http://www.ck12.org Chapter 12. Understanding Biodiversity: Animals: Birds
Cell Biology
Turkey vultures have eukaryotic cells. Eukaryotic cells have many organelles ( parts in a cell that are like tiny
organs). One organelle is the mitochondria, which makes energy for the cell. Another organelle is the ribosome,
which makes protein. The nucleus, which is one of the most important organelles in a cell, is where the DNA is. The
endoplasmic reticulum transports proteins. Mitosis is when the cells divide either to grow or for cell repair. Meiosis
is where the cells divide for reproductive purposes to make sperm and eggs, cells with only half of the chromosomes
of the original cell.
Evolution
Turkey vultures evolved from the ancient bird calledTeratornis merriami. All birds evolved from a dinosaur that
lived in the late Jurassic called Archeopteryx.Archaeopteryxhad the flight feathers of a bird, but it was missing the
correct collar bone for flight. The close relativeMicroraptorwas able to fly with not just its arms, but also its legs.
Ecology
The turkey vulture’s prey is mainly carrion, but it will rarely kill small animals and will eat fruit. The turkey vulture
is threatened by humans (traps, power lines, poachers). Great horned owls and raccoons will kill young or eat eggs.
The turkey vulture cleans up decaying animals, so disease does not spread.
Turkey vultures lay 1-3 eggs in a cave or hollow tree. They do not build nests or rarely do. The eggs take about
30-40 days to hatch. The parents will feed and take care of the young for 70-80 days, and independence comes after
80-90 days. Two out of three of the young will most likely survive to adulthood. Turkey vultures can live up to 17
years in the wild and about 20 years in captivity.
Anatomy and Physiology
Birds have a four-chambered heart. A crop is a sack in the throat that carries food for young and for a stage of
digestion and for food storage. A gizzard is basically a stomach and a primary grinding stage for digestion. They
may have stones in them called gastroliths. It also has intestines, eight different air sacs for lots of air, and a vent
(where waste leaves the body).
Of course all birds have feathers, but most people don’t know how the feather is shaped and created. The five types of
feathers are contour feathers (the flight feathers), down feathers (for insulation), semi-plumes (between contour and
down feathers), bristles (located on head to protect objects to get in eyes and nostrils), and filoplumes. All feathers
are made from the follicles in the bird’s skin. The feathers have two main parts, the quill or rachis (the spine of the
feather), and the vane (all the fine, hair-like strands). At each end of the larger barb are smaller barbs (barbules) that
weave together for a tight fit. At each end of the barbules are hooks that keep the feather from falling apart.
Vultures have bald heads so that meat does not stick to the head. From the side view of a turkey vulture, you can see
through nose (nostrils), which means that it’s well developed, which is not common for birds.
Behavior
The turkey vulture roosts in the morning alone or with other vultures in large or minimal numbers. When it’s gliding,
the turkey vulture’s wings are angled in a slight V shape. With its sensitive nose (which is not common among most
birds) it finds it’s food. Since the turkey vulture can’t really hunt (or seldom does), it smells for carrion (decomposing
carcasses). When it finds a carcass, it will land and start to eat it. If the animal that killed the prey is still eating the
kill, the turkey vulture will wait its turn. The turkey vulture is often evicted from a kill by black vultures and other
birds and animals. It communicates with grunts and hisses and bark-like calls.