Graphics Reference
In-Depth Information
Soaring Wings
Wings that are suited to soaring are large, with deep slots at their tips. They
are shorter and broader than the high-aspect-ratio wings and, rather like
elliptical wings, they provide valuable assistance during takeoff. Many larger
raptors, such as buzzards, eagles, and vultures, have such wings. Soaring is
a mode of flying suited to those larger species that fly over land. The heat
from the land provides plenty of thermal lift, and these large broad wings
are capable of exploiting the maximum lift such thermals provide. Birds
with this wing design also often have broad tails that provide additional
maneuverability and lift.
Taking Of
Takeoff is a very demanding part of flying that often requires a great deal of
energy, particularly for birds that are restricted to taking off from the land
or water. Launching from a perch or an elevated position aids the process.
Birds have developed many different ways of becoming airborne, but they
all have one thing in common: All birds need to have air traveling over the
wing at sufficient speed to create the necessary lift. So, gaining momentum
to get the air moving across the wing is a critical factor. Some of them simply
fall into space from a cliff face or a high perch. For some other land-based
birds this may not be possible; they are faced with the option of jumping to
take to the air, but jumping takes a lot more energy. Small birds may achieve
FIG 4.52
Takeoff sequence of a
pigeon jumping into the air.
