Reptiles

Birds have long been revered or reviled in our finicky societies. Birds assume a variety of roles in mythology and religion.
They play a central part in some creation myths and frequently appear as messengers of the deities. They are
often associated with the journey of the human soul after death. Birds also appear as tricksters and oracles.
Ravens and other species that feed on carrion, the flesh of the dead, may be symbols of war, death, and misfortune,
as well as mediators between humans and the supernatural world. Other birds represent strength, love, and wisdom.

It's easy for us to look to the sky sometimes and wish we had the lives of birds - free to do as they choose, fly
to wherever they want to go, and seemingly have little to do in life than eat and chirp. But the reality is much
more harsh and brutal for many of these feathered tough-guys.

Take, for instance, the tiny hummingbird. His life looks easy enough, flitting from flower to flower, or to your feeder,
sipping nectar and looking beautiful. The fact is that these animals lead very demanding lives. It takes a lot of food
to keep those little bodies hovering, and a great many wing beats; 15 - 80 times per second depending on the
species, and because of this they have extremely high metabolisms. The average hummingbird feeds in many
small meals, consuming invertebrates and up to five times their own body weight in nectar each day. This generally
requires them visiting up to 1000 flowers every day! They spend an average of 10-15% of their time feeding
and 75-80% sitting and digesting. Hummingbirds are capable of slowing down their metabolism at night, or any
other time food is not readily available. They enter a hibernation-like state known as torpor. During torpor, the
heart rate and rate of breathing are both slowed dramatically (the heart rate to roughly 50 - 180 beats per minute,
down from around 1000), reducing the need for food. If they did not do this, the animal could literally starve to death overnight!

But that isn't all this little dynamo has to endure. In the fall and in the spring hummingbirds like the ruby-throated
need to migrate in order to continue finding the flowers and insects needed for survival. This requires them to fly
from Canada to Mexico and South America. Try doing that when your wingspan is only 8-11cm (2.5 - 3.5 inches)!

The hummingbird isn't the only long distance migrator, however, Not by a long shot. The bird which migrates the
farthest is actually the Arctic Tern. This bird has a circumpolar distribution, breeding colonially in Arctic and
sub-Arctic regions of Europe, Asia, and North America (as far south as Brittany and Massachusetts). The
species is strongly migratory, seeing two summers each year as it migrates from its northern breeding grounds
to the oceans around Antarctica and back (about 24,000 miles) each year. This is the longest regular migration
by any known animal. The arctic tern flies as well as glides through the air, performing almost all of its tasks in
the air. The arctic tern lands once every one to three years (depending on their mating cycle) to nest at the
northern shores of Antarctica. Once they have finished nesting they take to the sky for another long southern
migration. This is a huge undertaking for an animal that are only 33-39 cm (13-15 in) in length and have a
wingspan of 76-85 cm (26-30 in)!