where they stop to rest. It is thought that the lower night temperatures and stiller air make better flying conditions.
How Far Do Birds Migrate?
It depends on the bird species.
The arctic tern may hold the record for longest migration distance since it flies about 30,000 km (18,600 miles) each year traveling between its arctic breeding ground and non-breeding area in the Antarctic. This amazing feat is possible because terns eat fish and can feed during their long journey.
Most songbirds don't fly to their non-breeding grounds non-stop. They stop a number of times to rest and feed during migration. The places they stop are called stopover sites, or staging areas. Birds remain at stopover sites for varying amounts of time based on the weather and how much fat they have stored. Some birds stop only one day to rest and feed, and then continue their migration. Others will remain at stopover areas for weeks. Most Neotropical migrants stop along the way to rest and feed.
Some birds are short-distance migrants and migrate only as far as they need to find food such as insects, seeds and berries.
At What Altitude Do Birds Migrate?
Some geese and ducks fly at incredible heights. Bar-headed geese have been recorded as high as 29,000 feet when they migrate over the Himalayas! That's five miles above our heads, even higher than Mount Everest!
Most night-migrating songbirds fly below 2000 feet (600 m) when flying over land. Some will fly as high as 6,500 feet (1,980 m). Occasionally, they may fly higher to reach favorable winds.
The wind sometimes causes birds to fly at certain heights. When the bird is flying into the wind (called a headwind), it flies very low. When the wind is blowing the same direction as the bird, pushing it along (called a tailwind), it will fly high, where the wind is the fastest.
How Fast Do Birds Fly?
In still air, most songbirds fly at 20 to 30 mph. Waterfowl and shorebirds can fly at 30 to 50 mph. A tailwind allows the bird to fly faster.
How Do Birds Navigate?
Birds have excellent vision and rely on visual landmarks for local and long-distance migration. They use key land features such as mountains, rivers, coasts or even large buildings.
There are three types of "compasses" a bird uses to find its way. Birds can use the sun, the stars and the Earth's magnetic field.
1. Birds use the sun as a compass. They use the positions of the sun during the day to navigate. They also can use the setting sun as an indication of due west.
2. Night flyers use celestial navigation, which means they find their way by knowing the patterns of the stars in the sky, and by knowing special stars like the North Star. In their first year of life, birds memorize the position of the constellations in relation to the North Star. These star patterns stay the same even though the Earth moves through space, making the constellations appear to move to different spots in the sky during the year.
3. Birds have tiny grains of a mineral called magnetite just above their nostrils. This mineral may help them to navigate using the Earth's magnetic field, which tells the bird what direction is true north.
Petrels and pigeons can use their sense of smell to find their way, but it is used only in addition to the sun, stars and magnetic field.
Hazards of Migration
Collisions with tall buildings, windows, and other structures, being shot or trapped by hunters, and getting struck by automobiles are a few of the numerous human-made dangers. Unfortunately, many birds cannot distinguish the difference between real sky and a reflection of the sky in a window.
It is estimated that each year, in the United States alone, during migration 98 to 976 million birds fly full tilt into windows and are fatally injured.
We can minimize these collisions by breaking up the reflection on the outside of the window with a non-reflective window coating (such as Window Alert window clings), window screens, flash tape and bird netting.
Planting trees and installing window awnings to block the sun from hitting the window may eliminate some reflection. Putting a bird feeder on or within a few feet of a window helps to slow birds down and lessen the effect of impact.
Also, A migrating bird faced with the dilemma of a stopover site having disappeared may not have any viable options. Without places along the way that provide an adequate food supply for the quick replenishment of fat reserves, shelter from predators, and water, these birds are probably not going to make it.
Loss and degradation of stopover habitat not only can result in more birds dying while on migration, but it can also have serious repercussions in terms of nesting success. For example, birds heading north are already constrained by the relatively short amount of time available to get to the breeding grounds, establish a territory, pair with a mate, and get on with the further demands of raising young. Late arrival, or arrival in poor condition, on the breeding grounds because of inadequate food and rest en route, is likely to jeopardize a bird's ability to reproduce.
Conservation = Economic sense
The conservation of migratory birds depends on conservation of habitats, but parks and reserves alone will not provide adequate space for protection. The fate of migratory birds and other wide-ranging species depends upon the quality of human-managed habitats.
You can create and restore habitat at home, at your workplace and in your local park or wildlife refuge. You can make any property attractive to birds by offering water, shelter, food and nesting habitat.
Some points to help birds
- You can start by evaluating your property. It is important to remember that a diversity of habitat encourages a larger variety of birds.
- Dead trees and brush piles provide shelter, nest sites and food (insects) for migrating birds.
- Providing water can be as simple as putting out a bird bath or as complicated as installing a pond with a creek and waterfall.
- Herbicides, fungicides and pesticides - can be lethal to birds.
- Put out bird feeders, seed, fruit and nectar feeders, and fruit.
- Landscape the yard with native evergreen and fruit bearing trees, shrubs, grasses and vines.
- Design the garden so that plants flower and fruit throughout the spring, summer and fall.
- Having a source of water (especially a moving source) can help attract more migratory birds.