small this loon's wings are for its heavy body?
To learn the general principles of bird flight,
you may wish to start with our Bird Flight Primer
Loon bodies are adapted for diving and fishing underwater. Feathers
are very light, and flight feathers in particular are extremely buoyant.
If loons had large wings, they wouldn't be able to stay submerged to
chase fish. So to dive well, they have short wings and heavy bodies.
Common Loons weigh about 9 pounds with a 46-inch wingspan. To put this
in context, Great Blue Herons average 5.3 pounds with a 72-inch wingspan,
and Sandhill Cranes weigh 10.6 pounds with a 77-inch wingspan. Those
relatively small loon wings must support a lot of bird compared to
the huge wings of the crane and heron!
Imagine a huge parachute floating down with a 100-pound box. It can take a
long time to hit the ground. Now imagine that same box attached to a tiny parachute.
It won't "float" at all but drop fast! Herons and cranes are like
the box with the big parachute, and loons like the same box with a tiny parachute.
Thanks to their tiny wings, loons simply can't glide or soar, but must ALWAYS
flap to stay aloft.
Loon wings are so small compared to their body weight that even with strong
flapping they can't support the weight of the loon in the air if they're missing
a couple of feathers. Loons must work terribly hard to stay up if only one
flight feather is missing. This is why loons molt all their flight feathers
in winter, when they are on the ocean and can get wherever they want by swimming.
loon is just exercising its wings. It has to flap hard while running
to actually get aloft.
challenge for loons is getting up in the air in the first place. In
order to get lift, they need a lot of air rushing beneath their airfoil
wings. Even running as fast as they can is usually not enough. They
also need the boost of wind. So first they feel which way the wind
is blowing, and then run straight into it while flapping powerfully.
The stronger the wind, the shorter the "runway" they need
to takeoff. Sometimes when young loons are late in developing (usually
from a late nesting or when food is scarce), their flight feathers
are barely ready for use when the first autumn ice is starting to form
on their lake. Then without help, they are stranded. This is also why
the orientation of a long, narrow lake is critical to a loon pair.
If the lake runs parallel to the way the wind most normally blows,
it is easy for loons to come and go. If the lake runs at right angles
to the normal wind direction, it may not give the loons enough of a
loons get up in the air, they are strong fliers and can cover hundreds
of miles in straight flight. But migration is very energy intensive
for them, because they have to flap every inch of the way.
Also, because loons fish, they must have strong, heavy beaks and necks. They
don't need to strike fish with the force that herons use, and don't have
particularly long necks, so they don't pull their necks back in a crook.
But they DO fly with their neck a bit below horizontal, drooping.
have to be careful of where they come in for a landing (in their
case, should we say "lake-ing"?), because they can only
take off where there is a good surface of water for a runway. Sometimes
loons hear frogs and see a nice shimmering surface sparkling like
their favorite lake, only it's really just a wet parking lot sparkling
with lights. If they don't figure this out in time, their legs and
feet can be damaged by the crash landing (remember, they were expecting
to land on water). And in struggling to get somewhere, they often
get bad abrasions on their bellies and feet.