North American Game Species Series
WILD TURKEY
(Meleagris Gallopavo) 
| Subspecies Typical to North America | Ranges where they are found |
| Turkey Anatomy and Physiology| Outward Appearance | Skeletal System | Musculature System |
| Nervous System |Circulatory System | Respiratory System | Digestive System |
Next Article:Wild Turkey Behavior & Habits

Robert Hoague with Wild Turkey (probabily 1980)So,You have decided to hunt Wild Turkey with the Bow and Arrow!

You must appreciate a challenge, for that is exactly what you have set your self up for. Many Bowhunters share my belief that Turkey are by far and away the most difficult specie to pursue with archery tackle. So good luck, you will probably need it!

Subspecies Typical to North America and the Ranges in which they may be found.

Some believe the Wild Turkey's name came from the Indian's name "furkee" or "firkee". Also this bird was confused with guinea fowl from the country Turkey. Regardless, Turkey are a native specie to North America.

There are six Subspecies of Wild Turkey found in North America. They are:

Originally Wild Turkeys inhabited predominately Mexico, the Northeastern, Southeastern, Midwest, and Southwestern Regions of the United States. Used to some extent by Native Americans, Wild Turkeys were harvested much greater by America's first European settlers. So much so that by the early 1800's began disappearing from the East and by the late 1800's from the Midwest.  By 1920, They no longer could be found in 18 of their home-range states.  In the 1940's trapping and transfer techniques were applied by Wildlife Management Personnel to restore wild turkey populations. Turkeys have been successfully transplanted to almost all 50 states.

The six subspecies Ranges are listed below.


Turkey Anatomy and Physiology

Wild TurkeyOutward Appearance

In adult turkeys the head and neck are essentially naked, the feathers being reduced to hair like bristles. The tarsus is equipped with spurs, and the tail feathers can be raised to form a vertical fan during courtship or aggressive displays. The bird has black to buff-colored feathers on the tips of the wing coverts and on the tail.

Close inspection of the turkey's plumage reveals a rainbow spectrum of color subtly displayed over much of the male's body, while the female is predominately brown to facilitate her roosting needs. The male has along wattle at the base of the bill and additional wattles on the neck, as well as a prominent tuft of bristles resembling a beard projecting downward from its chest.

Skeletal System

The skeleton gives a Turkey protection, support, and movement. It's also a site for calcium storage and the production of red blood cells.  A Turkey's skeleton is made of bone. Many of the bones are fused or modified for greater strength and rigidity in walking, jumping, running, perching, and especially flying.

Musculature System

Flight muscles:

Muscle mass is divided between the flight and leg muscles.

Leg muscles:

Turkeys have strong leg muscles for as the majority of their time is spent on the ground. Turkeys have well developed muscles running the length of the leg. The toes are controlled by a complex series of tendons attached to muscles in the upper part of the leg.

Tail muscles:

Complex rump muscles raise, lower, and spread the tail during flight, take offs, landings, and courtship.

Nervous System

The nervous system of Turkeys is divided into two basic parts:

  1. the central nervous system (brain and spinal cord) and
  2. the peripheral nervous system (nerves and ganglia).
Important and relatively large structures of the brain include the cerebral hemispheres, optic lobes, and cerebellum.

The cerebral hemispheres (cerebrum) are the dominant coordinating centers of the brain. The cerebrum controls most of the body's activities as well as instinctive and conditioned behavior.

The optic lobes receive and process sensory information from the eyes.  The lobes control eye and neck muscles, enabling birds to quickly track moving objects or avoid danger. In recent years considerable research has been done on how the optic tectum of birds is specialized to respond to moving objects, and distinguishes these stimuli from self produced motion.  This brain structure is involved in orienting the bird toward or away from moving stimuli.

The cerebellum controls the Turkey's posture and balance.

The spinal cord extends the length of the vertebral column with bundles of both motor and sensory nerves.

Circulatory System

The circulatory system is similar to those in other vertebrates. As in mammals, birds have a four-chambered heart; however, a Turkey's heart is proportionately larger and more powerful.

Birds usually have higher metabolic rates than mammals and need larger, more efficient hearts.

Birds require large amounts of energy for flight, and need efficient oxygen circulation.

Birds normally maintain a body temperature of 380C to 420C (100.40F-107.60F).  They thermoregulate in a variety of ways.

Arteries and veins in the head and legs of many birds form heat exchangers called retia mirabilia. A net of vein and arterial vessels lie side by side, allowing outgoing arterial blood to pass heat to the incoming venous blood. This cools the outgoing blood and warms the incoming blood, minimizing heat loss in areas with little or no feathers.

Birds also stay warm by increasing their activity rate (metabolism), fluffing feathers to trap insulating air, shivering, or tucking exposed parts, such as faces and legs into feathers.

To stay cool, birds can decrease their activity rate, sleek feathers flat to get rid of trapped air, or pant.

Respiratory System


The two figures above display a generic representation of the respiratory system of birds. They are generally comprised of a number of sacs in addition to the lungs found in mammals.

DIGESTIVE SYSTEM:

The Pregastric System

The mouth of birds is distinctly different from mammals. They have no teeth and their jaws are covered by a beak, which is seen in remarkably different forms. Birds do not really masticate, and mechanical disruption of food is accomplished by the beak and gizzard.

The esophagus is large in diameter, particularly in birds that swallow large meals. Swallowing is accomplished by esophageal peristalsis, and in most birds appears to be aided by extension of the neck. Most but not all birds have a crop, which varies from a simple expansion of the esophagus to one or two esophageal pouches. Food being swallowed is diverted in to the crop depending on the state of contraction of the stomach, then later propelled into the stomach by waves of peristalsis in the crop.

Turkeys have an additional storage chamber (a sac like swelling of the esophagus) called the crop.

Stomachs

Birds have a glandular stomach, or proventriculus, and muscular stomach or gizzard. The glandular stomach, which receives food from the esophagus, secretes mucus, HCl and pepsinogen, similarly to the mammalian stomach.  The gizzard is a disk shaped, very muscular and in many birds contains small stones that facilitate grinding of foodstuffs. One of the gizzard's two orifices receives ingest a from the glandular stomach and the other empties into the duodenum. A complex cycle of contractions involving the two stomachs force feed back and forth between the two, grinding it and increasing exposure to digestive enzymes. There is also periodic retropulsion of duodenal contents back into the stomachs, again presumably facilitating mixing of ingest a with enzymes.

The stomach has two chambers:

  1. The first chamber is the glandular stomach, or proventriculus, which produces gastric juices for chemical digestion.
  2. The second chamber is the muscular stomach, or gizzard, which mechanically digests food items.
Food moves back and forth between the two chambers until properly digested.

Turkeys have more heavily muscled gizzards, which may contain substantial quantities of grit, pebbles, or sand that aid in the breakdown of hard foods.

The intestine is arranged in a number of U-shaped loops. Digestion is completed in the intestine, and nutrients are absorbed through the gut wall into the bloodstream.

Small Intestine

Birds have a small intestine that seems very similar to the small intestine of mammals. A duodenum, jejunum and ileum are defined, although these segments are not as histologically distinct as in mammals. The proximal small intestine receives bile from the liver and digestive enzymes from the pancreas, and the absorptive epithelial cells are decorated with essentially the same battery of enzymes and transporters as in mammals.

Large Intestine

The large intestine consists of a short colon and, typically, a pair of ceca. Short villi extend into the lumen of the colon, unlike what is seen in mammals. The cloaca is a expanded, tubular structure that serves as the common opening of the digestive, reproductive and urinary systems.  It opens to the outside of the bird as the vent.

As in mammals, the large intestine's primary function is absorption of water and electrolytes. Antiperistalsis that originates in the cloacais a prominent pattern of motility in the avian colon and has been suggested to assist not only in filling the ceca, but to flush urine from the cloaca into the large gut for absorption of water. In some birds, the ceca appear dispensible and can be removed without apparent harm. In other species, the ceca are important sites for fermentation, and the volatile fatty acids generated from microbial digestion of cellulose contributes significantly to energy demands.

Both the liver and pancreas are proportionately larger than in mammals.

In review, many of the above facts might seem dry and of little consequence to the Bowhunter. However when taken in context with other information regarding Habitat, Behavior, & Diet; some of these facts provide keys to tracking down the Wild Turkey in the field.

Questions? Comments? Post other Turkey Hunters at the Wild Turkey Network Message Board!

Next: Wild Turkey Behavior & Habits

| Top | Subspecies Typical to North America | Ranges where they are found |
| Turkey Anatomy and Physiology| Outward Appearance | Skeletal System | Musculature System | Nervous System | | Circulatory System | Respiratory System | Digestive System |
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