kangaroos

I am switching to an animal that has a more similar body structure to human's. A kangaroo is a warm-blooded mammal and a tetrapod.
There are about 63 different species of kangaroos.
I am focusing on the Red kangaroo or Macropus rufus. They are one of the largest species of kangroos.
Taxonomy:
Kingdom Animalia
Phylum Chordata
SubPhylum Gnathostomata
Class Mammalia
SubClass Marsupialia
Order Diprotodontia
Family Macropodidae
Genus Macropus
Species rufus

Body Plan/ Sensory System:

I made this diagram to illustrate the basic body parts of a red kangaroo.

Respiration and circulatory system

Through lung, but have special way of breathing to save energy when they hop.
1. When its feet push off from the ground, air is pumped out of the lungs.
2. As its legs stretch forward, the lungs expand and fill.
Chest muscles are not needed to move air in and out.

Feeding

- They eat only plants, mainly grass and constantly are eating every waking moment.
- Teeth and jaws are designed to make them eating machines.
- Lower jaw is two bones joined by a flexible band that lets the two halves move separately – gap between the two teeth.

- They have replacement teeth – when their molars wear out, the molars in the back slide forward into space. They produce about 16 molars during their life time.

Process:

1. The lower jaw spread making room for a bigger mouthful.
2. Upper and lower teeth snip plants like scissors.
3. Tongue pushes the plants into wads
4. Jaws slide side to side, grinding plants with ridged molars.
5. After swallowing, first part of digestive system only holds the food. One wad at a time is coughed up and chewed more.

***Locomotion

- Comfortable cruising speed is 16 mph – 2 hops per second, each about 12 feet (4m) long.
- when searching for food: 12 mph - taking 5 to 6.5 foot leaps
- Top speed 44 mph in an emergency, for a few hundred yards
- Can jump up to 10 feet high
- Swimming kangaroo kicks its hind legs alternately.
- Walking on all fives-A typical kangaroo is unable to walk, only possible when they are fight, for a few seconds. At slow speeds it uses its tail to form a tripod with its two relatively small forelimbs. It then swings its heavy hind legs forward together. This called “crawl-walking.”
This is a how a kangaroo crawl- walk:

- Hop: Tendon, acts like a rubber band, attaches to muscles, muscles move bones.


Kangaroo resting = human crouches body bent at knees and the hip.


Kangaroo is always ready to hop.

1. To launch, muscles pull on the leg bones and straightening them. Tendons stretched stores energy.
2. Tendons contracts, throws the kangaroo in air and forward without the use of any other energy
3. Legs swings forward automatically
4. Tendons are stretched again when landing.

Reproduction

Marsupials

Females are always pregnant after they are 2 years old with a normal birth interval of 8 months. She usually have babies in 3 different stages, one in her womb, one in her pouch, and one at her side.

Embryo grows inside womb, leaves after 30 to 40 days.

Blind, hairless joey, barely size of a bean, crawl through mother’s fur for a distance of 6 to 7 inches (15 or 20 cm), a time of 2 to 3 minutes into the pouch. Well developed nostrils and forelimbs. Lungs are developed enough to breath in air during the climb. Eyes, ears, hind limbs and tail are undeveloped. Skeleton is completly cartilagenous.

Sucking on nipple, joey gets all the nutrients needed to grow from mother's milk. Mother sometimes pokes her head inside the pouch to lick up the waste.

Joey first releases the nipple voluntarily around 70 days. Eyes open around 130 days. This joeys is 105 days.

First protrudes its head from the pouch around 150 days.
Leaves the pouch for the first time by falling out when time is ready, usually after 190 days. This only lasts few minutes at a time. The joey goes back into the pouch and stays there for another few months.
At around 8 months old, the mother forbids the joey from entering the pouch again.
At 1 year old, a red kangaroo is fully weaned.
At 18 months, the young kangaroo is almost fully grown.
At around 2 1/2 years, he or she is ready to mate.

Images are from Markle, Sandra. Outside and Inside Kangaroos. New York: Atheneum Books for Young Readers, 1999.

Communication

Sounds are used.
Mothers make clicking or clucking noises to call their joeys to them.
Thumping of feet to warn others of danger
Smell: how they make friends

Other information
-Color: Males are reddish brown. Females are blue-gray to brown.
-Size: 4 to 7 feet tall with tails up to 3 meters.
-Weight: Adult males 150, females 80.
-Life span: 20 years old, 6 to 8 in the wild.
-Kangaroos live in 2 to 30 members groups called mobs.
-1 dominant male that fathers all the joeys in the mob.

Bibilography:

Domico, Terry. Kangaroos: The Marvelous Mob. New York: Facts On File, Inc., 1993.

Jango-Cohen, Judith. Kangaroos. New York: Marshall Cavendish Benchmark, 2006.

Landtier, Patricia and Lehne, Judith Logan. The Wonders of Kangaroos. Milwaukee: Gareth Stevens Publishing, 2001.

Markle, Sandra. Outside and Inside Kangaroos. New York: Atheneum Books for Young Readers, 1999.

Penny, Malcolm. Secret World of Kangaroos. Austin: Raintree Steck-Vaughn Publishers, 2002.

Spilsbury, Richard and Louise. A Mob Kangaroos. Chicago: Heinemann Library,2004.

Stone, Tanya Lee. Wild Wild World: Kangaroos. San Diego: Blackbirch Press, 2003.