Graphics Reference
In-Depth Information
Broad, short wings create more drag than do long thin wings. An albatross's
wings are long and slender and are more suited to efficient flying over very
long distances. The greater the area of wing, the greater the amount of lift
it provides. There are a large number of wing designs as solutions to the
problem of flight, though these generally fall into a few basic types:
• Elliptical wings
• High-speed wings
• High-aspect-ratio wings
•
Soaring wings
Whether the wing is slotted, the degree to which the wing curves, the aspect
ratio of the wing—that is, the proportion between wing length and breadth—
and finally, the wing loading (the total surface area of the wing compared
with the weight of the bird) are all factors that must be considered when we
talk about wings.
Elliptical Wings
Elliptical wings
are short, broad, rounded wings that have a low aspect ratio
and are suited to birds living in dense vegetation or woodland. Many of the
small, common garden birds have wings that fit in this category. They provide
great maneuverability and a high takeoff speed, both characteristics that are
well suited to birds that need to evade predators. Birds such as crows and
pheasants have such wings.
High-Speed Wings
Birds that have wings designed for high speed are capable of a high wing beat
rate, though such an approach to flying is generally rather more expensive in
terms of energy consumption.
High-speed wings
lack any of the slots found in
other wing types; these slots tend to increase drag and therefore slow the bird
down. The world's fastest birds, the peregrine falcon and the swift, both have
this type of wing. The swift has a very distinctive highly curved, streamlined,
and very smooth wing that makes it capable of the high-speed maneuvers it
needs to catch insects in midflight.
High-Aspect-Ratio Wings
Wings with this type of design, far longer than they are broad, are very useful
for flying at slower speeds. They are most suited for gliding; not surprisingly,
many seabirds have this type of wing. Terns have this design, making them
capable of a flying at such slow speeds that when they face into a headwind
the action almost resembles hovering. The albatross also uses this design that
demands very little by way of flapping but makes it able to exploit the very
minimal levels of lift generated from the wave actions at sea. These wings are
able to make the most of the little updraft that exists just above the waves.
Such wings prove to be rather cumbersome during takeoff and landing,
however. Birds with this type of wing often need to taxi to gain enough
airspeed and the required lift to take off.
